Sk70sr-2 Shop Manual

HYDRAULIC EXCAVATOR
MAINTENANCE SPECIFICATIONS
SHOP
MANUAL model SK70SR-2
INDEX
1 SPECIFICATIONS SECTION
SYSTEM
2 MAINTENANCE SECTION
3 SYSTEM SECTION
4 DISASSEMBLY SECTION
DISASSEMBLING
5 TROUBLESHOOTING
6 ENGINE SECTION
7 PROCEDURE E / G TROUBLESHOOTING
OF INSTALLING
OPTIONS SECTION OPT.
Book Code No.S5YT0015E01

0-1
Copyright © 2015 Kobelco Construction Machinery Co.,Ltd. All rights reserved. [S5YT0015E01] [0713CsCshWbYs]
GENERAL SAFETY INFORMATION 3) CAUTION- Indicates a potentially hazardous
situation which, if not avoided, may result in mi-
nor or moderate injury. It may also be used to
alert against possible damage to the machine
Do not operate or perform any maintenance on this and its components and is represented as fol-
machine until all instructions found in the OPERA- lows:
TOR’S MANUAL and this MANUAL have been thor-
oughly read and understood.
Improper operation or maintenance of this machine (4) It is very difficult to forecast every danger that may
may cause accidents and could result in serious in- occur during operation. However, safety can be en-
jury or death. sured by fully understanding proper operating pro-
Always keep the manual in storage. cedures for this machine according to methods
If it is missing or damaged, place an order with an recommended by Manufacturer.
authorized our Distributor for a replacement.
(5) While operating the machine, be sure to perform
If you have any questions, please consult an autho-
work with great care, so as not to damage the ma-
rized our Distributor.
chine, or allow accidents to occur.
(1) Most accidents, which occur during operation, are (6) Continue studying the manual until all Safety, Oper-
due to neglect of precautionary measures and safe- ation and Maintenance procedures are completely
ty rules. Sufficient care should be taken to avoid understood by all persons working with the ma-
these accidents. Erroneous operation, lubrication chine.
or maintenance services are very dangerous and
may cause injury or death of personnel. Therefore
all precautionary measures, NOTES, DANGERS,
WARNINGS and CAUTIONS contained in the man-
ual and on the machine should be read and under-
stood by all personnel before starting any work with
or on the machine.
(2) Operation, inspection, and maintenance should be
carefully carried out, and safety must be given the
first priority. Messages of safety are indicated with
marks. The safety information contained in the
manual is intended only to supplement safety
codes, insurance requirements, local laws, rules
and regulations.
(3) Messages of safety appear in the manual and on
the machine : All messages of safety are identified
by either word of "DANGER", "WARNING" and
"CAUTION".
1) DANGER- Indicates an imminently hazardous
situation which, if not avoided, will result in
death or serious injury and is represented as
follows:
2) WARNING- Indicates a potentially hazardous

situation which, if not avoided, could result in
death or serious injury and is represented as
follows:
0-2
SAFETY PRECAUTIONS stands, capable of supporting the machine, before
performing any disassembly.
The proper and safe lubrication and maintenance

for this machine, recommended by Manufacturer, Do not operate this machine unless you have
are outlined in the OPERATOR’S MANUAL for the read and understand the instructions in the OP-
machine. ERATOR’S MANUAL. Improper machine opera-
Improper performance of lubrication or mainte- tion is dangerous and could result in injury or
nance procedures are dangerous and could result death.
in injury or death. Read and understand the MAN-
(6) Relieve all pressure in air, oil or water systems be-
UAL before performing any lubrication or mainte-
fore any lines, fittings or related items are discon-
nance.
nected or removed. Always make sure all raised
The serviceman or mechanic may be unfamiliar with components are blocked correctly and be alert for
many of the systems on this machine. This makes it possible pressure when disconnecting any device
important to use caution when performing service work. from a system that utilizes pressure.
A knowledge of the system and or components is im- (7) Lower the bucket, dozer, or other attachments to
portant before the removal or disassembly of any com- the ground before performing any work on the ma-
ponent. chine. If this cannot be done, make sure the bucket,
Because of the size of some of the machine compo- dozer, ripper or other attachment is blocked correct-
nents, the serviceman or mechanic should check the ly to prevent it from dropping unexpectedly.
weights noted in this manual. Use proper lifting proce- (8) Use steps and grab handles when mounting or dis-
dures when removing any components. Weight of com- mounting a machine. Clean any mud or debris from
ponents table is shown in the section ; steps, walkways or work platforms before using.
SPECIFICATIONS. Always face to the machine when using steps, lad-
The following is a list of basic precautions that must al- ders and walkways. When it is not possible to use
ways be observed. the designed access system, provide ladders, scaf-
folds, or work platforms to perform safe repair oper-
(1) Read and understand all Warning plates and decal
ations.
on the machine before Operating, Maintaining or
Repairing this machine. (9) To avoid back injury, use a hoist when lifting com-
ponents which weigh 20kg (45lbs) or more. Make
(2) Always wear protective glasses and protective
sure all chains, hooks, slings, etc., are in good con-
shoes when working around machines. In particu-
dition and are the correct capacity. Be sure hooks
lar, wear protective glasses when using hammers,
are positioned correctly. Lifting eyes are not to be
punches or drifts on any part of the machine or at-
side loaded during a lifting operation.
tachments. Use welders gloves, hood/goggles,
apron and the protective clothing appropriate to the (10)To avoid burns, be alert for hot parts on machines
welding job being performed. Do not wear loose fit- which have just been stopped and hot fluids in
ting or torn clothing. Remove all rings from fingers, lines, tubes and compartments.
loose jewelry, confine long hair and loose clothing (11)Be careful when removing cover plates. Gradually
before working on this machinery. back off the last two capscrews or nuts located at
(3) Disconnect the battery and hang a "Do Not Oper- opposite ends of the cover or device and carefully
ate" tag in the Operators Compartment. Remove ig- pry cover loose to relieve any spring or other pres-
nition keys. sure, before removing the last two capscrews or
nuts completely.
(4) If possible, make all repairs with the machine
parked on a firm level surface. Block the machine (12)Be careful when removing filler caps, breathers and
so it does not roll while working on or under the ma- plugs on the machine. Hold a rag over the cap or
chine. Hang a "Do Not Operate" tag in the Opera- plug to prevent being sprayed or splashed by liq-
tors Compartment. uids under pressure. The danger is even greater if
the machine has just been stopped because fluids
(5) Do not work on any machine that is supported only
can be hot.
by lift, jacks or a hoist. Always use blocks or jack
0-3
(13)Always use the proper tools that are in good condi- (21)Do not operate a machine if any rotating part is
tion and that are suited for the job at hand. Be sure damaged or contacts any other part during opera-
you understand how to use them before performing tion. Any high speed rotating component that has
any service work. been damaged or altered should be checked for
(14)Reinstall all fasteners with the same part number. balance before reusing.
Do not use a lesser quality fastener if replacements (22)Be careful when servicing or separating the tracks
are necessary. (crawlers). Chips can fly when removing or install-
(15)Repairs which require welding should be per- ing a track (crawlers) pin. Wear safety glasses and
formed only with the benefit of the appropriate ref- long sleeve protective clothing. Tracks (crawlers)
erence information and by personnel adequately can unroll very quickly when separated. Keep away
trained and knowledgeable in welding procedures. from front and rear of machine. The machine can
Determine type of metal being welded and select move unexpectedly when both tracks (crawlers)
correct welding procedure and electrodes, rods or are disengaged from the sprockets. Block the ma-
wire to provide a weld metal strength equivalent at chine to prevent it from moving.
least to that of the parent metal. Make sure to dis-
connect battery before any welding procedures are
attempted.
(16)Do not damage wiring during removal operations.
Reinstall the wiring so it is not damaged nor will be
damaged in operation of the machine by contacting
sharp corners, or by rubbing against some object or
hot surface. Do not connect wiring to a line contain-
ing fluid.
(17)Be sure all protective devices including guards and
shields are properly installed and functioning cor-
rectly before starting a repair. If a guard or shield
must be removed to perform the repair work, use
extra caution and replace the guard or shield after
repair is completed.
(18)The maintenance and repair work while holding the
bucket raised is dangerous due to the possibility of
a falling attachment. Don’t fail to lower the attach-
ment and place the bucket to the ground before
starting the work.
(19)Loose or damaged fuel, lubricant and hydraulic
lines, tubes and hoses can cause fires. Do not bend
or strike high pressure lines or install ones which
have been bent or damaged. Inspect lines, tubes
and hoses carefully. Do not check for leaks with
your hands. Very small (pinhole) leaks can result in
a high velocity oil stream that will be invisible close
to the hose. This oil can penetrate the skin and
cause personal injury. Use card-board or paper to
locate pinhole leaks.
(20)Tighten connections to the correct torque. Make
sure that all heat shields, clamps and guards are in-
stalled correctly to avoid excessive heat, vibration
or rubbing against other parts during operation.
Shields that protect against oil spray onto hot ex-
haust components in event of a line, tube or seal
failure must be installed correctly.
0-4
AUS INDEX SK70SR-2
Book Code No. Index
Title 1
Distribution Year–Month No. 33 25
MAINTENANCE SPECIFICATIONS
S5YN0129E01
2010-10
OUTLINE 1
S5YT0215E01
2010-10
SPECIFICATIONS 2
S5YT0315E01
ATTACHMENT DIMENSIONS 3
2010-10 34 2
S5YT1112E01
TOOLS 11
2010-10
S5YT1215E01 STANDARD MAINTENANCE
2010-10
12
TIME SCHEDULE
S5YT1315E01 MAINTENANCE STANDARD
2010-10
13 3
AND TEST PROCEDURE
51 11
S5LF2114E01
MECHATRO CONTROLLER 21
2010-10
S5YT2215E01
2010-10
HYDRAULIC SYSTEM 22
S5YT2315E01
SYSTEM
2010-10
ELECTRIC SYSTEM 23
12
S5YT2415E01
2010-10
COMPONENTS SYSTEM 24
S5LF2514E01
2010-10
AIR-CONDITIONER SYSTEM 25
_
S5YN3129E01 DISASSEMBLING 21 13
DISASSEMBLING
2010-10 & ASSEMBLING

31
S5YT3215E01
ATTACHMENT 32
2010-10
S5YT3315E01
2010-10
UPPER STRUCTURE 33
S5YT3415E01
TRAVEL SYSTEM 34 46 22
2010-10
E / G TROUBLESHOOTING
S5YT4609E01
2010-10
BY ERROR CODES 46
S5LF4712E01
2010-10
BY TROUBLE 47
_ 23
47 31
_
S5YT5112E01
ENGINE 51
2010-10
_
32 24
_
YT06-18444~ APPLICABLE MACHINES
0-5
NOTE:
This Manual is prepared as a technical material in This Manual may be properly revised due to the im-
which the information necessary for the maintenance provement of products, modification of specifications,
and repairing services of our hydraulic excavators are etc. And there are cases where the system on actual
collected, and is categorized into 7 Chapters, Specifica- machine and a part of the contents of this manual may
tion, Maintenance, System, Disassembly, Trouble- differ due to the variations of specification by countries.
shooting, Engine, and Installation Procedures for For the section in which the description is hardly under-
Optional Attachment. stood, contact our distributor.
• The Chapter "Specification" describes the specifi- The number is assigned to every part handled in this
cations for entire machine and material, which are Manual on account of the description, but the parts,
instructive for replacement and repairing of attach- which cannot be supplied as service parts are con-
ments. tained. Therefore, the order must be placed with re-
spective formal number with due confirmation on the
• The Chapter "Maintenance" describes the material,
Parts Manual for applicable machine.
which is helpful for maintenance service and adjust-
ments for entire machine.
• The Chapter "System" describes the operating sys-
tem like hydraulic system, electric system, compo-
nents, and so on.
• The Chapter "Disassembly" describes the removal
and installing of assembly mounted on the upper
structure and undercarriage, and the assembling
and disassembling of the associated hydraulic
equipment.
• The Chapter "Troubleshooting" describes how to
find the fault equipment.
• The Chapter "Engine" describes the engines mak-
ing use of the "Maintenance Manual" provided by
the suppliers.
• The Chapter "Installation Procedures for Optional
Attachment" describes the supplements added on
request as required.
0-6
［1. OUTLINE］
１
1. OUTLINE
TABLE OF CONTENTS
1.1 GENERAL PRECAUTIONS FOR MAKING REPAIRS ……………………………………………………1-3

1.1.1 PREPARATION BEFORE DISASSEMBLING …………………………………………………………1-3
1.1.2 SAFETY WHEN DISASSEMBLING AND ASSEMBLING ……………………………………………1-3
1.1.3 DISASSEMBLING AND ASSEMBLING HYDRAULIC EQUIPMENT ………………………………1-4
1.1.4 ELECTRICAL EQUIPMENT ………………………………………………………………………………1-6
1.1.5 HYDRAULIC PARTS ………………………………………………………………………………………1-7
1.1.6 WELD REPAIR ………………………………………………………………………………………………1-7
1.1.7 ENVIRONMENTAL ISSUES ………………………………………………………………………………1-7
1.2 INTERNATIONAL UNIT SYSTEM ……………………………………………………………………………1-8
Book Code No. S5YN0129E01
1-1
［1. OUTLINE］
Issue Date of Issue Applicable Machines Remarks

SK200-8 : YN12-56001~ S5YN0129E01
First Edition December, 2008
SK210LC-8 : YQ12-08001~ (SE Asia & Oceania)
August, 2009 SK80MSR-2 : LF06-04501~

(Oceania)
SK225SR : YB06-03501~
September, 2009
SK225SRLC : LA06-02501~ (OCE)
November, 2009 SK850LC : LY02-00151~

(SE Asia)
SK140LC-8 : YP09-T0101~
February, 2010 SK130-8 : LP09-T0101~
(TKCM)
SK130L-8 : LX07-T0101~
June, 2010 SK80CS-2 : LF06-04501~

(NA)
E80BMSR : LF06-04501~
(NHK)
E70BSR : YT06-18001~
(NHK-EUR)
SK70SR-2 : YT06-18001~
(NA)
July, 2010 E135BSRLC : YH06-08001~

(NHK-EUR)
SK140SRLC : YH06-08001~
(NA)
SK460-8 : LS11-02501~
August, 2010 SE Asia & India
SK480LC-8 : YS11-02001~
(HS Engine)
E235BSR(N)LC : YU06-03001~
(NHK-EUR)
SK235SRLC-2 : YU06-03001~
(NA)
E225BSR : YB06-03501~
E225BSRLC : LA06-02501~ (NHK-EUR)
SK215SRLC : LA06-02501~
(NA)
September, 2010 E385CLC : YC

(NHK)
SK350LC-9 : YC
(NA)
SK330-8 : LC11-T0101~
SK350LC-8 : YC11-T0101~ TKCM (HS Engine)
SK350LC-8 : YC11-T0101~
(TKCM)
October, 2010 SK80MSR-2 : LF06-04547~

(AUS)
SK70SR-2 : YT06-18444~
(AUS)
1-2
［1. OUTLINE］
1.1 GENERAL PRECAUTIONS FOR MAKING REPAIRS
１
1.1.1 PREPARATION BEFORE DISASSEMBLING
(1) Knowledge of operating procedure

Read Operator's Manual carefully to understand the operating procedure.
(2) Cleaning machines

Clean machines of soil, mud, and dust before carrying into the service shop. Carrying a soiled
machine into the service shop, causes making less efficient work and damage of parts.
(3) Inspecting machines

Confirm the disassembling section before starting work, determine the disassembly procedure taking the
conditions in work shop into account, and request to procure necessary parts in advance.
(4) Recording
Record the following items to keep contact and prevent malfunction from recurring.
1. Inspecting date, place

2. Model name, Serial number and Record on hour meter
3. Trouble condition, place, cause
4. Visible oil leak, water leak and damage
5. Clogging of filters, oil level, oil quality, oil contamination and looseness.
6. Examine the problems on the basis of monthly operation rate with the last inspection date and
records on hour meter.
(5) Arrangement and cleaning in service shop

1. Tools required for repair work.
2. Prepare the places to put the disassembled parts.
3. Prepare oil pans for leaking oil, etc.
1.1.2 SAFETY WHEN DISASSEMBLING AND ASSEMBLING
(1) Safety
1. Wear appropriate clothing, safety shoes, safety helmet, goggles, and clothes with long sleeves.
2. Attach "Don't operate" tag to control lever, and begin a meeting before starting the work.
3. Before starting inspection and maintenance stop the engine.
4. Confirm the position of first-aid kit and fire extinguisher, and also where to make contact for
emergency measure and ambulance to prepare for accidents and fire.
5. Choose a hard, level and safe place, and put attachment on the ground without fail.
6. Use hoist, etc. to remove parts of heavy weight (23kg [50 lb] or more).
7. Use proper tools, and change or repair defective tools.
8. Machine and attachment required to work in the lifting condition should be supported with
supports or blocks securely.
1-3
［1. OUTLINE］
1.1.3 DISASSEMBLING AND ASSEMBLING HYDRAULIC EQUIPMENT
(1) Removing hydraulic equipment assy

1. Before removing pipes, release the pressure of hydraulic oil tank, or open the cover on the return
side to tank, and take out the filter.
2. Drain the oil in the removed pipes into pan to prevent the oil from spilling on the ground.
3. Pipes with plugs or caps to prevent oil leaking, entry of dust, etc.
4. Clean the outside surface of equipment, etc. before disassembling, and drain hydraulic oil and gear
oil before putting them on working bench.
(2) Disassembling hydraulic equipment

1. Since performance and function of hydraulic equipment after disassembly and assembly results in
immunity from responsibility on the manufacture's side, disassembly, assembly and modification
without permission are strictly prohibited.
2. If it is unavoidably necessary to disassemble and modify, it should be carried out by experts or
personnel qualified through service training.
3. Make match mark on parts for reassembling.
4. Before disassembling, read Disassembling Instruction in advance, and determine if the
disassembly and assembly are permitted or not.
5. For parts which are required to use jig and tools, don't fail to use the specified jig and tools.
6. For parts which can not be removed in the specified procedure, never force removal. First check
for the cause.
7. The removed parts should be put in order and tagged so as to install on proper places without
confusion.
8. For common parts, pay attention to the quantity and places.
(3) Inspecting parts

1. Check that the disassembled parts are free from adherence, interference and uneven working face.
2. Measure the wear of parts and clearance, and record the measured values.
3. If an abnormality is detected, repair or replace the parts.
(4) Reassembling hydraulic equipment

1. During the parts cleaning, ventilate the room.
2. Before assembly, clean parts roughly first, and then completely.
3. Remove adhering oil by compressed air, and apply hydraulic oil or gear oil, and then assemble
them.
4. Replace the removed O-ring, back-up rings and oil seal with new ones, and apply grease oil on
them before assembling.
5. Removes dirt and water on the surface on which liquid sealant are applied, decrease them, and
apply liquid sealant on them.
6. Before assembling, remove rust preventives on new parts.
7. Use special tools to fit bearings, bushing and oil seal.
8. Assemble parts matching to the marks.
9. After completion, check that there is no omission of parts.
1-4
［1. OUTLINE］
(5) Installing hydraulic equipment

1. Confirm hydraulic oil and lubrication oil.
１
2. Air release is required in the following cases ;
a. Change of hydraulic oil
b. Replacement of parts on suction pipe side
c. Removing and attaching hydraulic pump
d. Removing and attaching swing motor
e. Removing and attaching travel motor
f. Removing and attaching hydraulic cylinder
3. For air bleed of hydraulic pump and swing motor, loosen drain plug on the upper part, start
engine, and run in low idling, then bleed air until hydraulic oil is comes out. After completion of
comes, tighten plug securely.
4. For air bleed of travel motor and hydraulic cylinder, starts engine and operate it for 10 minutes
or more at no-load and low speed.
5. Air in pilot circuit can be bleed out by only operating digging, swing and traveling motions
thoroughly.
6. Check hydraulic oil level.
Move attachments to hydraulic oil check position, and check hydraulic oil level of tank. Refill oil if
the oil level is lower than the specified level.
How to check oil level of hydraulic oil tank
If hydraulic oil and lubricating oil are not filled and also air bleed is not performed, the hydraulic
equipment may be damaged.
For cylinder, don't move it to the stroke end at beginning.
1-5
［1. OUTLINE］
1.1.4 ELECTRICAL EQUIPMENT
(1) The disassembly of electrical equipment is not allowed.

(2) Handle equipment with care so as not to drop it or bump it.
(3) Connector should be removed by unlocking while holding the connector.
Never stress in tension to the caulked section by pulling wire.
(4) Check that connector is connected and locked completely.
(5) Engine key off before removing and connecting connector.
(6) Engine key off before touching terminals of starter and alternator.
(7) Remove battery grounding terminal before beginning work close to battery and battery relay with
tools.
(8) Wash machine with care so as not to splash water on electrical equipment and connector.
(9) When water has entered in the waterproofed connector, the removing of water is not easy. So
check the removed waterproofed connector with care to protect it from entry of water. If moisture
adheres on it, dry it completely before connecting.
Battery fluid is dangerous.
The battery fluid is dilute sulfuric acid, and causes scald and loss of eyesight by adhering on eyes,
skin and clothes. When the fluid has adhered on them, take an emergency measure immediately and
see a doctor for medical advice.
-When it has adhered on skin; Wash with soap and water.
-When it has got in eyes; Wash in water for 10 minutes or more immediately.
-When it has spilled out in large quantity; Use sodium bicarbonate to neutralize, or wash away with
water.
-When it was swallowed; Drink milk or water.
-When it has adhered on clothes; Wash it immediately.
1-6
［1. OUTLINE］
1.1.5 HYDRAULIC PARTS
１
(1) O-ring
・ Check that O-ring is free from flaw and has elasticity before fitting.
・ Even if the size of O-ring is equal, the usage differs, for example in dynamic and static sections,
the rubber hardness also differs according to the pressure force, and also the quality differs
depending on the materials to be seated. So, choose proper O-ring.
・ Fit O-ring so as to be free from distortion and bend.
・ Floating seal should be put in pairs.
(2) Flexible hose (F hose)

・ Even if the connector and length of hose are the same, the parts differ according to the
withstanding pressure. Use proper parts.
・ Tighten it to the specified torque, and check that it is free from twist, over tension, interference,
and oil leak.
1.1.6 WELD REPAIR

(1) The weld repair should be carried out by qualified personnel in the specified procedure after
disconnecting the grounding cable of battery. If the grounding cable is not disconnected, the
electrical equipment may be damaged.
(2) Remove parts which may cause fire due to the entry of spark beforehand.
(3) Repair attachments which are damaged, giving particular attention to the plated section of piston
rod to protect it from sparks, and don't fail to cover the section with flame-proof clothes.
1.1.7 ENVIRONMENTAL ISSUES

(1) Engine should be started and operated in the place where air can be sufficiently ventilated.
(2) Waste disposal
The following parts follows the regulation.
Waste oil, waste container and battery
(3) Precautions for handling hydraulic oil
Hydraulic oil may cause inflammation of eyes.
Wear goggles to protect eyes on handling it.
-When it has got in eyes ;
Wash eyes with water until the stimulus is gone.
-When it was swallowed ;
Don't force him to vomit it, but immediately receive medical treatment.
-When it has adhered on skin ;
Wash with soap and water.
(4) Others
For spare parts, grease and oil, use KOBELCO genuine ones.
1-7
［1. OUTLINE］
1.2 INTERNATIONAL UNIT SYSTEM
Introduction
Although this manual uses the SI units system.
Outline of SI units system is described here.
Given hereinunder are an excerpt of the units
that are related to this manual :
1. Etymology of SI Units
English : International System of units
2. Construction of SI Unit System
1-8
［1. OUTLINE］
1-9
［1. OUTLINE］
1-10
［2. SPECIFICATIONS］
２
2. SPECIFICATIONS
TABLE OF CONTENTS
2.1 NAME OF COMPONENTS ……………………………………………………………………………………2-3

2.2 GENERAL DIMENSIONS ………………………………………………………………………………………2-4
2.2.1 1.71m (5ft-7in) ARM + 0.28m3 (0.37cu-yd) BUCKET …………………………………………………2-4
2.3 WEIGHT OF COMPONENTS …………………………………………………………………………………2-5
2.4 TRANSPOTATION ………………………………………………………………………………………………2-7
2.4.1 OVERALL DIMENSIONS OF MACHINE ON A TRUCK ……………………………………………2-7
2.4.2 DIMENSIONS OF ATTACHMENT ………………………………………………………………………2-8
2.5 SPECIFICATIONS AND PERFORMANCE ……………………………………………………………………2-10
2.5.1 SPEED AND CLIMBING CAPABILITY …………………………………………………………………2-10
2.5.2 ENGINE ………………………………………………………………………………………………………2-10
2.5.3 HYDRAULIC COMPONENTS ……………………………………………………………………………2-10
2.5.4 WEIGHT ………………………………………………………………………………………………………2-10
2.6 TYPE OF CRAWLER ……………………………………………………………………………………………2-11
2.7 TYPE OF BUCKET ………………………………………………………………………………………………2-12
2.8 COMBINATIONS OF ATTACHMENT …………………………………………………………………………2-13
2.9 ENGINE SPECIFICATION ………………………………………………………………………………………2-14
2.9.1 SPECIFICATIONS …………………………………………………………………………………………2-14
2.9.2 ENGINE CHARACTERISTIC CURVE (ISUZU AU-4LE2X) …………………………………………2-15
Book Code No. S5YT0215E01
2-1

S5YT0215E01
First Edition October, 2010 SK70SR-2 : YT06-18444~
(AUS)
2-2
2.1 NAME OF COMPONENTS
2-3
2.2 GENERAL DIMENSIONS
2.2.1 1.71m (5ft-7in) ARM + 0.28m3 (0.37cu-yd) BUCKET
Dimensions marked * do not include the height of the shoe lug.
2-4
2.3 WEIGHT OF COMPONENTS
Unit: kg (lbs)
1.71M (5ft-7in) Arm
Item / Model
+450mm (17.7in shoe)
Machine complete 7,720 (17,020)
1. Upper frame assy (including the following :) 3,770 (8,310)
２
1.1 Counterweight 843 (1,860)
1.2 Cab 380 (838)
1.3 Engine *189 (417)
1.4 Hydraulic oil tank *69 (152)
1.5 Fuel tank *65 (143)
1.6 Slewing motor (including reduction unit) 67 (150)
1.7 Control valve 105 (232)
1.8 Boom cylinder *91 (201)
1.9 Pin (2pcs. for mounting boom) 11 (24)
1.10 Pump 41 (90)
1.11 Radiator *55 (121)
2. Lower frame assy (including the following :) 2,760 (6,090)
2.1 Slewing bearing 105 (232)
2.2 Travel motor (including reduction unit) 90 (198) X 2
2.3 Upper roller 5 (11) X 2
2.4 Lower roller 14 (31) X 10
2.5 Front idler 45 (99) X 2
2.6 Idler adjuster 29 (64) X 2
2.7 Sprocket 29 (64) X 2
2.8 Swivel joint *28 (62)
2.9 Dozer blade 326 (719)
2.10 Dozer blade cylinders *51 (112)
2.11 Track link with 450 mm (17.7 in) shoes assy 421 (928) X 2
Track link with 600 mm (23.6 in) shoes assy 532 (1,170) X 2
2.11.1 Track link assy 155 (340) X 2
3. Attachment
{3.84 m (12 ft-7 in) Boom+1.71 m (7 ft-0 in) Arm+0.28 m3 (0.29 cuoyd) Bucket} 1,190 (2,624)
3.1 Bucket assy 206 (454)
3.2 Arm assy (including the following :) 318 (701)
3.2.1 Arm 203 (448)
3.2.2 Bucket cylinder *48 (106)
3.2.3 Idler link 9 (20) X 2
3.2.4 Bucket link 23 (51)
3.2.5 Pin (2 pcs. for mounting bucket cylinder / 2 pcs. for mounting bucket) 19 (42)
3.3 Boom assy (including the following :) 662 (1,460)
3.3.1 Boom 452 (997)
3.3.2 Arm cylinder *68 (150)
3.3.3 Pin (Mounting arm, Mounting arm cylinder) 30 (66)
4. Lubricant and water (including the following :) 158 (348)
4.1 Hydraulic oil 45 (99)
4.2 Engine oil 5 (11)
4.3 Fuel 103 (227)
4.4 Water 5 (11)
2-5
Numerical values marked * indicate the dry weight.
2-6
2.4 TRANSPOTATION
2.4.1 OVERALL DIMENSIONS OF MACHINE ON A TRUCK

(1) 3.84m (12ft-7in) Boom+2.84m (9ft-4in) Arm+0.28m3 (0.37cu-yd) Bucket
2.13 M (7 ft-0 in) Arm 1.71 M (5 ft-7 in) Arm
Item / Type
+ 450mm (17.7 in) shoes + 450 mm (17.7 in) shoes
２
Width : mm (ft-in) 2,320 (7'7") 2,320 (7'7")
Weight: kg (lbs) 7,750 (17,090) 7,720 (17,020)
When the 2.13 m (7'0") arm equipped machine is transported, remove the bucket as shown in the
above figure to limit the overall height of the machine within 3.8 m.
2-7
2.4.2 DIMENSIONS OF ATTACHMENT

(1) BOOM
Item / Type 3.84m (12ft-7in) Boom
Length X Height X Width 4 X 1.45 X 0.36
L X H X W: m (ft-in) (13'1" X 4'9" X 1'2")
Weight: kg (lbs) 530 (1,170)
(2) ARM AND BUCKET

2.13m (7ft-0in) Arm+ 1.71m (5ft-7in) Arm+
Item / Type
0.22m3 (0.29 cu-yd) Bucket 0.28m3 (0.37 cu-yd) Bucket
Length X Height X Width 3.63 X 0.71 X 0.65 3.21 X 0.73 X 0.75
L X H X W: m (ft-in) (11'11" X 2'4" X 2'2") (10'6" X 2'5" X 2'6")
Weight: kg (lbs) 570 (1,260) 530 (1,170)
(3) Arm
Item / Type 2.13m (7ft-0in) Arm 1.71m (5ft-7in) Arm
Length X Height X Width 2.66 X 0.58 X 0.21 2.24 X 0.58 X 0.21
L X H X W: m (ft-in) (8'8" X 1'10" X 8.3") (7'4" X 1'10" X 8.3")
Weight: kg (lbs) 300 (660) 260 (570)
2-8
(4) Bucket
Type Hoe bucket
Length X Height X Width 1.10 X 0.60 X 0.40 0.98 X 0.89 X 0.48 0.98 X 0.89 X 0.55
L X H X W: m (ft-in) (3'7" X 1'12" X 1'4") (3'3" X 2'11" X 1'7") (3'3" X 2'11" X 1'10")
Weight: kg (lbs) 150 (330) 150 (330) 170 (380)
3
Bucket capacity: m (cu-yd) 0.11 (0.14) 0.14 (0.18) 0.18 (0.23)
２
Type Hoe bucket
Length X Height X Width 0.98 X 0.89 X 0.65 0.98 X 0.89 X 0.75 0.98 X 0.89 X 0.85
L X H X W: m (ft-in) (3'3" X 2'11 X 2'2") (3'3" X 2'11 X 2'6") (3'3" X 2'11 X 2'9")
Weight: kg (lbs) 190 (420) 210 (460) 220 (490)
3
Bucket capacity: m (cu-yd) 0.22 (0.29) 0.28 (0.37) STD 0.35 (0.45)
(5) Dozer
Item / Type Dozer
Length X Height X Width 1.43 X 0.45 X 2.32
L X H X W: m (ft-in) (4'8" X 1'6" X 7'7")
Weight: kg (lbs) 330 (730)
2-9
2.5 SPECIFICATIONS AND PERFORMANCE
2.5.1 SPEED AND CLIMBING CAPABILITY
Item / Model SK70SR-2

Swing speed : min-1 {rpm} 11.5 {11.5}
Travel speed (1-speed/2-speed) : km/h 2.8 / 5.3
Gradeability : % (degree) 70 (35)
2.5.2 ENGINE
Engine model ISUZU AU-4LE2X

Water-cooled, 4-cycle, direct injection type diesel engine with
Type
intercooler turbo-charger
Number of cylinders-BoreXStroke 4-85 mm X 96 mm (3.35 in X 3.78 in)
Total displacement 2,179 cc (133 cu-in)
net 41 kW / 2,200 min-1 (56 PS / 2,200 rpm) (ISO 9249)
Rated output / Engine speed
net 200 N-m (148 ft-lbs) / 1,600 min-1 (ISO 9249)
Maximum torque / Engine speed
Starter 24 V / 3.2 kW
Alternator 24 V / 0.72 kW
2.5.3 HYDRAULIC COMPONENTS
Hydraulic pump Variable displacement axial piston + gear pump

Hydraulic motor (swing) Axial piston motor
Hydraulic motor (travel) 2-speed axial piston motor
Control valve 8-spool control valve
Cylinder (Boom, arm, Bucket and Dozer) Double action cylinder
Oil cooler Air-cooled type
2.5.4 WEIGHT
Unit : kg (lbs)
With Dozer
Fully equipped weight 7,720 (17,020)
Upper structure 3,770 (8,310)
Lower machinery
2,760 (6,090)
(With 450 mm (17.7 in) grouser shoe)
Attachment
[Boom + 1.71m (5ft-7in) Arm 1,190 (2,620)
+ 0.28m3 (0.37 cu-yd) bucket]
2-10
2.6 TYPE OF CRAWLER
Use grouser shoes 600 mm (23.6 in) or 450 mm (17.7 in) on rough ground (areas covered with
rocks and gravel). If you drive or excavate with other shoes, this may cause shoe bending, shoe bolt
looseness, and track assembly (link, roller, etc.) damage.
2-11
2.7 TYPE OF BUCKET
2-12
2.8 COMBINATIONS OF ATTACHMENT
2-13
2.9 ENGINE SPECIFICATION
2.9.1 SPECIFICATIONS
Applicable machine SK70SR-2

Engine model ISUZU AU-4LE2X
Water-cooled, 4-cycle, direct injection type diesel engine with inter
Type
cooler turbo-charger
Number of cylinder-Bore X Stroke 4-85 mm (3.35 in) X 96 mm (3.78 in)
Total displacement 2,179 cc (133 cu-in)
Compression ratio 18.3
-1
Rated out put net 41 kW / 2,200 min (56 PS / 2,200 rpm) (ISO 9249)
Maximum torque net 200 N-m (148 ft-lbs) / 1,600 min-1 (ISO 9249)
High idling 2,420 ± 30 min-1 (rpm)
Low idling 1,050 min-1 (rpm)
Injection valve opening pressure
16.7 MPa (2,420 psi) / 25.0 MPa (3,630 psi)
First stage / Second stage
Thermostat action Start 82 degC (180 degF) / Full open 95 degC (203 degF)
Firing order 1-3-4-2
Compression pressure 3.04 MPa (441 psi) at 250 min-1 (rpm)
Fuel injection timing 3 degrees before top dead point
Valve clearance Open Close
0.4 mm (0.016" ) 15 deg. before top 29 deg. after bottom
Intake valve
Valve clearance in cold condition dead point dead point
0.4 mm (0.016" ) 40 deg. before top 16 deg. after top
Exhaust valve
in cold condition dead point dead point
Starter capacity 3.2 kW X 24 V
Generator capacity (Alternator) 0.72 kW X 24 V
450 dia. (17.7 in) suction type seven fans
Cooling fan drive method
V-belt drive, pulley ratio Crank / Fan=1.03
Full level Max: 11.0 L (2.9 gal), Min: 8.0 L (2.1 gal)
Engine oil quantity
Oil pan only Max: 10.3 L (2.7 gal), Min: 7.3L (1.9 gal)
Dry weight 199 kg (439 lbs)
Fuel consumption ratio 225 g / kw-h (165 g / PS-h)
Allowable inclination Front / Rear and Right / Left : 35 degrees
Dimension (L X W X H) 739 mm X 527 mm X 754 mm (29 in x 21 in X 30 in)
Rotating direction Counterclockwise seeing from flywheel side
2-14
2.9.2 ENGINE CHARACTERISTIC CURVE (ISUZU AU-4LE2X)

Condition to be measured : Without fan
2-15
2-16
［3. ATTACHMENT DIMENSIONS］
3. ATTACHMENT DIMENSIONS
TABLE OF CONTENTS
３
3.1 BOOM ………………………………………………………………………………………………………………3-3
3.1.1 BOOM DIMENSIONAL DRAWING ………………………………………………………………………3-3
3.1.2 BOOM MAINTENANCE STANDARD ……………………………………………………………………3-4
3.2 ARM ………………………………………………………………………………………………………………3-6
3.2.1 ARM DIMENSIONAL DRAWING …………………………………………………………………………3-6
3.2.2 ARM MAINTENANCE STANDARD ………………………………………………………………………3-8
3.3 BUCKET……………………………………………………………………………………………………………3-10
3.3.1 BUCKET DIMENSIONAL DRAWING ……………………………………………………………………3-10
3.3.2 BUCKET DIMENSIONAL TABLE …………………………………………………………………………3-11
3.3.3 LUG SECTION DIMENSIONAL DRAWING ……………………………………………………………3-12
3.3.4 BOSS SECTION DIMENSIONAL DRAWING …………………………………………………………3-13
3.4 DOZER ……………………………………………………………………………………………………………3-14
3.4.1 DOZER DIMENSIONAL DRAWING………………………………………………………………………3-14
3.4.2 DOZER MAINTENANCE STANDARD……………………………………………………………………3-15
3-1

S5YT0315E01
(AUS)
3-2
3.1 BOOM
3.1.1 BOOM DIMENSIONAL DRAWING
３
Boom Dimensional Drawings
STD
3.84M (12ft-7in) BOOM
YT02B00083P1
No. NAME DIMENSIONS: mm (ft-in)
A Boom length 3,840 (12'7")
B Boom foot width 360 (14.2")
C Boom end inner width 215 (8.46")
D Boom end outer width 303 (11.9")
E Height of boom cylinder rod pin 806 (31.7")
F Height of arm cylinder (head side) pin 1,074 (3'6")
G Distance between pins of boss R1,858.5 (6'1")
H Distance between pins of bracket R1,726.5 (5'8")
I Arm cylinder (head side) inner width 100 (3.94")
J Inner width of bracket on the boom cylinder (rod side) mounting section 100 (3.94")
d1 Boom foot pin dia. 60 dia. (2.36")
d2 Boom cylinder (rod side) pin dia. 70 dia. (2.76")
d3 Pin dia. of boom end. 60 dia. (2.36")
d4 Arm cylinder (head side) pin dia. 60 dia. (2.36")
3-3
3.1.2 BOOM MAINTENANCE STANDARD

(1) Clearance of pin and bushing on boom section
Clearance of pin and bushing on boom section
3-4
(2) Clearance in thrust direction on the boom cylinder installation section
３
Clearance in thrust direction on the boom cylinder installation section
3-5
3.2 ARM
3.2.1 ARM DIMENSIONAL DRAWING
Arm dimensional drawing
3-6
Dimension Dimension
2.13m 2.13m
Code Item Code Item
(7'0") (7'0")
Arm Arm
2,130 210
C Arm length M Boss width
(7'0") (8.27")
Distance between pins of R515.5 100
D N Bracket inner width
boss and bracket (20.3") (3.94")
ø65 90
D1 I.D of boss O Bracket inner width
(2.56") (3.54")
ø60 436.5
D2 I.D of boss P Link dimension
(2.36") (17.2")
380±0.5
ø75
３
D3 I.D of boss Q Link dimension (14.7"
(2.95")
±0.0197")
Distance between pins of R1,504 Height between pins of 15
E' R
boss and bracket (4'11") boss and center (0.591")
Distance between of R240 ø50
F' d1 Pin dia.
boss and boss (9.45") (1.97")
Height between pins of 405.5 ø50
G d2 Pin dia.
Height between pins of 313 ø60
H d3 Pin dia.
Arm top end width 180 ø60
J d4 Pin dia.
(with bushing) (7.09") (2.36")
162 ø50
K Boss width d5 Pin dia.
(6.38") (1.97")
180
L Arm top end
(7.09")
3-7
3.2.2 ARM MAINTENANCE STANDARD

(1) Clearance of pin and bushing
Clearance of pin and bushing on arm section
3-8
(2) Clearance of arm and cylinder installing sections in thrust direction
３
Clearance of arm and cylinder installing sections in thrust direction
3-9
3.3 BUCKET
3.3.1 BUCKET DIMENSIONAL DRAWING

(1) Hoe bucket
Bucket dimensional drawing
No. NAME No. NAME

A Distance between pin and bracket G Inner width of bucket bottom
B Distance between bucket pin and tooth end H Tooth outer width
C Inner width of bucket top end I Pitch between teeth
D Inner width of lug Io Pitch between teeth
E Inner width of bracket d1 Outer dia. of bushing
F Outer width of side cutter d2 Pin dia.
3-10
3.3.2 BUCKET DIMENSIONAL TABLE

Unit : mm (ft-in)
Type Hoe Bucket
0.28 m3 0.35 m3 0.22 m3 0.18 m3 0.14 m3 0.11 m3
Capacity
(0.37 cu-yd) (0.46 cu-yd) (0.29 cu-yd) (0.24 cu-yd) (0.18 cu-yd) (0.14 cu-yd)
Part No. YT61B00042F1 YT61B00017F1 YT61B00019F1 YT61B00021F1 YT61B00023F1 YT61B00025F2
A 290 (11.4") 290 (11.4") 290 (11.4") 290 (11.4") 290 (11.4") 290 (11.4")
B R1,037 (3'5") R1,037 (3'5") R1,037 (3'5") R1,037 (3'5") R1,037 (3'5") R990 (39")
C 650 (25.6") 750 (29.5") 550 (21.7") 450 (17.7") 412 (16.2") 368 (14.5")
D 238 (9.37") 238 (9.37") 238 (9.37") 238 (9.37") 238 (9.37") 238 (9.37")
E 182 (7.17") 182 (7.17") 182 (7.17") 182 (7.17") 182 (7.17") 182 (7.17")
F 750 (29.5") 850 (33.5") 650 (25.6") 550 (21.7") 480 (18.9") 400 (15.7")
３
G 550 (21.7") 650 (25.6") 450 (17.7") 350 (13.8") 280 (11.0") 318 (12.5")
H 573 (22.6") 666 (26.2") 466 (18.3") 366 (14.4") 296 (11.7") 292 (11.5")
I 191 (7.52") 222 (8.74") 166 (6.54") 183 (7.20") 148 (5.83") 146 (5.75")
Io 191 (7.52") 222 (8.74") 150 (5.91") 183 (7.20") 148 (5.83") 146 (5.75")
d1 ø65 (2.56") ø65 (2.56") ø65 (2.56") ø65 (2.56") ø65 (2.56") ø65 (2.56")
d2 ø50 (1.97") ø50 (1.97") ø50 (1.97") ø50 (1.97") ø50 (1.97") ø50 (1.97")
3-11
3.3.3 LUG SECTION DIMENSIONAL DRAWING
Dimension of lug section
3-12
3.3.4 BOSS SECTION DIMENSIONAL DRAWING
３
Dimension of boss section
3-13
3.4 DOZER
3.4.1 DOZER DIMENSIONAL DRAWING
Dozer dimensional drawing
DIMENSION
DOZER
YT51B00064P2
Code Name OCE
A Blade width 2,320 (7'7")
B Blade height 460 (18.1")
C Distance from dozer attaching pin center to cutting edge end R1,370 (4'6")
D Inner width of dozer attaching bracket 653 (25.7)
E Width of dozer attaching bracket 60 (2.36")
Distance from dozer attaching pin center to attaching pin on dozer cylinder
F R932 (36.7")
head side
G Attaching bracket inner width on dozer cylinder head side 82 (3.23")
d1 Dozer attaching pin dia. ø50 (1.97")
d2 Attaching pin dia. on dozer cylinder head side ø70 (2.76")
3-14
3.4.2 DOZER MAINTENANCE STANDARD
３
Dozer maintenance standard
(1) Clearance of pin and bushing
(2) Clearance in thrust direction on the dozer cylinder installation section
3-15
3-16
［11. TOOLS］
11. TOOLS
TABLE OF CONTENTS
11
11.1 TIGHTENING TORQUES FOR CAPSCREWS AND NUTS ………………………………………………11-3
11.2 SCREW SIZE ……………………………………………………………………………………………………11-5
11.2.1 CAPSCREW (BOLT) ………………………………………………………………………………………11-5
11.2.2 CAPSCREW (SOCKET BOLT) …………………………………………………………………………11-5
11.2.3 SOCKET SET SCREW …………………………………………………………………………………11-5
11.3 TIGHTENING TORQUE FOR HOSE AND FITTING ………………………………………………………11-6
11.3.1 JOINT (O-RING TYPE) …………………………………………………………………………………11-6
11.3.2 HYDRAULIC HOSE (30 DEG. FLARE TYPE) ………………………………………………………11-6
11.3.3 JOINT (ORS TYPE) ………………………………………………………………………………………11-6
11.3.4 SPLIT FLANGE ……………………………………………………………………………………………11-6
11.4 TIGHTENING TORQUES FOR NUTS AND SLEEVES……………………………………………………11-7
11.5 PLUGS ……………………………………………………………………………………………………………11-8
11.5.1 PLUG FOR HYDRAULIC PIPE JOINT ………………………………………………………………11-8
11.5.2 PLUG FOR HYDRAULIC EQUIPMENT ………………………………………………………………11-9
11.6 SPECIAL SPANNER FOR TUBE ……………………………………………………………………………11-11
11.7 SPECIAL TOOLS ………………………………………………………………………………………………11-12
11.8 APPLICATION OF SCREW LOCKING COMPOUND AND SEALING COMPOUND…………………11-13
11.9 SUCTION STOPPER……………………………………………………………………………………………11-14
11.9.1 COMPONENTS ……………………………………………………………………………………………11-14
11.9.2 DIMENSION…………………………………………………………………………………………………11-14
11.9.3 APPLICABLE MODEL ……………………………………………………………………………………11-14
11.10 COUNTER WEIGHT LIFTING JIG …………………………………………………………………………11-15
11.11 BOOM FOOT PIN PULLING TOOLS………………………………………………………………………11-16
11.12 TRANION CYLINDER PIN PULLING TOOLS ……………………………………………………………11-17
11.13 UPPER FRAME LIFTING JIG ………………………………………………………………………………11-18
11.14 ENGINE MOUNTING PEDESTAL …………………………………………………………………………11-19
11.15 TRACK SPRING SET JIG …………………………………………………………………………………11-22
11-1
［11. TOOLS］

S5YT1112E01
First Edition July, 2009 SK70SR-2 : YT06-18001~
(SE Asia & Oceania)
August, 2009 SK80MSR-2 : LF06-04501~

(Oceania)
June, 2010 SK80CS-2 : LF06-04501~

(NA)
E80BMSR : LF06-04501~
(NHK)
E70BSR : YT06-18001~
(NHK-EUR)
SK70SR-2 : YT06-18001~
(NA)
October, 2010 SK80MSR-2 : LF06-04547~

(AUS)
SK70SR-2 : YT06-18444~
(AUS)
11-2
［11. TOOLS］
11.1 TIGHTENING TORQUES FOR CAPSCREWS AND NUTS
Tables Table "Metric coarse thread (Not plated)" and Table "Metric fine thread (Not plated)" indicate
tightening torques applicable to cases where no special note is given.
Overtightening of bolts may result in a twist-off and a fracture under load.
Insufficient tightening may lead to a loosening or loss of bolts. Always tighten bolts to proper torques.
11
Tightening torque for metric coarse threads (not plated)
11-3
［11. TOOLS］
Tightening torques for metric fine threads (not plated)
11-4
［11. TOOLS］
11.2 SCREW SIZE
11.2.1 CAPSCREW (BOLT)
11
11.2.2 CAPSCREW (SOCKET BOLT)
11.2.3 SOCKET SET SCREW
11-5
［11. TOOLS］
11.3 TIGHTENING TORQUE FOR HOSE AND FITTING
11.3.1 JOINT (O-RING TYPE)
11.3.2 HYDRAULIC HOSE (30 DEG. FLARE TYPE)
11.3.3 JOINT (ORS TYPE)
11.3.4 SPLIT FLANGE
11-6
［11. TOOLS］
11.4 TIGHTENING TORQUES FOR NUTS AND SLEEVES
Table below indicates standard tightening torques applicable to cases where no particular note is given.
Overtightening or undertightening of nuts and sleeves in FLARELESS JOINT may develop oil leaks
through pipe connections.
Always tighten nuts and sleeves to proper torques.
11
11-7
［11. TOOLS］
11.5 PLUGS
11.5.1 PLUG FOR HYDRAULIC PIPE JOINT

(1) Cap nut (Joint plug)
(2) Plug (Tube plug)
(3) Nut
11-8
［11. TOOLS］
11.5.2 PLUG FOR HYDRAULIC EQUIPMENT

(1) PF screw
(2) PT screw
11
(3) Plug for(F)flare hose
11-9
［11. TOOLS］
(4) Plug for ORS joints

Male
Female
(5) Plug for half clamp
11-10
［11. TOOLS］
11.6 SPECIAL SPANNER FOR TUBE
11
11-11
［11. TOOLS］
11.7 SPECIAL TOOLS
11-12
［11. TOOLS］
11.8 APPLICATION OF SCREW LOCKING COMPOUND AND

SEALING COMPOUND
(1) For general use
Manufacturer
Service Features
Loctite Three-Bond
#242 1360K Low strength
Screw locking
#262 1374 Middle strength
compound
#271 1305 High strength
Sealing compound #515 1215 Sealing
(2) For specific location

No. Use Manufacturer Name Equivalent Applicable
11
(Manufacturer ; Loctite)
# 1901 Anti-seizure Cylinder
Three-Bond # 1215 gray # 5699 Swing motor
# 1211 white # 5301J Swing motor
# 1303B # 211 Main pump
(Manufacturer ; Three-Bond)
Sealing
Loctite # 222 # 1344N Main pump
compound
1 # 277 # 1307N Pilot valve
&
adhesive (Manufacturer ; Three-Bond)
Loctite Parmatex 98D # 1121 Hydraulic oil tank : Hose
Sumitomo
Chemical Co., Cyano Bond PO-1 Swing bearing : seal
Ltd.
Shell
petroleum Shell Alvania EP2 New Molyknock Grease 2 Swing bearing grease bath
11-13
［11. TOOLS］
11.9 SUCTION STOPPER
11.9.1 COMPONENTS
Components of suction stopper
11.9.2 DIMENSION
Dimension of suction stopper
11.9.3 APPLICABLE MODEL
11-14
［11. TOOLS］
11.10 COUNTER WEIGHT LIFTING JIG
11
Counterweight lifting jig
11-15
［11. TOOLS］
11.11 BOOM FOOT PIN PULLING TOOLS
Slide hammer for boom foot pin
Tool accesories assy YR01T00006F1
11-16
［11. TOOLS］
11.12 TRANION CYLINDER PIN PULLING TOOLS
Tranion cylinder pin pulling tools 11
Tool accesories assy YR01T00005F1
11-17
［11. TOOLS］
11.13 UPPER FRAME LIFTING JIG
Upper frame lifting jig
11-18
［11. TOOLS］
11.14 ENGINE MOUNTING PEDESTAL
11
Engine mounting pedestal
11-19
［11. TOOLS］
Rear housing pedestal (17. PVC plate is proved)
Front oil pan pedestal (140X180X540)
11-20
［11. TOOLS］
Detail of front sandwich bar (70X70X400)
11
Detail of rear sandwich bar (70X70X400)
Woody materials
No. PARTS Q'TY REMARKS
1 Crossbar 2 70 X 70 X 925 0.0093m3
2 Base 2 70 X 70 X 540 0.0053m3
3 Front oil pan pedestal (With notch) 1 140 X 180 X 540 0.0136m3 (With notch)
3
4 Right prevention interference bar 1 50 X 50 X 650 0.0016m
5 Front sandwich bar 1 70 X 70 X 400 0.0020m3 (With notch)
6 Rear housing pedestal 1 95 X 140 X 540 0.0060m3 (With notch)
7 Rear sandwich bar 1 70 X 70 X 400 0.0020m3
8 Left prevention interference bar 1 70 X 70 X 585 0.0029m3
9 Bar for stopper 1 30t X 140 X 540
Bolts, Nails, Wood screws

11 Bolt 4 12 dia. X 255 (Top and bottom counterbore)
12 Bolt 2 12 dia. X 185 (Top and bottom counterbore)
13 Wood screw 21 3.1 dia. X 35 (12 dia. Counter sinking)
14 Coach screw 10 9 dia. X 90 (Top counterbore)
15 Screw nail 20 2.2 dia. X 50~60 (Drive nail at connection points appropriately)
16 Coach screw 2 9 dia. X 90
PVG plates
17 PVG plate 1 5t X 90 X 564 (Wood screw cramp)
18 PVG plate 3 5t X 50 X 130 (Wood screw cramp)
11-21
［11. TOOLS］
11.15 TRACK SPRING SET JIG
Track spring set jig
11-22
［12. STANDARD MAINTENANCE TIME TABLE］
12. STANDARD MAINTENANCE

TIME TABLE
TABLE OF CONTENTS
12.1 STANDARD WORKING TIME TABLE FOR THE MAINTENANCE OF EXCAVATOR ………………12-4
12.2 ENGINE MAINTENANCE SERVICE STANDARD TIME LIST……………………………………………12-14
12
12-1

S5YT1215E01
(AUS)
12-2
PREFACE
(1) Working Conditions
1. Workers:
More than one worker shall be 1st class service technician (having five years or more of field
experience and having received training in the operation).
2. Equipment:
Jigs, tools, apparatuses and testers used in field service work shall be available commercially.
The maintenance plant shall be equipped with a service shop, a crane and inspection
apparatuses necessary for specific self inspection activities.
3. Place:
A flat land where work may be performed and to which a service car or a truck crane is
accessible.
(2) Range of standard maintenance time

1. Standard maintenance time = Direct maintenance time + Preparation time
2. Direct maintenance time: Net time actually spent for maintenance
3. Spare time:
Time needed to move machines for service, prepare safety operations, discuss work, and process
the needs of the body.
12
(3) Extra time (not included in the standard service time)
1. Repair time:
Machining, sheet metal, welding, melt cutting, folding and extracting bolts, servicing parts, and
painting.
2. tems excluded from service time because of uncertainty in time:
Receiving a vehicle into shop, transfer, delivery, inspection on completion, investigation of causes
of faults, diagnosis, and inspection.
3. Indirect time:
Time for; field work, preparation of necessary parts before leaving for work, return for field work,
waiting time because of user's convenience in the field, paper work after returning to shop, and
preparation of bills.
4. Special time: Work at early morning, at midnight and on holidays are to be calculated separately.
5. Separate calculation: The operating time for service cars, trucks with a crane and crane trucks.
(4) Applicable machine for estimation of standard maintenance time

1. Standard machine
2. A well maintained and controlled machine with a standard combination of attachments which is
used in a general environment.
12-3
12.1 STANDARD WORKING TIME TABLE FOR THE

MAINTENANCE OF EXCAVATOR
(1) Standard maintenance time table
1. Units of working time: 6 minutes = 0.1 hour
2. Calculating method of standard maintenance time:
Maintenance time = Working time X Number of workers
(Working time = Maintenance time / Number of workers)
3. When more than one operation is going on:
Add each standard service time. A pure time (readily started) is given except covers easily
removed by hand. Assy works include the following works marked with black dot.
4. O/H: The removing and attaching time is not included.
5. Abbreviations in the table.
A/C : Air conditioner C/V : Control valve O/H : Over haul

ASSY : Assembly Cyl : Cylinder SOL : Solenoid
ATT : Attachment E/G : Engine SW : Switch
BRG : Bearing F hose : Flexible hose V : Valve
(2) Classification of work code

No. GROUP REMARKS
01 Attachment Indicates installing, removing, replacement and overhaul.
02 Cab & Guard
03 Swing frame
04 Travel system
Electric Indicates the installing, removing and replacement of single items.
06
equipments
09 E/G relation Indicates overhaul of the single engine.
(Materials prepared by manufacturer)
(3) Conditions for standard service time of the engine

1. Tools designated by E/G maker are used
2. Genuine parts are changed
3. Correct working procedures are observed.
・ The time required for works specified in this Chapter shows the total time for maintenance.
12-4
01 Attachment
Work to be Unit:
Group Location Unit Remarks
done Hour
00 Bucket relation See 32.1.2
01 Bucket ASSY Detach/attach 1 pc. Include adjustment 0.5
02 -Bucket attaching and detaching Preparation 1 pc. 0.1
position
03 -Bucket attaching pin Detach/attach 1 Include omission of pin 0.1
04 -Bucket drive pin Detach/attach 1 0.1
05 -Bucket sling and movement Preparation 1 pc. 0.1
06 Bucket (single) O/H 1 pc. Not include attaching and 2.0
detaching
07 -Tooth Replace 1 pc. 0.5
08 -Side cutter Replace 1 pc. 1.0
09 -Bushing Replace 1 pc. 0.5
10 Arm relation See 32.1.3
11 Arm ASSY Detach/attach 1 pc. 1.0
12 -Bucket cylinder attaching and Preparation 1 pc. Include omission of pin 0.3
detaching position and piping Include omission of pin
13 -Bucket cylinder rod pin Detach/attach 1 pc. 0.1
14 -Bucket cylinder head pin Detach/attach 1 pc. Include omission of pin 0.1 12
15 -Bucket cylinder assy Detach/attach 1 pc. 0.1
16 -Arm cylinder rod pin Detach/attach 1 pc. 0.1
17 -Boom top pin Detach/attach 1 pc. 0.1
18 -Arm sling and movement Detach/attach 1 pc. 0.1
30 Boom relation See 32.1.4
31 -Boom ASSY Detach/attach 1 pc. 1.0
32 -Boom attaching and detaching position Preparation 1 pc. 0.1
33 -Boom cylinder temporary slinging Preparation 1 pc. 0.1
34 -Boom cylinder rod pin Detach/attach 1 Include omission of pin. 0.1
35 -Boom cylinder piping Detach/attach 1 pc. 0.1
36 -Arm & bucket piping Detach/attach 1 pc. 0.2
37 -Boom assy temporary slinging Detach/attach 1 pc. 0.1
38 -Boom foot pin Detach/attach 1 Include omission of pin 0.2
39 -Boom assy slinging Detach/attach 1 pc. 0.1
40 Arm cylinder attaching and detaching Detach/attach 1 pc. 0.3
41 -Arm cylinder piping Detach/attach 1 pc. 0.1
42 -Arm cylinder head pin Detach/attach 1 Include omission of pin 0.1
43 -Arm cylinder slinging Detach/attach 1 pc. 0.1
50 Boom cylinder attaching and detaching Detach/attach 1 pc. 0.3
51 -Boom cylinder piping Detach/attach 1 0.1
52 -Boom cylinder head pin Detach/attach 1 pc. 0.1
53 -Boom cylinder slinging Detach/attach 1 0.1
60 Bucket cylinder O/H 1 3.0
61 -Pin bushing Preparation 1 Include seal 1.0
70 Arm cylinder O/H 1 3.0
71 -Pin bushing Preparation 1 set Include seal 1.0
75 Boom cylinder O/H 1 3.0
76 -Pin bushing Preparation 1 Include seal 1.0
12-5
02 Cab & Guard

Work to be Unit:
done Hour
10 Cab relation See 33.1.19
11 Cab ASSY Detach/attach 1 pc. 1.4
12 -Front lower glass, floor mat Detach/attach 1 pc. each 0.1
13 -Seat rear cover top, bottom Detach/attach 4 places 0.2
14 -Seat rear cover top, bottom Detach/attach 1 pc. each 0.2
15 -Right side panel (include A/C duct) Detach/attach 3 0.3
16 -Cable and harness (electric) Detach/attach 6 0.2
17 -Cab mounting bolt Detach/attach 8 pcs. 0.2
18 -Cab slinging Detach/attach 3 places 0.2
20 Guard relation See 33.1.4
21 Panel assy (2-1) Detach/attach 1 pc. 0.1
22 Cover assy (2-5) Detach/attach 1 pc. 0.1
25 Guard assy (4-2) Detach/attach 1 pc. 0.1
27 Bonnet (3-2) Detach/attach 1 pc. 0.1
28 Bonnet assy (3-1) Detach/attach 1 pc. 0.1
29 Cover (3-3), (3-4) Detach/attach 1 pc. 0.1
30 Bonnet (3-2) Detach/attach 1 pc. 0.1
31 Left hand cover (5-1) Detach/attach 1 pc. 0.1
32 Right hand cover (5-2) Detach/attach 1 pc. 0.1
33 Bracket (1-5) Detach/attach 1 pc. 0.1
35 Pillar (1-4) Detach/attach 1 pc. 0.1
36 -Guard assy (11) Detach/attach 1 pc. 0.2
40 Cover relation See 33.1.5
41 Cover (1) Detach/attach 1pc. 0.1
50 Counter weight relation See 33.1.11
51 Counter weight ASSY Detach/attach 1 pc. 0.4
52 -Counter weight lifting jig Detach/attach 1 set 0.1
53 -Counter weight temporary slinging Preparation 1 pc. 0.1
54 -Counter weight mounting bolt Detach/attach 1 pc. 0.1
55 -Counter weight slinging Detach/attach 1 pc. 0.1
12-6
03 Swing frame (1/3)

Work to be Unit:
done Hour
10 Intake relation See 33.1.9
11 Air cleaner ASSY Detach/attach 1 pc. 0.3
12 -Hose (5) Detach/attach 1 0.1
13 -Hose (3) Detach/attach 1 0.1
14 -Element Replace 1 0.1
20 Exhaust relation See 33.1.10
21 Muffler ASSY Detach/attach 1 pc. 0.4
22 -U bolt Detach/attach 1 pc. 0.1
23 -Clamp ASSY Detach/attach 1 pc. 0.1
24 -Gasket Replace 1 pc. 0.1
30 Radiator relation See 33.1.12
31 Radiator ASSY Detach/attach 1 pc. 3.2
32 -Coolant (LLC) Replace 1 pc. 0.2
33 --Concentration of coolant Measuring 1 pc. 0.2
34 -A/C condenser Detach/attach 1 pc. 0.2
35 -Stay Detach/attach 1 pc. 0.1
36
37
-Bracket
-Sub tank
Detach/attach
Detach/attach 1
1
pc.
0.2
0.1
12
38 -Fan guard Detach/attach 1 pc. 0.2
39 -Water hose (radiator~E/G) Detach/attach 2 0.4
40 -Radiator mounting bolts removing Detach/attach 1 pc. 0.2
41 -Under cover Detach/attach 1 pc. 0.1
42 -Hydraulic oil tank o suction stopper Detach/attach 1 pc. 0.2
43 -Hydraulic oil piping Detach/attach 1 pc. 0.2
44 -Inter cooler hose (E/G~radiator) Detach/attach 2 0.4
45 -Radiator lifting or hoisting Detach/attach 1 pc. 0.2
46 -Radiator inter cooler core & oil coolter Cleaning 1 pc. 1.0
50 Fuel relation See 33.1.6
51 Fuel tank ASSY Detach/attach 1 pc. 1.1
52 -Fuel Replace 1 pc. 0.2
53 -Hose (water separator side) Detach/attach 2 0.1
54 -Water separator Detach/attach 1 pc. 0.1
55 -Hose (tank side) Detach/attach 1 0.1
56 -Fuel tank installing bolts Detach/attach 1 pc. 0.2
57 -Tank slinging Detach/attach 1 pc. 0.2
Other necessary works Detach/attach 1 pc. Removing and installing 0.2
guard
60 Hydraulic oil tank relation See 33.1.11
61 Hydraulic oil tank ASSY Detach/attach 1 pc. After removing fuel tank ; 2.1
62 -Hydraulic oil tank attaching and Detach/attach 1 pc. 0.1
detaching position
63 -Cover Detach/attach 1 pc. 0.2
64 -Hydraulic oil Replace 1 pc. 0.4
68 -Pilot drain hose Detach/attach 1 pc. 0.2
69 -Pump suction hose Detach/attach 1 0.4
70 -Mounting bolt Detach/attach 1 pc. 0.2
71 -Hydraulic oil tank slinging Detach/attach 1 pc. 0.2
72 -Return filter Replace 1 0.2
73 -Suction filter Cleaning 1 0.2
12-7

Work to be Unit:
done Hour
80 Pump relation See 33.1.8
81 Pump ASSY Detach/attach 1 pc. After removing counter 2.3
weight
82 -Hydraulic oil tank cover Detach/attach 1 pc. 0.3
83 -Strainer & stopper Detach/attach 1 pc. 0.3
84 -Piping Detach/attach 1 set 0.8
85 -Guard Detach/attach 4 pc. 0.4
86 -Pump slinging Detach/attach 1 pc. 0.4
87 -Cleaning Cleaning 1 pc. 0.1
88 -Vent air Adjust 1 pc.
89 Pump ASSY O/H 1 pc. Counter weight 3.0
Other necessary works Detach/attach 1 set 0.4
90 Swing motor unit relation See 33.1.18
91 Swing motor ASSY Detach/attach 1 pc. After removing boom 1.8
93 -Drain hose clamp Detach/attach 1 0.2
95 -Unit slinging Detach/attach 1 pc. 0.3
96 -Cleaning and sealant Cleaning 1 set 0.2
97 -Swing motor O/H 1 pc. 3.0
98 -Swing reduction gear O/H 1 pc. 3.5
100 Swivel joint relation See 33.1.19
101 Swivel joint ASSY Detach/attach 1 After removing boom 1.5
102 -Piping (Top part only) Detach/attach 1 set. 0.3
103 -Stop gap Detach/attach 1 0.1
104 -Cover Detach/attach 1 0.2
105 -Joint & elbow Detach/attach 1 set 0.2
106 -Mounting bolt Detach/attach 1 set 0.2
107 -Swivel joint slinging Detach/attach 1 0.2
108 -Cleaning Cleaning 1 set 0.1
109 Swivel joint O/H 1 set 3.0
Other necessary works Detach/attach 1 set Front attach ASSY 1.5
Detach/attach 1 set Lower piping 0.5
120 Main control valve See 33.1.15
121 Main control valve ASSY Detach/attach 1 pc. 1.5
122 -Attach tag to port name of pipe Preparation 1 pc. 0.5
124 -Bracket mounting bolts Detach/attach 1 pc. 0.1
125 -Valve slinging Detach/attach 1 pc. 0.1
126 Main control valve ASSY O/H 1 set 5.0
Other necessary works Detach/attach 1 set Guard 0.3
12-8

Work to be Unit:
done Hour
140 Engine (E/G) mounting relation See 33.1.13
141 Engine ASSY Detach/attach 1 pc. After removing pump & 1.5
radiator
142 -Harness connector & grounding & Detach/attach 1 pc. 0.2
cable connection
143 -Fuel hose Detach/attach 1 pc. 0.1
144 -Others Detach/attach 1 set 0.4
146 -Engine slinging Detach/attach 1 set 0.2
148 Engine O/H 1 set Reference for engine
(Chapter 51)
Other necessary works Detach/attach 1 set Removing and installing 0.5
guard
Detach/attach 1 set Removing and installing 0.4
Counterweight
12
pump
Detach/attach 1 set Removing and installing air 0.4
cleaner
muffler
radiator
150 Upper frame See 33.1.20
151 Upper frame ASSY Detach/attach 1 pc. After removing swivel joint 1.0
152 -Mounting bolts Detach/attach 1 set 0.3
153 -Upper frame slinging Detach/attach 1 pc. 0.3
155 -Sealant Apply 1 pc. 0.2
Other necessary works Detach/attach 1 set Cab 1.5
Detach/attach 1 set Guard 0.3
Detach/attach 1 set Counterweight 0.4
Detach/attach 1 set Boom 1.0
12-9
04 Travel system
Work to be Unit:
done Hour
00 Travel relation See 34.1.2
01 Track link ASSY Detach/attach One side Include adjustment of 1.0
tension
02 -Track link attaching and detaching Preparation One side 0.1
position
03 -Master pin Detach/attach One side 0.4
04 -Track link extending and winding Detach/attach One side 0.4
05 Shoe plate Replace 1 pc. 0.4
10 Upper roller relation See 34.1.3
11 Upper roller ASSY Detach/attach 1 After removing track link 0.2
12 Upper roller O/H 1 1.0
20 Lower roller relation See 34.1.4
21 Lower roller ASSY Detach/attach 1 0.2
22 Lower roller O/H 1 1.0
30 Front idler relation See 34.1.5
31 Front idler ASSY Detach/attach One side After removing track link 0.5
32 Front idler ASSY slinging Detach/attach One side 0.2
33 Front idler ASSY Detaching One side 0.2
34 Idler ASSY O/H One side 1.0
35 Idler adjuster ASSY O/H One side Replace spring 2.0
36 -Grease cylinder O/H One side 0.5
40 Sprocket See 34.1.6
41 Sprocket Replace One side After removing track link 0.5
50 Travel motor relation See 34.1.7
51 Travel motor ASSY Detach/attach One side After removing track link 1.4
52 -Motor cover Detach/attach One side 0.1
53 -Hydraulic piping Detach/attach One side 0.7
54 -Motor mounting bolts Detach/attach One side 0.4
55 -Motor slinging Detach/attach One side 0.1
56 Motor cleaning Cleaning One side 0.1
57 Travel motor O/H One side 3.0
58 Travel reduction gear O/H One side 3.0
60 Swivel joint relation
61 Pipe on swivel joint travel side Detach/attach 1 pc. 0.5
62 Swivel joint O/H 1 pc. See 33.2.6
70 Swing bearing See 34.1.8
71 Swing bearing ASSY Detach/attach 1 pc. After removing upper frame 0.6
72 Swing bearing mounting bolts Detach/attach 1 set 0.4
73 Swing bearing slinging Detach/attach 1 pc. 0.2
80 Dozer relation
81 Dozer ASSY Detach/attach 1 pc. 0.6
81 -Dozer cylinder piping Detach/attach 1 pc. 0.2
82 -Dozer cylinder slinging Detach/attach 1 0.2
83 Dozer slinging Detach/attach 1 pc. 0.2
84 Dozer Cylinder O/H 1 2.0
12-10
06 Electric equipments (1/3)

Work to be Unit:
done Hour
Controller
C-1 Controller (KPSS) Replace 1 0.2
C-2 Gauge cluster Replace 1 0.2
C-4 Air conditioner Amplifier Replace 1 0.2
C-10 EGR cut controler Replace 1 0.2
Diode
D-1 Diode Replace 1 0.2
D-17 Diode Replace 1 0.2 12
Electric equipments
E-1 Fuse box & relay box Replace 1 Include C1 controller 0.3
removing and installing.
E-2 Alternator Replace 1 Include bonnet assy 1.0
E-3 Hour meter Replace 1 0.2
E-6 Horn (low) Replace 1 0.2
E-7 Tuner AM / FM Replace 1 0.2
E-10 Receiver dryer Replace 1 Include gas sealing 0.3
E-11 Air compressor Replace 1 Include counter weight 0.5
E-12 Battery Replace 2 0.4
E-13 Travel alarm Replace 1 0.2
E-22 DC-DC converter Replace 1 0.2
E-23 12V socket Replace 1 0.2
E-35 Glow Replace 1 0.2
E-65 24V socket Replace 1 0.2
Light
L-1 Boom work light left Replace 1 Bulb 0.2
L-3 Swing flasher (LH) Replace 1 0.2
L-4 Swing flasher (RH) Replace 1 0.2
L-7 CAB work light front 1 Replace 1 0.2
L-8 CAB work light front 2 Replace 1 0.2
12-11

Work to be Unit:
done Hour
Motor
M-1 Starter motor Replace 1 Include counter weight 1.0
M-2 Governor motor Replace 1 Include counter weight 0.5
M-3 Wiper motor Replace 1 0.2
M-4 Washer motor Replace 1 0.2
M-12 Fuel pump Replace 1 0.2
Relay
R-1 Battery relay Replace 1 0.2
R-3 Glow relay Replace 1 0.2
R-4 Safety relay Replace 1 0.1
R-5 Horn relay Replace 1 0.1
R-6 Work light relay Replace 1 0.1
R-8 Travel alarm relay Replace 1 0.1
R-15 Nibbler open relay (OPT) Replace 1 0.1
R-16 Nibbler close relay (OPT) Replace 1 0.1
R-23 Auto idle stop relay 1 Replace 1 0.1
R-24 Auto idle stop relay 2 Replace 1 0.1
R-26 Lever lock relay Replace 1 0.1
R-28 Alternator relay Replace 1 0.1
R-29 Wiper motor relay Replace 1 0.1
R-31 Prevent spark relay Replace 1 0.1
R-32 Window washer motor relay Replace 1 0.1
R-42 Extra (B) relay Replace 1 0.2
R-43 Extra (A) relay Replace 1 0.2
R-49 ERG cut relay Replace 1 0.1
Sensor
SE-1 Pressure sensor (low pressure ; bucket Replace 1 0.2
digging)
SE-2 Pressure sensor (low pressure ; bucket Replace 1 0.2
dump)
SE-3 Pressure sensor (low pressure ; boom Replace 1 0.2
up)
SE-4 Pressure sensor (low pressure ; boom Replace 1 0.2
down)
SE-7 Pressure sensor (low pressure ; arm in) Replace 1 0.2
SE-8 Pressure sensor (low pressure ; arm out) Replace 1 0.2
SE-9 Pressure sensor (low pressure ; travel Replace 1 Include removing installing 0.4
right) guard on cab lower side.
SE-10 Pressure sensor (low pressure ; travel Replace 1 Include removing installing 0.4
left) guard on cab lower side.
SE-13 Engine speed sensor Replace 1 Include guard removing 0.5
and installing.
SE-14 Engine coolant thermo sensor Replace 1 0.2
SE-15 Fuel sensor Replace 1 Include guard removing 0.3
and installing.
SE-16 Accel potentio Replace 1 0.2
12-12

Work to be Unit:
done Hour
SE-24 Press. sensor : boom head (OPT) Replace 1 0.2
SE-25 Press. sensor : boom rod (OPT) Replace 1 0.2
SE-40 Press. sensor : (low pressure ; swing Replace 1 0.2
right)
SE-41 Press. sensor : (low pressure ; swing left) Replace 1 0.2
SE-47 Press. sensor : dozer down Replace 1 0.2
SE-48 Press. sensor : dozer up Replace 1 0.2
SE-53 Pressure sensor : (low pressure ; boom Replace 1 0.2
swing right)
Solenoid
SV-1 Swing parking SOL Replace 1 Include proportional valve 2.0
SV-3 2-speed travel SOL Replace 1 Include proportional valve 2.0
SV-4 Lever lock SOL Replace 1 Include proportional valve 2.0
SV-15 Engine stoop SOL Replace 1 Include proportional valve 2.0
12
SV-37 EGR cut SOL Replace 1 Include proportional valve 2.0
Switch
SW-1 Key switch Replace 1 0.2
SW-4 Swing parking release switch Replace 1 0.2
SW-5 Horn switch right Replace 1 0.2
SW-6 Engine water temperature switch Replace 1 0.2
SW-7 Engine oil pressure switch Replace 1 0.2
SW-8 Clogged air filter switch Replace 1 0.1
SW-10 Horn switch Replace 1 0.2
SW-11 Lever lock switch Replace 1 0.3
SW-13 Travel alarm switch Replace 1 0.2
SW-15 Conflux-single flow select switch Replace 1 0.2
SW-17 Roof wiper switch Replace 1 0.2
SW-19 Wiper interlock switch Replace 1 0.2
SW-26 Cab work light switch Replace 1 0.2
SW-55 Boom deck working light switch Replace 1 0.2
12-13
12.2 ENGINE MAINTENANCE SERVICE STANDARD TIME LIST
This page is left blank because we had not received related information from "Engineering Division".
12-14
［13. MAINTENANCE STANDARD AND TEST PROCEDURE］
13. MAINTENANCE STANDARD AND

TEST PROCEDURE
TABLE OF CONTENTS
13.1 HOW TO USE MAINTENANCE STANDARDS AND PRECAUTIONS …………………………………13-3

13.2 PERFORMANCE INSPECTION STANDARD TABLE ……………………………………………………13-5
13.2.1 STANDARD VALUE TABLE ……………………………………………………………………………13-5
13.3 MEASUREMENT OF ENGINE SPEED ………………………………………………………………………13-7
13.3.1 MEASUREMENT OF ENGINE SPEED ………………………………………………………………13-7
13.4 MEASUREMENT OF HYDRAULIC PRESSURE……………………………………………………………13-8
13.4.1 PREPARING TO MEASURE HYDRAULIC PRESSURE ……………………………………………13-8
13.4.2 PLACE TO INSTALL PRESSURE GAUGE …………………………………………………………13-8
13.4.3 PRESSURE ADJUSTMENT POSITION ………………………………………………………………13-9
13.4.4 PROCEDURE FOR ADJUSTING RELIEF VALVE …………………………………………………13-11
13.5 MEASURING TRAVEL PERFORMANCES …………………………………………………………………13-13
13
13.5.1 TRAVEL SPEED …………………………………………………………………………………………13-13
13.5.2 DEVIATION OF TRAVEL…………………………………………………………………………………13-13
13.5.3 PERFORMANCES OF PARKING BRAKE ……………………………………………………………13-14
13.5.4 DRAIN RATE OF TRAVEL MOTOR …………………………………………………………………13-15
13.6 MEASURING SWING PERFORMANCES……………………………………………………………………13-16
13.6.1 MEASURING SWING PERFORMANCES ……………………………………………………………13-16
13.6.2 PERFORMANCE OF SWING BRAKE …………………………………………………………………13-16
13.6.3 PERFORMANCE OF SWING PARKING BRAKE ……………………………………………………13-17
13.6.4 DRAIN RATE OF SWING MOTOR ……………………………………………………………………13-18
13.7 MEASURING ATTACHMENT OPERATING PERFORMANCES …………………………………………13-19
13.7.1 OPERATING TIME OF CYLINDERS …………………………………………………………………13-19
13.7.2 OIL TIGHTNESS OF CYLINDERS ……………………………………………………………………13-20
13.8 MEASURING PERFORMANCES OF SWING BEARING …………………………………………………13-21
13.9 MECHATRO CONTROLLER …………………………………………………………………………………13-22
13.9.1 ENGINE CONTROL INPUT / OUTPUT ………………………………………………………………13-22
13.9.2 ENGINE CONTROL ………………………………………………………………………………………13-22
13.9.3 ENGINE CONTROL EQUIPMENT………………………………………………………………………13-23
13.9.4 ADJUSTMENT OF MECHATRO CONTROLLER OUTPUT (A ADJUSTMENT) ………………13-24
13-1

S5YT1315E01
(AUS)
13-2
13.1 HOW TO USE MAINTENANCE STANDARDS AND

PRECAUTIONS
(1) Application
1. When the machine is new;
Confirm that the performances are in accordance with standard specifications as compared to the
performance standards.
2. At specific self inspection; (Rule by country)
Use the data for the criterion, for the purpose of correction, adjustment and replacement.
3. When performances are deteriorated;
Determine whether it is caused by a fault or end of service life after long hours of operation, to
be used for safety and economical considerations.
4. When main components are replaced;
For example, use data to restore performances of pumps and others.
(2) Terminology
1. Standard values;
Values to be used to condition or assemble a new machine. Where special notes are not given,
these values represent standard specifications (machine with standard attachments and standard
shoes).
2. Reference values for remedy;
Values at which readjustment is required. In order to ensure performance and safety it is strictly
prohibited to use the machine over the specified values.
3. Service limit;
This is the limit value at which reconditioning is impossible without replacement of parts. If the
value is expected to exceed the service limit before next inspection and correction are performed, 13
replace the parts immediately. The operation over the specified values causes increase of
damage and requires the down time of machine, and also causes safety problems.
(3) Cautions to be Exercised at Judgment

1. Evaluation of measured data;
Disagreement of measuring conditions, variations of data peculiar to a new machine, and
measuring errors are to be evaluated. Determine generally at what levels measured values are
located, instead of determining whether or not values fall within or run out of the reference values.
2. Determining correction, adjustment or replacement;
Machine performances deteriorate with time as parts wear and some deteriorated performances
may be restored to new levels. Therefore, determine correction, adjustment or replacement,
depending upon the operating hours, kind of work and circumstances in which the machine is
placed, and condition the machine performances to its most desirable levels.
13-3
(4) Other Cautions to be Exercised

1. Parts liable to degrade;
Rubber products, such as, hydraulic hoses,
O rings, and oil seals deteriorate with time ; replace them at regular intervals or at overhauls.
2. Parts requiring regular replacement;
Out of critical hoses that are necessary to secure safety, we designate Very Important Parts
(V.I.P) and recommend that they should be replaced regularly.
3. Inspection and replacement of oils and greases;
In performing maintenance, it is necessary for the user to familiarize himself with how to handle
the machine safely, cautions to be exercised and inspection/lubrication procedures. Refer to the
operators manuals as well.
13-4
13.2 PERFORMANCE INSPECTION STANDARD TABLE
Unless otherwise specified, measure it on "H" mode.
13.2.1 STANDARD VALUE TABLE
13
13-5
13-6
13.3 MEASUREMENT OF ENGINE SPEED
13.3.1 MEASUREMENT OF ENGINE SPEED

(1) Warming up of engine
Start engine to raise the coolant temperature of engine to 60 to 90C degrees (140 to 194F degrees)
at surface of radiator upper tank.
The E/G coolant temperature gauge is used to measure. The range in white color shows the
temperature of approx. 65 to 105 C degrees (149 to 221F degrees), so confirm that the pointer
indicates the temperature within the white range.
(2) Engine speed measured value through service diagnosis (See below Fig.)
1. Turn "ON" the starter switch with the buzzer stop switch pressed.
2. A program No. and an actual engine revolution are displayed as the No.2 Item.
3. The screen advances like No.2, No.3....each time the "Wiper switch" on the gauge cluster is
pushed.
4. The screen returns like No.45, No.44....each time the "Washer switch" is pushed. 13
5. The display does not disappear unless the starter switch is turned to"OFF".
Service diagnosis for E/G speed measuring

(Example)
Switch for E/G speed indication
13-7
13.4 MEASUREMENT OF HYDRAULIC PRESSURE
13.4.1 PREPARING TO MEASURE HYDRAULIC PRESSURE

(1) Hydraulic equipment
6.9 MPa (1000psi) pressure gauge: 1unit
49 MPa (7100psi) pressure gauge: 1 units
(2 pcs in dozer specification)
Pressure measuring equipment and
instrument for analysis: 1 set
(2) Measuring cleanliness of hydraulic oil
Gauge port on main pump
After releasing air in the hydraulic oil tank, open the cover and sample oil in the hydraulic tank, and
measure with the instrument for analysis. If the measured value is higher than the standard value,
replace the return filter or change the hydraulic oil.
13.4.2 PLACE TO INSTALL PRESSURE GAUGE

(1) Main circuit
After releasing the pressure in hydraulic oil
tank and system, replace plugs PF1/4 of
main pump gauge ports (a1) with plugs for
pressure measurement, and attach
pressure gauge 49 MPa (7100 psi).
(2) Pilot circuit
Replace pilot gauge plug (a3) with plug
PF1/4 for pressure measurement, and
attach pressure gauge 6.9 MPa (1000 psi).
Plug for pilot pressure measurement
13-8
13.4.3 PRESSURE ADJUSTMENT POSITION

(1) Main control valve
13
Outside view
13-9
(2) Pilot relief valve

Pilot relief valve PR1 is built in Solenoid valve block.
Pilot relief valve position
(3) Swing port relief

The swing motor is equipped with plugs for pressure measurement, but the measurement is carried out
using gauge ports a1. (See "Gauge port on main pump" Fig.)
Swing port relief position
13-10
13.4.4 PROCEDURE FOR ADJUSTING RELIEF VALVE

(1) Pilot relief valve
Loosen nut and adjust it with adjust screw.
Tools: Spanner: 14.3 mm
Tools: Allen wrench: 4.2 mm
Pilot relief valve
(2) Main relief valve

(Travel section, ATT common section)
Loosen lock nut (2) and adjust it with adjust screw (1).
Tools: Spanner: 13 mm
Tools: Allen wrench: 4 mm
13
Main relief valve (Travel section, ATT

common section)
(3) Port relief valve (Boom, bucket, arm sections)

Loosen lock nut and adjust it with adjust screw.
Port relief valve (Boom, bucket, arm, sections)
13-11
(4) Swing port relief valve

When the adjusted pressure is 10 kgf/cm2 (142 psi) or less, loosen nut (71) and adjust it with cap
(90).
Swing port relief valve
13-12
13.5 MEASURING TRAVEL PERFORMANCES
13.5.1 TRAVEL SPEED

(1) Purposes
Measure the travel sprocket revolution and
confirm the performances between the
hydraulic pump and the travel motor of the
travel drive system.
(2) Conditions
Hydraulic oil temperature;
45 to 55C degrees (113 to 131F degrees)
Crawler on the right and left sides are One side lifted position
tensioned evenly.
(3) Preparation
Attach the reflection panel with a magnet to the
travel motor cover.
Swing the swing frame through 90C degrees as
shown in upper right Fig. and make the
crawler on one side take off the ground, using
the attachment.
Adhering position of reflection panel 13

(4) Measurement
Engine revolution; Hi idle
2-speed travel switch; 1st speed and 2nd speed
Measuring points; Right and left
Method, example 1;
Measure revolution with a stroboscope
Method, example 2;
Measure the revolutions per minute visually.
13.5.2 DEVIATION OF TRAVEL

(1) Purpose
Measure the amount of deviation at 20 (66 t)
travel and confirm the horizontal balance
between the hydraulic pump and the travel
motor of the travel drive system.
(2) Condition
RH and LH crawler are tensioned evenly. Travel position
Firm, level ground
13-13
(3) Preparation
1.
Straight course more than 30 m (108 ft)
2.
Travel position in which the Pin of Arm top is
lifted by about height of Boom foot.
Measuring method
(4) Measurement
1.
Measure the max. deviation distance of the
circular arc in the 20 m (66 ft) length, excluding
the preliminary run of 3 to 5 m (10 to 16 ft).
2.
Operate the travel lever at the same time.
13.5.3 PERFORMANCES OF PARKING BRAKE

(1) Purpose
Confirm that the parking brake holds a
stopped condition of the machine in a no-load
travel position and on a 15 degree slope.
(2) Condition
A slope with (Approx. 15 deg) gradient and a
stopped condition in a no-load travel position
Parking brake operating position
(3) Preparation
Place an angle meter on the shoe plate and
confirm that it makes an angle more than 15
degree.
Hang a perpendicular in parallel with the guide
frame rib on the track frame and put a mark
(matching mark) on the shoe plate.
(4) Measurement
Five minutes after the engine stops, measure
the movement distance of the matching mark.
Method of measurement
13-14
13.5.4 DRAIN RATE OF TRAVEL MOTOR

(1) Purpose
To measure the drain rate of the travel motor
and to confirm the performances of the travel
motor.
(2) Conditions
Engine revolution; Hi idle Location of stopper applied to travel sprocket
(3) Preparation
1.
Place a stopper under the RH and LH travel
sprockets.
2.
Stop the engine and release pressure from the
hydraulic circuit.
3.
Connect a hose with the drain port of the travel
motor and take drain in a container.
Method of measuring the drain rate of travel

motor
13
(4) Measurement ; at Travel Lock
1.
Start the engine and relieve pressure at the
full stroke of the travel lever.
2.
Measure the drain rate for 30 seconds of
relieving.
Unless you observe the rotary force direction at travel lock, rib "A" may be broken by stopper "B" in
some cases. (See Upper right Fig.)
13-15
13.6 MEASURING SWING PERFORMANCES
13.6.1 MEASURING SWING PERFORMANCES

(1) Purpose
Measure the swing time and confirm the
performances between the hydraulic pump
and the swing motor of the swing drive
system.
(2) Conditions
Firm, level ground
(3) Preparation
Put the bucket empty and extend the
boom, arm and bucket cylinder fully. Swing speed measuring position (at the min.
And the machine becomes a position of reach)
minimum reach.
(4) Measurement
Swing the machine by bringing the swing
lever to its full stroke. Measure the time
required to make two turns after one turn
of preliminary run and calculate the time
required for one turn.
13.6.2 PERFORMANCE OF SWING BRAKE

(1) Purpose
Confirm the braking torque performances by the swing relief valve.
(2) Conditions
Firm, level ground
(3) Preparation
1.
Put the bucket empty, retract the arm cylinder
fully and extend the bucket cylinders fully. And
move the boom so that the arm top pin is
positioned at same height with boom foot pin.
2.
Swing brake performance measuring position
Put a matching mark on the outer
circumference of the swing bearing of the upper
frame side and of the track frame side. Place
two poles (flags) on the front and back of the
extended line of the matching mark.
13-16
(4) Measurement
1.
When operating in regular swing speed, by
shifting lever to neutral position at pole position
the swing operation stops.
2.
Calculate the swing drift angle by the following
equation, after the upper swing body stops,
using the amount of deflection (m) of the
matching marks on the swing race and the
length (m) of the circumference of the swing
race:
13.6.3 PERFORMANCE OF SWING PARKING BRAKE

(1) Purpose
To confirm the mechanical performances of the
swing parking brake that is fitted to the inside
of the swing motor.
(2) Conditions 13
On a slope of 15 degree incline.
Stop the machine at right angles with the slope.
Put the bucket empty, retract the arm cylinder Swing parking brake performance measuring
fully and extend the bucket cylinder fully. And position
move the boom so that the arm top pin is
(3) Preparation
Put the angle meter on the shoe plate and
make sure that the angle is more than 15
degree.
Put a matching mark on the outer race side
and on the inner race side.
Measuring position of swing parking brake

performances
(4) Measurement
When five minutes has passed after the
engine stops, measure the length of the
movement of the matching marks.
13-17
13.6.4 DRAIN RATE OF SWING MOTOR

(1) Purpose
Measure the drain rate of the swing motor and
confirm the performances of the swing motor.
(2) Conditions
Hydraulic oil temperature; 45 to 55C degrees
(113 to 131F degrees)
(3) Preparation
1.
Stop the engine.
2.
Release pressure from inside the hydraulic
circuit.
3.
Disconnect the swing motor drain hose from
its end returning to the hydraulic oil tank and
take oil in a container.
4.
Put a plug to the tank side.
(4) Measurement; at Swing Lock

1.
Start the engine and put the side faces of
bucket against the inside of the right or left
shoe plates.
2.
Relieve the swing motor at full stroke of the
swing motion.
3.
Collect the amount of drained oil in a
container for 30 seconds.
13-18
13.7 MEASURING ATTACHMENT OPERATING PERFORMANCES
13.7.1 OPERATING TIME OF CYLINDERS

(1) Purpose
Measure the operating time of the boom,
arm and bucket and confirm the
performances between the hydraulic pump
and the cylinder of the attachment drive
system. Measuring position for bucket digging and
(2) Condition dump
Hydraulic oil temperature; 45 to 55C
degrees (113 to 131F degrees)
Operating time excluding the cushion stroke
(3) Preparation
Firm level ground with the bucket empty
(4) Measurement 1; Boom up and down Measuring position for boom up and down
With the boom operating lever at full stroke, motions
measure the required operating time of the
bucket between the ground surface and its
highest position.
Measurement 2; Arm in and out, bucket
digging and dump
In a position in which the tooth of the
Measuring position for arm in and out 13
bucket rises to a level of about 30 cm (1
motions
ft) above ground, measure the full stroke
operating time required with the arm and
bucket operating levers at full stroke.
Measurement 3
Use the attachment to press on the
ground and lower the boom until the lower
frame of dozer side is raised off the
ground. Under this condition, move the
dozer blade up and down with full stroke.
And measure each one-way cycle time of
dozer.
When lowering the boom, allow the bucket onto a soft ground or cushioning such as rubber tires ;
never put the bucket against concrete or other solid material.
13-19
13.7.2 OIL TIGHTNESS OF CYLINDERS

(1) Purpose
Confirm that the cylinder oil tight by checking the moving length of the cylinder rods.
(2) Condition
Hydraulic oil temperature; 45 to 55C degrees (113 to 131F degrees)
Firm, level ground
After cylinders are replaced, bleed off air from the cylinders, before checking for oil tightness.
Retract the arm cylinder rod 30 mm (1.2 in) from stroke end so that the piston does not match a
same range of the cushioning mechanism.
(3) Preparation
Put the bucket empty. Extend the arm cylinder rod 30 mm (1.2 in) from the most retracted
position. And extend the bucket cylinders fully. Then hold the boom so that the arm top pin is
(4) Measurement
Measure the items five minutes after the engine is turned off.
13-20
13.8 MEASURING PERFORMANCES OF SWING BEARING
(1) Purpose
Measure the gap between the lower frame
and the bottom face of the swing bearing
and estimate the degree of wear of the
swing bearing.
(2) Condition
Firm, level ground
The swing bearing mounting bolts are not
loosened.
The swing bearing is lubricated well, not How to measure the axial play of swing
making abnormal sound during turning. bearing
(3) Preparation
1.
Install a dial indicator to the magnetic
base and fix it to the lower frame.
2.
Direct the upper swing body and the lower
frame toward the travel direction, bring the Measuring position 1
probe of the dial indicator in contact with
the bottom surface of the outer race on the
swing body side and set the reading at
zero.
(4) Measurement 1 13
(Measuring position 1 and 2)
1.
Measuring position 2
Measure the displacement of the outer race
in the axial direction in position 1 [The
arm at 90 degrees to 110 degrees and
the crawler front is lifted by attachment
about 30cm (1ft)] and in position 2, using a
dial indicator.
(5) Measurement 2 (Measuring position 3)

1.
Retract the arm cylinder fully and extend
the bucket cylinder fully. And move the
boom so that the arm top pin is
positioned at same height with boom foot
pin. Then swing the bucket right and left by
Measuring position 3
man power. But in this case, the gap of
the attachment is included.
13-21
13.9 MECHATRO CONTROLLER
13.9.1 ENGINE CONTROL INPUT / OUTPUT
INPUT / OUTPUT
13.9.2 ENGINE CONTROL
ENGINE CONTROL EQUIPMENT
13-22
13.9.3 ENGINE CONTROL EQUIPMENT

(1) Governor motor and Mechatro controller
1. By operating accel dial, the input voltage
change is sensed by CN102-8 pin of
Mechatro controller.
2. The Mechatro controller computes the
input voltage, and outputs command to
governor motor, and incline governor lever
of engine to the swing angle
corresponding to accel dial set value.
3. The limit switch in the governor motor is
the starting point of the governor motor.
How to measure the axial play of swing

bearing
(2) Speed sensor

1. Installing place
Engine flywheel housing
2. Sensor attaching procedure
a.
Screw the sensor in until it contacts the
ring gear. In this case, do not damage the
top of the sensor. How to measure the axial play of swing 13
b. bearing
Rotate the sensor one turn (360 degrees)
reversely, and tighten with a lock nut
(Opposing flats 22 mm).
Tightening torque : 29.4±4.9N-m.
c.
Check the outqut voltage at the maximum
and minimum speed in no-load running.
d.
If the above-mentioned outqut is beyond the
range of table of table, loosen the nut
again And adjust the between the sensor
and ring gear to obtain the appropriate
voltage.
THE VOLTAGE FROM SENSOR

OUTPUT VOLTAGE
AC CURRENT
ENGINE SPEED VOLTAGE WAVEFORM
(EFFECTIVE VALUE)
MAXIMUM SPEED AT NO-LOAD 20V to 72V
7.1V to 25.5V
2420 min-1 *1 (PEAK - PEAK)
MINIMUM SPEED AT NO-LOAD 9V to 40V
3.2V to 14.2V
1050 min-1 (PEAK - PEAK)
13-23
*1: Only when traveling, the engine rotation becomes this speed.
When not traveling, the engine speed is 2,200 min-1.
13.9.4 ADJUSTMENT OF MECHATRO CONTROLLER OUTPUT (A ADJUSTMENT)

13.9.4.1 PURPOSE OF THE ADJUSTMENT
There is adjustment of mechatro controller as shown below; adjustment is an essential function to
ensure performance of machine.
(1) Adjustment of engine ("A" adjustment)

This adjustment is performed to set the relation between the acceleration command voltage output
from mechatro controller to engine controller and the engine speed.
13.9.4.2 IN CASES WHERE THE ADJUSTMENT OF MECHATRO CONTROLLER IS REQUIRED;

When the following parts are replaced or repaired, carry out the adjustment without fail.
(1) Mechatro controller

(2) Engine or engine controller
(3) Governor motor
13.9.4.3 PREPARATION
(1) Raise the oil temperature to about 50C deg. (122F deg.) to warm up the engine.
(2) Turn the air-con OFF.
(3) Turn the starter key switch OFF to stop the engine.
When the mechatro controller was replaced, the following error code is displayed because the
adjustment data is not entered.
A215, A225, A015
As the error codes other than those shown above may suggest failures of machine, repair the
machine into the ordinary operating condition according to Error Code List.
13-24
13.9.4.4 ADJUSTING PROCEDURE
Gauge cluster
(1) Adjustment of engine ("A" adjustment)
Procedure
1. Turn starter key switch ON keeping the
work mode selector switch on the gauge
cluster pressed, and hold it for 5 to 10
seconds, and then release it. (If the
engine is started, the following indication is 13
not displayed. Therefore do not start the
engine.)
2. Keep buzzer stop switch on gauge cluster

pressed for 5 seconds and release it and
the screen for selecting adjustment is
displayed. When adjustment data is not
entered in mechatro controller, "READY" is
indicated. If the adjustment operation is
once performed, "FIN" is indicated.
And the lever lock solenoid is
automatically released, disabling all
operations.
3. Press selector switch on gauge cluster to

display "adjust gap".
Move to the engine room, and adjust the
gap between the governor lever and the set
bolt (for engine of stop) to "0.2mm" so
that the length of rod assembly is "A"mm.
Distance A: 201 to 219 mm (SK70SR-2)
13-25
4. Press selector switch on gauge cluster to

display "START ENG".
"Engine SPEED" and "STEP" are indicated.
5. After starting engine, press selector switch

on gauge cluster, and "MEMORY ENG" is
displayed. And the controller returns from
"A" position of governor motor to Low idling
position, then the controller reads engine
rpm automatically from low idling to high
idling.
(When trying to limit the engine speed,
press the select switch on the gauge
cluster at the desired speed, and the
engine speed adjustment is completed.)
6. When normal HIGH idling speed is

detected, the adjustment is completed. And
"FINISH ENG" is displayed.
(Press the buzzer stop switch on gauge
cluster while this display is appeared, and
the adjustment of engine is completed.
And the engine speed returns to initially
preset speed wiyh throttle dial)
(2) Corrective actions taken when the adjustment can not be performed;
1. In cases where the adjustment of engine

can not be performed; And ERROR ENG"
is displayed.
Judging condition: The read engine speed
is 50rpm lower than the last value.
It is conceived that the error is caused by

the speed read error, pump load applied
to the engine in the course of adjustment.
a.
Checking speed sensor: Check that it is
free from wrong reading of speed due to
engine vibration.
13-26
［21. MECHATRO CONTROLLER］
21. MECHATRO CONTROLLER

TABLE OF CONTENTS
21.1 MECHATRO CONTROLLER …………………………………………………………………………………21-3

21.1.1 SUMMARY OF MULTI DISPLAY ………………………………………………………………………21-3
21.1.2 SELF DIAGNOSIS DISPLAY ……………………………………………………………………………21-7
21.1.3 SERVICE DIAGNOSIS DISPLAY FUNCTION ………………………………………………………21-8
21.1.4 TROUBLE HISTORY DIAGNOSIS………………………………………………………………………21-13
21.1.5 SET PROCEDURE OF MAINTENANCE SCHEDULE ………………………………………………21-14
21.1.6 ADJUSTING PROCEDURE OF DISPLAY ……………………………………………………………21-15
21.1.7 MECHATRO CONTROL EQUIPMENT …………………………………………………………………21-18
21
Book Code No. S5LF2114E01
21-1

S5LF2114E01
First Edition October, 2010 SK80MSR-2 : LF06-04547~
(AUS)
SK70SR-2 : YT06-18444~
(AUS)
21-2
21.1 MECHATRO CONTROLLER
21.1.1 SUMMARY OF MULTI DISPLAY

Electro-hydraulic conversion information is displayed on the multi display of the gauge cluster.
(1) Controls
21
(2) Gauge cluster
21-3
(3) Screen selection by work mode select switch

The mode after the engine starting is always the start from "S" mode.
The work mode is switched in order of "S" -> "H" each time the work mode select switch is pressed.
Select proper work mode shown below according to the work condition and the purpose.
For the selected work mode, refer to the table shown below.
・ S mode: For standard excavating work

・ H mode: For heavy duty excavating work
S mode
"S mode" is suitable for standard digging and
loading works and is in saving fuel consumption
and is in good balance to the workload.
H mode
"H mode" is suitable for heavy duty digging
work which gives priority to the workload at
the high speed.
21-4
(4) Maintenance screen displays

This screen displays the remaining time to the end of recommended replacement/change interval
specified for filter/oil.
For the initial set value of recommenced replacement/change time, see the following table.
Replacement interval
Item Default
Engine oil 500 Hr
Fuel filter 500 Hr
Hydraulic oil filter 1,000 Hr
Hydraulic oil 5,000 Hr
This menu is available for confirmation of the following items.

The maintenance screen changes each time the screen change switch is pressed.
1.
Remaining time display to the engine oil change
This display shows the remaining time to the
coming engine oil change.
2.
Remaining time display to the coming fuel filter
replacement
coming engine fuel filter replacement. 21
3.
Remaining time display to the coming hydraulic
oil filter replacement
coming hydraulic oil filter replacement.
4.
Remaining time display to the coming hydraulic
oil change
coming hydraulic oil change.
-The display automatically changes to the main screen, if switch is not operated for 30 seconds.
-For the setting procedure of maintenance time to be performed to the coming oil change in each
type and filter replacement, see the 21.1.5 SET PROCEDURE OF MAINTENANCE SCHEDULE.
21-5
(5) Gauge cluster display

After key is switched on and logo mark display disappears, screen for operator is displayed on multi
screen. The display functions of multi display are explained below.
1. Display function for operator:

Screen usually displayed during operation
1.1 Clock display function: Current time is displayed.
1.2 Self-diagnosis display:
When abnormality is detected on mechatro system like sensor, proportional valve, etc., this
displays error code.
1.3 Warning display:
When machine was thrown into dangerous state, or was failed, displays warning contents with the
symbol and statement. (For warning contents, see items shown below.)
1.4 Machine condition display: Displays machine operating condition.
2. Display function for maintenance:
Displays remaining time up to replacement/change of following items.
(1) Engine oil (2) Fuel filter (3) Hydraulic oil filter (4) Hydraulic oil
3. Failure history display function:
Stores abnormality occurred on mechatro system in the past and displays in order of recent
occurrence.
4. Mechatro adjustment display:
Displays procedure for adjustment of mechatro system like output adjustment, etc.
5. Service diagnosis display:
Displays information like pressure sensor sensed value, etc. output by mechatro controller
Error codes were stored as trouble history, and displayed on the monitor by the trouble history display
function.
21-6
21.1.2 SELF DIAGNOSIS DISPLAY

(1) Outline
This function identifies abnormality of control I/O signal like pressure, proportional valve, etc. during
machine operation through self diagnosis. The failed items are displayed on multi display of gauge
cluster. For connector No. and pin No., refer to the section "C-1 Mechatro controller" explained later.
Electric circuit diagram or harness is available to identify wire No. and wire color.
(2) I/O configuration
(3) Self diagnosis display items

As-displayed clock (Usually main screen). When error occurred, specifies failed section and the failure
type with the aid of error code.
21
21-7
21.1.3 SERVICE DIAGNOSIS DISPLAY FUNCTION

The current service diagnosis is displayed on multi display based on the data received from mechatro
controller. This section explains the operating procedure and examples of each screen. The values in
display changes according to the conditions like engine speed, attachment position, etc.
(1) Service diagnosis display screen operating procedure

1. Turn starter switch ON keeping buzzer stop switch pressed.
Buzzer stop switch
2. After logo mark is displayed, the screen changes in service diagnosis mode.
The service diagnosis screen "Mode No.1", "Screen No.1" is displayed first.
The service diagnosis is classified into three modes, 1, 2, and 3, and the present mode is
displayed in "Screen No.1".
The screen number each mode can display differs. The screen number displayed by each mode is
as follows.
・ Mode No.1 : Screen No.1 to No.30

・ Mode No.2 : Screen No.1, Screen No.31 to No.40
・ Mode No.3 : Screen No.1, Screen No.41 to No.50
3. The screen changes each time each switch is pressed from now on.
Washer switch
Screen gains by 1 in order.
(No.2-->No.3-->No.4-->...)
Wiper switch
Screen loses by 1 in order.
(No.24-->No.23-->No.22-->...)
Auto idling switch

Service diagnosis number advances from No.1
to No.3, and then returns to No.1.
(No.1-->No.2-->No.3-->No.1-->...)
Travel 1, 2 speed switch

Service diagnosis number advances from No.3
to No.1, and then returns to No.3.
(No.3-->No.2-->No.1-->No.3-->...)
4. Turn key switch OFF and the display of service diagnosis mode is closed.
21-8
(2) Service diagnosis display screen (Example)

The service diagnosis display screen list is shown below. The conditions for display are H mode,
engine low speed and lever to neutral position.)
1) Service diagnosis mode No.1
21
21-9
21-10
21
21-11
(3) Service diagnosis data list

Preface and precaution
The following is the data decided as normal status after service diagnosis for every operation. Use
these data to decide normal/abnormal status.
・ The values in following display are reference values with standard attachment attached machine.
・ The value of pressure sensor is calculated taking variation into accounts. When compared to
performance check reference criteria, measure it with the aid of calibrated measuring instrument.
・ The current of proportional valve is not the measured value, but command value. The measured
value should be confirmed by the value in the displayed value for each proportional valve.
・ The value in display during operation shows the value in steady state, rather than, at start of
operation.
・ Check on machine after sufficiently warming up machine.
・ The value in display may differ according to software version. Contact our dealer/distributor.
21-12
21.1.4 TROUBLE HISTORY DIAGNOSIS

The items of error detected by mechatro controller self diagnosis function are stored in mechatro
controller as one of history. And the errors are able to be indicated on the multi display.
The warning content is stored partially in "Travel history screen".
The error code for self diagnosis is stored.
(1) How to display

1. Turn starter switch on.
2. Press buzzer stop switch for 10 seconds continuously 5 times and the trouble history screen is
displayed.
3. Transmit trouble history data (One or many) and hour meter to gauge cluster.
-Hour meter and 4 failure data are displayed on screen. 21
-In case of more than 4 failure data, 4 data is displayed at a time for 10 seconds by turns.
4. Paging (Up and down)
-Press washer switch (UP), and the item moves upward.
-Press wiper switch (DOWN), and the item moves downward.
5. Turn starter switch off, and the display is disappeared.
(2) How to delete contents of trouble history

1. Display trouble history screen.
2. Press work mode change switch and buzzer stop switch simultaneously for 10 seconds or more.
3. When "NO ERROR" is displayed, the deletion is completed.
4. Turn starter switch off.
All the stored items are erased. It is impossible to erase data partially.
21-13
21.1.5 SET PROCEDURE OF MAINTENANCE SCHEDULE

This machine is equipped with multi-display
which allows confirmation of remaining time to
the coming replacement/change time of engine
oil, fuel filter, hydraulic oil filter and hydraulic
oil, therefore when the remaining time reaches
to Zero (0), replace or change engine oil, fuel
filter, hydraulic filter, hydraulic oil, etc. and
perform the initial setting by the following order.
Interval of replacement of parts is mentioned below.

-Engine oil: 500 Hr
-Fuel filter: 500 Hr
-Hydraulic filter: 1,000 Hr
-Hydraulic oil: 5,000 Hr
1. After displaying the display for setting by pressing the display change switch, set the respective
maintenance time for fuel filter, hydraulic oil filter and hydraulic oil while repeating the procedure 2 to 5.
2. The engine oil change time is displayed on the multi-display by 500 hours as a warning, but the
buzzer does not sound.
21-14
21.1.6 ADJUSTING PROCEDURE OF DISPLAY

(1) For operator
1) Clock Adjustment Switches
21
1. Turn starter key switch on and display main screen (a) for operator, and then press select switch
(8) and display "SWITCH STATUS CLOCK/CONTRAST" select screen (b).
2. In operations of FEED UP (4) and FEED DOWN (5), move cursor to "CLOCK/CONTRAST"
screen (c) and then press select switch (8) and the "ADJUST CLOCK ADJ CONTRAST" screen
(d) is displayed.
3. In operations of FEED UP (4) and FEED DOWN (5), move cursor to "ADJUST CLOCK" and then
press select switch (8) and the "ADJUST CLOCK" screen (e) is displayed.
4. Select any of "Y-M-D-H-M" in operation of FEED UP (4) and FEED DOWN (5) and vary the
values in operations of FEED UP (4) and FEED DOWN (5).
5. After adjustment, press select switch (8) and the adjusted values are stored as memory and time
setting is completed, and then the screen returns to main screen (a).
21-15
2) Contrast Adjustment Switches
1. Turn starter key switch on and display main screen (a), and press select switch (8) and display
"SWITCH STATUS CLOCK CONTRAST" select screen (b).
2. In operations of FEED UP (4) and FEED DOWN (5), move cursor to "SWITCH STATUS CLOCK
CONTRAST" screen (c) and then press select switch (8) and the "ADJUST CLOCK ADJ
CONTRAST" screen (d) is displayed.
3. In operations of FEED UP (4) and FEED DOWN (5), move cursor to "ADJUST CLOCK ADJ
CONTRAST" and then press select switch (8) and the "ADJUST CLOCK ADJ CONTRAST"
screen (e) is displayed.
4. Press select switch (8) and the "ADJ CONTRAST 55555" screen (f) is displayed.
5. Vary the values by pressing the desired figure in operations of FEED UP (4) and FEED DOWN
(5).
The available setting range is in 9 steps from "11111" to "99999".
[Example] 11111 (faint) --> 99999 (clear) * The initial set value is 55555.
6. Press select switch (8) and the adjusted values are stored as a memory and the contrast
adjustment is completed, and then the screen returns to main screen (a).
21-16
(2) Function for service

Following items are provided for adjustment of service function.
Item CONTENTS
Language Language selection
Rise-up wiper Wiper control change (When cab is changed)
Idle stop ON/OFF of auto idle stop (ON/OFF of adjustment for user) and time adjust
Swing alarm ON/OFF of swing alarm (ON/OFF of adjustment for user)
Engine speed ON/OFF of engine rpm display
Change of starter mode Change of start mode
21
21-17
21.1.7 MECHATRO CONTROL EQUIPMENT

(1) C-1 Mechatro controller
1) Outside view
2) List of connectors
21-18
21
21-19
21-20
21
21-21
21-22
(2) Gauge cluster (symbol C-2)

1) General view
2) Connector CN-600 (Harness side)

No. Item name Wire color No. Item name Wire color
Gauge cluster --> Mechatro
GND source (+24V Battery direct
1 controller (RS232C White 5 Yellow / Black
connection)
communication)
Mechatro controller --> Gauge
2
cluster (RS232C communication)
Red 6 GND Black 21
3 Reserved - 7 Source (+24V starter switch ON) White
4 Reserved - 8 GND (RS232C communication) Black
3) Function
a. It processes signals by communication between the gauge cluster and the mechatro controller,
displays them in lamps, displays them in LCDs and actuates the buzzer.
b. It outputs coolant temperature signals, fuel level signals and panel switch signals to the mechatro
controller through the communication port.
4) Summary of display and drive item

No. Item Remarks
1 Monitar display LCD dot 120X168
2 Gauge display (Coolant temp., Fuel level) Stepping motor
3 -
4 Buzzer Piezo-electricity type
5 Screen change switch
6 Buzzer stop switch
7 Work mode select switch
8 Back light LED
21-23
(3) Relay & fuse box (symbol E-1)

1) General view
21-24
2) Circuit diagram
21
21-25
21-26
21
21-27
(4) High pressure sensor : YN52S00048P1
(5) Low pressure sensor : LC52S00019P1
21-28
［22. HYDRAULIC SYSTEM］
22. HYDRAULIC SYSTEM

TABLE OF CONTENTS
22.1 SUMMARY ………………………………………………………………………………………………………22-3

22.1.1 FUNCTION AND FEATURES OF HYDRAULIC CIRCUIT …………………………………………22-3
22.2 HYDRAULIC CIRCUITS AND COMPONENTS ……………………………………………………………22-4
22.2.1 STANDARD SPECIFICATION……………………………………………………………………………22-5
22.2.2 OFFSET SPECIFICATION (OPT.) ………………………………………………………………………22-6
22.2.3 BREAKER SPECIFICATION (For OFFSET OPT.) …………………………………………………22-7
22.2.4 HAND CONTROL BREAKER SPECIFICATION (For OFFSET OPT.) ……………………………22-8
22.3 HYDRAULIC CIRCUIT OPERATION ………………………………………………………………………22-10
22.3.1 COLOR CODING STANDARD FOR HYDRAULIC …………………………………………………22-10
22.3.2 NEUTRAL CIRCUIT ………………………………………………………………………………………22-10
22.3.3 TRAVEL CIRCUIT …………………………………………………………………………………………22-12
22.3.4 BUCKET CIRCUIT …………………………………………………………………………………………22-14
22.3.5 BOOM CIRCUIT ……………………………………………………………………………………………22-16
22.3.6 SWING CIRCUIT …………………………………………………………………………………………22-20
22.3.7 ARM CIRCUIT ……………………………………………………………………………………………22-22
22.3.8 DOZER CIRCUIT …………………………………………………………………………………………22-26
22.3.9 COMBINED CIRCUIT ……………………………………………………………………………………22-28 22
22-1

S5YT2215E01
(AUS)
22-2
22.1 SUMMARY
22.1.1 FUNCTION AND FEATURES OF HYDRAULIC CIRCUIT

The hydraulic circuits are built up with the following functions and features in order to achieve easy
operability, safety, mass volume handling and low fuel consumption.
22
22-3
22.2 HYDRAULIC CIRCUITS AND COMPONENTS
STANDARD SPECIFICATION SK70SR-2

No. NAME PART No. MODEL No.
1 PUMP ASSY (WITH GEAR PUMP) YT10V00023F1 PVC80RC13
2 CONTROL VALVE YT30V00047F4 iK18-8505
3 SWING MOTOR UNIT YT15V00015F1 SG025E-142
4 TRAVEL MOTOR YT15V00012F1 SGM-04D-S-09KL
5 BOOM CYLINDER YT01V00034F1 110-70-916
6 ARM CYLINDER YT01V00031F1 95-65-833
7 BUCKET CYLINDER YT01V00032F1 80-55-735
8 DOZER CYLINDER YT01V00035F1 K87000001
9 SWIVEL JOINT YT55V00009F1
10 PILOT VALVE (ATT) YN30V00111F1 PV48K2004
11 PILOT VALVE (TRAVEL) YN30V00070F2 PVD6PC4017A
12 PILOT VALVE (DOZER) YY30V00061F2 16528-0000A
13 SOLENOID VALVE YT35V00027F1 3KWE5A-30/G24WS-356
14 SUCTION STRAINER YT50V00003F1
15 RETURN FILTER YR52V01004F1
16 CHECK VALVE 2436R576F1 Y-2389
17 CHECK VALVE 2436R576F5 Y-2389
18 AIR BREATHER YN57V00004F1 AB0210GA008A
19 INLINE FILTER YN50V00020F1 Y-457400
20 CHECK VALVE (SLOW RETURN) PF21V00006P1
21 CHECK VALVE (SLOW RETURN) YY21V00001F1
23 Multi control valve lever less YN30V00113F1
The part numbers may be changed due to modification, so use only the numbers for references.
22-4
22.2.1 STANDARD SPECIFICATION
22
22-5
22.2.2 OFFSET SPECIFICATION (OPT.)
22-6
22.2.3 BREAKER SPECIFICATION (For

OFFSET OPT.)
22
22-7
22.2.4 HAND CONTROL BREAKER

SPECIFICATION (For OFFSET OPT.)
22-8
22
22-9
22.3 HYDRAULIC CIRCUIT flows into P port of C/V (2). This oil branches
off to the flow control valve (A-1) and to P-T
OPERATION
passage of each spool, and return to the tank.
22.3.1 COLOR CODING STANDARD FOR This return oil flows via negative control orifice
HYDRAULIC (A-2), and the negative control pressure is
Blue generated, and the oil flows from Pn port to Pi1
port of the pump. Consequently, the negative
Feed, drain circuit
control pressure pushes the piston U (A-3). On
0.34~ 0.59 MPa (50~85 psi)
the other hand, tank pressure is led from Pr port
Green
of C/V (2) to Pb port of the pump, this pressure
Return, make-up circuit, pushes piston (back pressure compensation) to
0.44~0.59 MPa (64~86 psi) the reverse direction of piston U (A-3).
Purple The difference of thrust between two pistons
Secondary pilot pressure, pushes the piston rod (A-5). And the self pressure
0.59~3.5 MPa(85~508 psi) leads the power piston (A-6) to the power piston
chamber (A-7). This motion of piston adjusts the
Red
tilting angle of swash plate in accordance with
Primary pilot pressure,
negative control pressure.
3.5~5.0 MPa (508~ 725 psi)
Orange 22.3.2.3 FLOW CONTROL VALVE
Main pump drive pressure, (1) When the actuator is operated, the pressurized
3.5~29.4 MPa (508~4270 psi) delivery oil from the pump flows via the opening
Blue tone of the meter-in of spool, and is fed to the
actuator.
At valve operation
(2) Simultaneously, the working pressure of actuator,
Red valve
namely the load sensing pressure (hereinafter
When proportional valve (reducing) is operating
called LS pressure), is generated.
Red solenoid This LS pressure acts on the spring chamber of
In active and exciting the flow control valve (A-1).
Displaying the flow circuit and standby circuit when (3) Simultaneously, the pump delivery pressure is led
operating. to the opposite side of the spring chamber of
Regarding the electrical symbols in this manual, refer to the flow control valve.
the electric circuit diagram. (4) The pump pressure is regulated to become the
"Load sensing pressure + spring force" with the
22.3.2 NEUTRAL CIRCUIT flow control valve. In this way the differential
22.3.2.1 SAFETY LOCK LEVER AND PILOT CIRCUIT pressure between the pump pressure and the LS
(1) Purpose pressure is kept constant. And the before and
To protect attachment from unexpected operation after differential pressure of meter-in and
for safety. meter-out are kept constant.
(2) Principle Consequently, the flow rate in accordance with
Cut pressure source of pilot valve for operation. the opening area is fed to the actuator.
(3) Operation
After engine starts, push down the safety lock
lever, the solenoid valve (SV-4) of the proportional
valve block (13) is functioned, and the pilot
operation circuit is actuated.
22.3.2.2 PUMP CONTROL

(1) Operation
1. Pump delivery oil is delivered from D1 port and
22-10
22
Neutral circuit: Safety lock lever ON
22-11
22.3.3 TRAVEL CIRCUIT (Refer to "Chapter 24. Components System: Travel

22.3.3.1 TRAVEL MOTOR FUNCTIONS Motor Function")
(1) Functions
1. Prevention from overrun on a slope 22.3.3.5 TRAVEL MAIN CIRCUIT (RIGHT AND LEFT
2. Shockless relief valve prevents sudden stop by SIMULTANEOUS OPERATION)
inertia (1) Purpose
3. High/Low 2 speed switching mechanism Control of travel deviation caused by different pressure
4. Travel parking brake loading
5. Travel speed automatic switching mechanism
(2) Operation
22.3.3.2 TRAVEL FORWARD PILOT SIMULTANEOUS As for the oil flow at simultaneous operation, the
OPERATION CIRCUIT following explanation is based on the assumption,
(1) Operation that the loaded pressure of right travel is higher than
1. Start travel right and left at the same time with left. Before the oil flows through the right and left
control lever, and the pilot proportional secondary travel spools, and the oil flows into the travel motor
pressure is delivered through P/V (11) 2, 4 ports, (4) via A2, A3 ports, the oil from P port flows via
at the same time select higher pressure and the the pressure compensation valve (A). In this case, the
higher pressure is delivered through 5, 6 ports, right higher loading pressure acts on the pressure
then acts on low pressure sensors (SE10) (SE9). compensation valve (A), and the pressure narrows
2. Pilot proportional secondary pressure flows into the opening of compensation valve. Consequently,
a2, a3 ports of control valve (2), acts on travel the travel deviation is controlled, because the left
spool, and switches main circuit. loading pressure increased, and the inflow rate is
3. The signal output by low pressure sensor is adjusted.
input to mechatro controller, and the output
voltage of low pressure sensor is input to
mechatro controller, and the engine speed is
changed from 2200 rpm to 2400 rpm.
22.3.3.3 TRAVEL 2 SPEED SOLENOID COMMAND

CIRCUIT
(1) Purpose
Change travel motor speed with switch.
(2) Operation
Press switches with rabbit and turtle marks on travel
lever grips, and the solenoid (SV-3) of proportional
valve block (13) is excited and is switched, and
solenoid command is output by port A2 and sends to
P port of travel motor (4), opens oil passage to high
speed piston, the self-pressure is led to the swash
plate and the swash plate is changed to high speed
tilting angle (small tilting).
22.3.3.4 TRAVEL MAIN CIRCUIT (RIGHT OPERATION)

(1) Operation
With travel pilot operation, the travel speed is
switched, and the oil delivered through D1 port of
main pump passes through C/V P-A2, flows into P2
port of travel motor (4) through C port of swivel joint
(9) allowing travel motor to perform the operation.
22-12
22
Travel circuit: Travel 2nd. speed operation
22-13
22.3.4 BUCKET CIRCUIT side through C/V (2) B6 port. And the return oil from
22.3.4.1 BUCKET DIGGING PILOT CIRCUIT cylinder rod side flows into tank circuit from A6 port
(1) Operation while being restricted by bucket spool.
Start bucket digging operation, and pilot proportional
secondary pressure is output through port (1) of right
pilot V (10), and flows into C/V (2) b6 port, and
switches bucket spool.
22.3.4.2 AUTO ACCEL OPERATION

(1) Principle
Start operating with signal output by low pressure
sensor.
(2) Operation
[Lever in neutral position]
If the pilot primary pressure does not be detected for
4 seconds or more, even if the accel dial position is
in maximum, the engine speed becomes 1200 rpm.
[Lever in operation position]
In case of the standard specification machine, when
0.6MPa acts on the low-pressure sensors of bucket,
boom, swing, arm, and dozer, the proportional
voltage from a low-pressure sensor enters
mechatro-controller.Consequently, in accordance with
the lever operation, engine speed is returned to the
speed which was set by acceleration dial.
22.3.4.3 ENGINE OVERLOAD PREVENTION BY PUMP

POWER SHIFT CONTROL
(1) Operation
1. As the pump delivery pressure rises, the
pressure (self-pressure) exerted on control piston
(C-1) of power shift is also raised, and when the
pressure rises to the pressure which resists to the
thrust of piston U (C-2) and piston (pressure
compensation) (C-3), the piston is pushed back.
2. After the piston is pushed back to the position
where piston U self-pressure balances the
negative control pressure, the self-pressure pushes
back piston rod (C-4) and is led to internal
pressure of piston chamber (C-6) of power piston
(C-5).
3. Then, the tilting angle becomes smaller and
reduces the delivery flow rate of the pump, and
it helps to prevent engine overload.
22.3.4.4 BUCKET DIGGING MAIN CIRCUIT

(1) Operation
With pilot operation, the pressurized oil switches the
bucket spool, and is fed into bucket cylinder head
22-14
22
Bucket circuit: Bucket digging operation
22-15
22.3.5 BOOM CIRCUIT

22.3.5.1 BOOM RAISE PILOT CIRCUIT
(1) Operation
1. Start boom raise operation, and pilot proportional
secondary pressure from right pilot valve (10) is
output through port (3), and acts on b5 port of
C/V (2).
2. Then, the secondary pressure fed into C/V (2)
b5 port switches boom spool.
22.3.5.2 BOOM MAIN CIRCUIT

(1) Purpose
Boom raise speed up
(2) Operation
1. Pump delivery oil flows into P port of C/V (2) and
is led to boom spool.
2. After passing through spool, the delivery oil
pushes and open lock valve (D-1), passes through
B5 port and holding valve (19), and then is fed to
the head side of boom cylinder (5).
3. Simultaneously, the negative pressure of boom is
transformed into load sensing pressure and acts
on flow control valve (D-2). While keeping the
differential pressure of pump delivery pressure and
LS pressure constant, the pump flow rate in
accordance with the negative control pressure is
decided.
Hereinafter, LS is short for Load sensing.
4. Return oil from the rod side through A5 port of

C/V passes through boom spool and boom
pressure compensation valve (D-4), and branches
in oil that passes through boom spool and boom
pressure compensation valve and returns to the
tank and in oil returned to the tank through
sub-bleed opening provided on spool without
passing through pressure compensation valve
(D-4).
22-16
22
Boom circuit: Boom raise (up) operation
22-17
This section describes the boom lower operation.
22.3.5.3 BOOM LOWER PILOT CIRCUIT

(1) Operation
1. After boom down operation, pilot proportional
secondary pressure is delivered from port 4 of
right pilot valve (10), is branched out in 2
circuits and acts on a5 and Pi1 port of C/V (2).
2. And the proportional secondary pressure led to a5
port of C/V (2) switches boom spool. The
proportional secondary pressure led to Pi1 port
of C/V (2) releases the lock of boom lock valve.
22.3.5.4BOOM LOWER MAIN CIRCUIT

(1) Operation
1. Pump delivery oil flows into P port of C/V (2) and
then flows into boom spool.
2. After passing through spool, the delivery oil is
fed to the rod side of boom cylinder (5) through
A5 port. Simultaneously, the loading pressure for
boom down operation acts on flow control valve
(E-1) as the load sensing pressure.
(See "Chapter 24. Components System: Control
Valve".)
The flow is regulated in the pump delivery flow
rate in accordance with the negative control
pressure by keeping the differential pressure of
pump delivery pressure and load sensing pressure
constant.
3. The return oil from the head side of boom
cylinder (5) flows into B5 port of C/V (2).
4. The oil led through B5 port of C/V (2) reaches
to boom lock valve, but because the lock valve is
released by pilot proportional secondary pressure
for boom down operation, the oil flows into boom
spool.
5. And the pressure oil is restricted by passing
through orifice passage provided on boom spool,
and returns to the tank through boom pressure
compensation valve (E-2).
22-18
22
Boom circuit: Boom lower (down) operation
22-19
22.3.6 SWING CIRCUIT constant.

22.3.6.1 SWING RIGHT PILOT CIRCUIT (See "Chapter 24. Components System: Control
(1) Operation Valve".)
1. Start swing right operation and pilot proportional And for swing spool, the bleed opening for return oil
secondary pressure through port (6) of left pilot from swing spool to the tank is not closed
valve (10) is output, and acts on low pressure completely even when swing lever is fully manipulated.
sensor (SE40), and at the same time the
pressure flows into a1 ports of C/V (2). 22.3.6.4 SWING MOTOR FUNCTION
2. Then, the secondary pressure fed into C/V (2) (1) Anti-cavitation circuit of swing reduction gear
a1 port switches swing spool. (2) Shockless relief for swing anti-reaction
22.3.6.2 SWING AUTO PARKING BRAKE

(1) Purpose
Swing lock and parking in neutral position
(2) Principle
Release only when required to operate mechanical
brake.
(3) Operation
1. Usually, the swing parking solenoid (SV39) is
excited by turning starter switch key "ON", and
the parking brake is actuated. In this time the
pilot primary pressure is not conducted.
2. Only when operation secondary pressure during
swing and arm digging operation acts on any of
low pressure sensor (SE40, 41, 7), it release the
excitation to swing parking SOL.
3. After 5 seconds when the pressure of low
pressure sensor (SE40, 41) from swing operation
has disappeared, the swing parking SOL (SV-1)
is excited. And in case of arm in operation, at the
same time when the pressure of pressure sensor
(SE7) for arm in operation has been
disappeared, the swing parking SOL (SV-1) is
excited.
22.3.6.3 SWING MAIN CIRCUIT

(1) Operation
Pump delivery oil flows into P port of C/V and is led
to swing spool. The oil passed through spool flows
through swing pressure compensation valve (F-1) and
flows into A port of swing motor through A1 port of
C/V (2), and consequently has the swing motor
rotated clockwise. And simultaneously, the loading
pressure for swing operation acts on flow control valve
(F-2) as load sensing pressure and the flow is
regulated in the pump delivery flow rate in accordance
with negative control pressure by keeping the
differential pressure to the pump delivery pressure
22-20
22
Swing circuit: Swing operation (right)
22-21
22.3.7 ARM CIRCUIT

22.3.7.1 ARM CONTROL PILOT CIRCUIT
(1) Operation
1. Start arm in operation, and pilot proportional
secondary pressure is output through port (7) of
left pilot valve (10), and acts on low pressure
sensor (SE7), and at the same time the pressure
branches into 2 circuits and acts on Pi2 and b7
ports of C/V (2).
2. Then, the secondary pressure acted on C/V (2)
b7 port switches arm spool. And secondary
pressure acted on Pi2 port of C/V (2) releases
the arm lock valve.
22.3.7.2 RECIRCULATION FOR ARM-IN OPERATION

AND MAIN CIRCUIT
(1) Purpose
Speed up of arm-in operation
(2) Principle
To have a part of return oil in arm-in operation
confluxes with feed oil
(3) Operation
1. Pump delivery oil flows into arm spool through P
port of C/V (2). After passing through arm spool,
flows through arm pressure compensation valve
(G-1) and is fed to the head side of arm
cylinder (6) through B7 port of C/V (2).
Simultaneously, the loading pressure for arm-in
operation acts on flow control valve (G-3)
provided in C/V (2) as the load sensing pressure.
Valve".)
The flow is regulated in the pump delivery flow
rate in accordance with the negative control
pressure by keeping the differential pressure of
pump delivery pressure and load sensing pressure
constant.
2. On the other hand, the return oil from the rod
side of arm cylinder (6) flows through A7 port of
C/V (2) and is led to arm spool through arm
lock valve released by pilot proportional secondary
pressure which acts on Pi2 port.
3. The return oil is branched into the 2 oil flows.
One returns to the tank while being restricted by
passing through orifice passage provided on arm
spool. Another is recirculated in arm cylinder
feed pressure by boost check valve (G-2) for
recirculation.
22-22
22
Arm circuit: Arm in (digging) operation
22-23
This section describes the following operations.
22.3.7.3 ARM OUT PILOT CIRCUIT

(1) Operation
1. Start arm out operation, and the pilot proportional
secondary pressure is output through port (8) of
left pilot valve (10), and acts on a7 port of C/V
(2), and switches arm spool.
22.3.7.4 ARM OUT MAIN CIRCUIT

(1) Operation
1. Pump the delivery oil flows into arm spool through
P port of C/V (2). And the delivery oil flows
through arm pressure compensation valve (H-1)
and is fed to the rod side of arm cylinder (6)
through A7 port of C/V (2).
2. Simultaneously, the loading pressure for arm
operation acts on flow control valve (H-2) provided
in C/V (2) as the load sensing pressure and the
flow is regulated in the pump delivery flow rate
in accordance with negative control pressure by
keeping the differential pressure to pump pressure
constant.
Valve".)
3. And, the return oil from head side of arm cylinder
(6) is led to arm spool, and returns to the oil
tank.
22-24
22
Arm circuit: Arm out (extend) operation
22-25
22.3.8 DOZER CIRCUIT

22.3.8.1 DOZER UP PILOT CIRCUIT
(1) Operation
1. After dozer up operation, the pilot proportional
secondary pressure flows out through B port of
dozer pilot valve (12), and acts on b4 port of C/V
and switches the dozer spool.
22.3.8.2 DOZER UP MAIN CIRCUIT

(1) Operation
1. Pump delivery oil flows into dozer spool through
P port of C/V (2). After passing through spool,
the oil is fed to the rod side of dozer cylinder
(8) through F port of swivel joint (9) from B4
port of C/V (2).
2. Simultaneously, the loading pressure for dozer
operation acts on flow control valve (I-2)
provided in C/V (2) as the load sensing pressure
and the flow is regulated in the pump delivery
flow rate in accordance with negative control
pressure by keeping the differential pressure to
pump pressure constant.
Valve".)
3. On the other hand, the return oil from the head
side of dozer cylinder (8) flows to A4 port of
C/V (2) through G port of swivel joint (9), and
passes through spool and dozer pressure
compensation valve (I-1) and returns to the oil
tank through R1 port.
22-26
22
Dozer circuit: Dozer raise (up) operation
22-27
22.3.9 COMBINED CIRCUIT

22.3.9.1 BOOM UP, TRAVEL, AND MAIN CIRCUIT
(1) Purpose
During the simultaneous operation of travel and other
attachment, the large speed variation and the
deviation do not occur.
(2) Principle
The pressure compensation valve of lighter load
actuator functions, and controls the flow by regulating
the loading pressure.
(3) Operation
Pump delivery oil flows into P port of C/V (2) and is
led to boom and right and left travel section. We
explain the case where the loading pressure for
boom up operation is high on that occasion.
First, the loading pressure for boom operation acts
on right and left travel compensation valves (L-1, L-2).
Consequently the oil which passes through travel
spool and flows into travel motor (4) through A2 and
A3 ports is restricted by travel pressure
compensation valves (L-1, L-2) and is raised to the
loading pressure for boom operation, and then the oil
quantity fed to travel motor (4) reaches uniformity
and the deviation is restrained.
But the travel spool is provided with notch which
leads the oil to A2 and A3 ports of C/V (2) without
passing through travel pressure compensation valves
(L-1, L-2). The travel and boom (ATT) speeds are
controlled by connecting to this passage.
22-28
22
Combined operation: Boom raise (up) / Travel simultaneous operation in Travel straight function
22-29
22-30
［23. ELECTRICAL SYSTEM］
23. ELECTRICAL SYSTEM

TABLE OF CONTENTS
23.1 ELECTRIC CIRCUIT DIAGRAM ………………………………………………………………………………23-3

23.2 ELECTRICAL EQUIPMENT & HARNESS …………………………………………………………………23-11
23.3 HARNESS ………………………………………………………………………………………………………23-12
23.3.1 HARNESS LIST ……………………………………………………………………………………………23-12
23.3.2 INSTRUMENT PANEL ASSY ……………………………………………………………………………23-13
23.3.3 CONTROLLER INSTALL …………………………………………………………………………………23-14
23.3.4 OPERATOR'S CONTROL (1/2) …………………………………………………………………………23-15
23.3.5 UPPER ELECTRIC ASSY ………………………………………………………………………………23-17
23.3.6 UPPER HARNESS ASSY (1/6) …………………………………………………………………………23-18
23.3.7 UPPER HARNESS ASSY (FLOOR) (1/2) ……………………………………………………………23-34
23.3.8 HARNESS ASSY (TWO - SPEED SELECT SWITCH) ……………………………………………23-42
23.3.9 CAB HARNESS ASSY (1/2) ……………………………………………………………………………23-44
23.3.10 BOOM HARNESS ASSY ………………………………………………………………………………23-50
23.3.11 BOOM LIGHT INSTALL …………………………………………………………………………………23-50
23.3.12 UPPER LIGHT INSTALL ………………………………………………………………………………23-51
23.3.13 ALARM ASSY ……………………………………………………………………………………………23-51
23
23-1

S5YT2315E01
(AUS)
23-2
23.1 ELECTRIC CIRCUIT DIAGRAM
23
23-3
23-4
23
23-5
23-6
23
23-7
23-8
23
23-9
23-10
23.2 ELECTRICAL EQUIPMENT &

HARNESS
23
23-11
23.3 HARNESS
23.3.1 HARNESS LIST
23-12
23.3.2 INSTRUMENT PANEL ASSY
23
23-13
23.3.3 CONTROLLER INSTALL
23-14
23.3.4 OPERATOR'S CONTROL (1/2)
23
23-15
23.3.4 OPERATOR'S CONTROL (2/2)

23.3.4.7 RADIO INSTALL : YT54E00007F1 (02)
23-16
23.3.5 UPPER ELECTRIC ASSY
23
23-17
23.3.6 UPPER HARNESS ASSY (1/6)
23-18
23
23-19
23-20
23
23-21
23-22
23
23-23
23.3.6.1 UPPER HARNESS (1/9) : YT13E01217P2
23-24
23
23-25
23-26
23
23-27
23-28
23
23-29
23-30
23
23-31
23-32
23.3.6.2 STARTER CABLE : YT13E01145P2
23
23-33
23.3.7 UPPER HARNESS ASSY (FLOOR)

(1/2)
23-34
23.3.7 UPPER HARNESS ASSY (FLOOR) (2/2)
23
23-35
23.3.7.1 FLOOR HARNESS (1/5) : LF13E01057P3
23-36
23
23-37
23-38
23
23-39
23-40
23.3.7.3 FLOOR GROUNDING CABLE : LE13E01005P1

23.3.7.4 CAB SUB HARNESS: YY13E01268P1
23
23-41
23.3.8 HARNESS ASSY (TWO - SPEED

SELECT SWITCH)
23-42
23.3.8.1 HARNESS : LF11E01001P1
23
23-43
23.3.9 CAB HARNESS ASSY (1/2)
23-44
23.3.9 CAB HARNESS ASSY (2/2)
23
23-45
23.3.9.1 CAB HARNESS (1/3) : LF14E01031P3
23-46
23.3.9.1 CAB HARNESS (2/3) : LF14E01031P3
23
23-47
23.3.9.1 CAB HARNESS (3/3) : LF14E01031P3
23-48
23.3.9.6 HOUR METER HARNESS : YN11E01205P1

23.3.9.7 SOCKET HARNESS : LF14E01033P1
23.3.9.9 HARNESS : LF53E01001P1
23
23-49
23.3.10 BOOM HARNESS ASSY

23.3.10.1 BOOM HARNESS : YT15E01004P2
23.3.11 BOOM LIGHT INSTALL
23-50
23.3.12 UPPER LIGHT INSTALL

23.3.13 ALARM ASSY
23
23-51
23-52
［24. COMPONENTS SYSTEM］
24. COMPONENTS SYSTEM

TABLE OF CONTENTS
24.1 HYDRAULIC COMPONENTS …………………………………………………………………………………24-3

24.1.1 HYDRAULIC PUMP & REGULATOR …………………………………………………………………24-3
24.1.2 CONTROL VALVE …………………………………………………………………………………………24-20
24.1.3 PILOT VALVE (ATT)………………………………………………………………………………………24-55
24.1.4 PILOT VALVE (TRAVEL)…………………………………………………………………………………24-59
24.1.5 SWING MOTOR UNIT ……………………………………………………………………………………24-64
24.1.6 TRAVEL MOTOR …………………………………………………………………………………………24-75
24.1.7 SWIVEL JOINT ……………………………………………………………………………………………24-90
24.1.8 CYLINDER …………………………………………………………………………………………………24-92
24.2 ELECTRICAL EQUIPMENT ……………………………………………………………………………………24-99
24.2.1 ELECTRICAL EQUIPMENT LIST ………………………………………………………………………24-99
24.2.2 SPECIFICATIONS ELECTRICAL EQUIPMENT ………………………………………………………24-102
24
24-1

S5YT2415E01
(AUS)
24-2
24.1 HYDRAULIC COMPONENTS
24.1.1 HYDRAULIC PUMP & REGULATOR

24.1.1.1 SUMMARY
(1) General view and hydraulic port
Hydraulic pump & regulator
(2) Specifications
24
24-3
24.1.1.2 CONSTRUCTION
Construction of hydraulic pump & regulator
24-4
No. NAME Q'TY No. NAME Q'TY No. NAME Q'TY

1 SHAFT 1 31 SPRING 1 61 ROD RE 1
2 OIL SEAL 1 32 SPRING GUIDE 1 62 SPRING 6
3 SHIM REC 33 CAP: PF1/16 6 63 PISTON RE 1
4 HOUSING 1 34 O-RING: A90 6 64 COVER 1
5 TAPERED ROLLER BRG. 1 35 ROD PW 1 65 SPRING 1
6 SCREW: M5X10 2 36 SLEEVE 1 66 BUSHING 2
7 CRADLE H 1 37 PIN 1 67 SPRING 2
8 CAM 1 38 SERVO CASE 1 68 PLUG 2
9 RETURN PLATE 1 39 ROD 1 69 O-RING: 1B P22.4 1
10 PISTON ASSY 9 40 PISTON B 1 70 CAP RE: PF3/4 1
11 CYLINDER 1 41 POWER PISTON LAS 1 71 COUPLING 1
12 PORT PLATE CW 1 42 PISTON 1 72 GEAR PUMP 1
13 RING 1 43 SPRING 1 73 SOCKET BOLT: M10X30 1
14 BUSHING 1 44 O-RING 1 74 SNAP RING 1
15 SPRING 1 45 SERVO COVER H 1 75 PLUG 1
16 CRADLE L 1 46 PISTON H 1 76 O-RING: P11 A90 3
17 RETAINER SPH 1 47 SERVO COVER 1 77 LINK 1
18 O-RING 1 48 PISTON U 1 78 PIN 1
19 PARALLEL PIN 6 49 SOCKET BOLT: M6X70 4 79 O-RING: G50 A90 1
20 NEEDLE BRG. 1 50 O-RING: 1B P10 1 80 SOCKET BOLT: M16X90 3
21 O-RING: 1B G55 1 51 BUCK UP RING 1 81 CAPSCREW: M8X25 2
22 NUT: M10 1 52 STOPPER 1 82 WASHER 2
23 NUT: M20 1 53 SET SCREW: M12X30 1 83 SOCKET BOLT: M16X110 1
24 O-RING: P9 A90 4 54 NUT: M12 1 84 CAP: PF1/4 2
25 CAP SP: PF1 1 55 CAP: PF1 1 85 CAP ASSY 1
26 O-RING: 1B P29 2 56 SPRING 1 86 SERVO CASE ASSY 1
27 SLEEVE 1 57 SEAL RETAINER 1
28 O-RING: 1B P20 1 58 SOCKET BOLT; M10X20 6
29 STOPPER 1 59 O-RING: 1B G75 1
30 SPRING 1 60 GUIDE 1
24
24-5
24.1.1.3 FUNCTION
(1) Structure of equipment
This pump is made up of piston pump and gear pump, the gear pump is directly connected to the
rear side of piston pump using coupling. The piston pump is separated into main body part and control
part.
(2) Explanation of construction and operation

1) Construction
(Figures in ( ) in text correspond to the figures in each construction drawing in Fig."Construction of
main part" and "Construction of regulator" of the next page.)
a. Swash plate type variable-displacement piston pump

The main body part is made up of rotary group, swash plate group and cover group.
The rotary group is made up of cylinder (9) integral with shaft (1) and 9 pistons AS (8) located
inside of cylinder (Shoe is caulked to piston). The shaft (1) is supported at both ends by
bearings (3) (17). And the piston AS (8) is pressed to cam (6) by return plate (7), retainer SPH
(15), and spring (16) to have smoothly slide on the cam.
The swash plate group is placed so that cam (6) slides on cradles (5) (14) smoothly attached on
housing (2) and works so as to keep the condition where cam (6) is always pressed to cradles
(5) (14) by hydraulic pressure and spring (16) force which exert on piston AS (8).
The cover group is made up of cover (18) having suction and delivery ports, port plate (10)
which is pressed to the edge of cylinder (9) by spring (13) force and hydraulic oil pressure which
act on bushings (12) (24), power piston (20) and rod (19) which are used to control the cam (6)
to the proper position, and piston RE (22) and rod RE (21) which are used to push back cam
(6) to the max. tilting side (Max. delivery side).
The control part is made up of link (77) which is used to feed back the movement of rod (39),
sleeve (36) and power piston (20) which work for various kinds of control to sleeve (36), spring 1
(30) and spring 2 (31) which is used to determine the power characteristics, and so on.
b. Constant delivery gear pump
NP8 is of single gear pump. The gear drive and gear driven in integral type of shaft and gear are
supported by bushings respectively. The casing is made up of body having outlet port and cover
front having inlet port.
The inlet (suction) port is located on the attaching side so as to be shared with piston pump.
24-6
2) Explanation of operation
a. Explanation of swash plate type axial piston pump operation

The piston pump is driven by sources like engine, and the engine rotates shaft (1) and then
rotates cylinder (9) connected to shaft (1) by the use of spline. Piston AS (8) placed in cylinder
(9) rotates with cylinder (9) and reciprocates because shoe and piston sphere section are
connected by the way like universal joint. Accordingly the suction stroke of oil is performed from
top dead point to bottom dead point of cam (6) and the delivery stroke of oil is performed from
bottom dead point to top dead point. And the oil leaked from each sliding section and the
clearance is returned to tank through drain port provided on cover (18). The led oil through inlet
port passes through passage "A" on the cover, passage "B" on port plate (10) having crescent
port which is used to switch suction and delivery by one rotation of pump and passage "C"
inside of cylinder (9), and is supplied to piston bore "D". And the delivery oil through cylinder
piston bore flows through passage "E" on the port plate (10) and passage "T" inside of bushing
(12) on cover (18), and then passes through passage "G" on cover (18) and is discharged through
outlet port.
The piston pump is operated as described above, but the delivery flow rate of hydraulic oil pump
is determined according to the rotation speed of shaft (1) and the angle of cam (6) tilted to the
axis.
24
24-7
Construction of main part
Construction of regulator
24-8
b. Explanation of gear pump operation

Gear pump in NP series is in type of external gear pump, and is of structure the drive gear and
driven gear engages in the casing and rotates.
When the drive gear is rotated through coupling by piston pump, oil in body suction port flows to
oil grooves of both drive and driven gears and is discharged through outlet port along to the
casing internal surface.
c. Explanation of piston pump control operation
1. Control function
This pump is equipped with the following functions.
3.1. Individual power control
3.2. Negative flow control
3.3. Back pressure compensation flow control
2. General principle for control (Refer to Items Fig. "Construction of regulator" to Fig. "Back pressure
compensation curve" of "Each control explanation".)
The swash plate type incorporated in this pump is of position control type which has the
displacement of rod (39) vary in proportion to the level of balance between hydraulic oil pressure
which exerts on rod (39) and spring force of power control springs (30) (31), tilts cam (6) through
the power piston which follows the displacement, and varies the pump delivery flow rate.
Section of gear pump 24
24-9
3. Explanation of pump operation
3.1. Power control (Control by self-delivery pressure)

The following explanation is given referring to the internal construction drawing shown in Fig. "Section
of gear pump".
In this condition, self-delivery pressure flows into control section and constantly exerts on the hatching
area. The characteristics between self-delivery pressure - flow rate (Pd-Q characteristics) by power
control is shown in Fig. "Power control, control part structural drawing".
When self-delivery pressure Pd is 1st turning point P1 or less shown in Fig. "Power control, control
part structural drawing", the hydraulic oil pressure which exerts on piston B (40) is lower than the set
load of spring 1 (30) and consequently as the passage connected to power piston (20) is not open the
self-delivery pressure is not led to power piston chamber and cam (6) is held in the set max. tilt
position by self-delivery pressure Pd which exerts on piston RE (22) and spring force of spring RE
(23) installed in piston RE chamber.
Power control, control part structural drawing
And when the self-delivery pressure is raised and is more than 1st turning point P1 shown in Fig.
"Power control, control part structural drawing", rod (39) moves leftward as shown in Fig. "Delivery
rate is decreasing" and the self-delivery pressure is led into power piston chamber. Because the
cross-sectional area of this power piston (20) is larger than the cross sectional area of piston RE
(22), power piston (20) resists the force of piston RE (22) and moves leftward. Accordingly the tilt
angle of cam (6) reduces and the pump delivery flow rate lowers too. On the other hand, since the
notch (I) of link (29) is fitted to the pin fixed on power piston (20), link (29) rotates taking "H as
fulcrum following the movement of power piston (20). Since "J" of sleeve (36) is fitted to pin (32)
fixed to link (29), sleeve (36) moves leftward according to the rotation of link (29).
24-10
Consequently power piston (20) and cam (6) stop to the position where sleeve (36) breaks the
passage connected to power piston chamber. And Pd-Q characteristics corresponds to P1~P2 shown in
Fig. "Pd-Q curve (Power control)" when spring force which exerts on rod (39) is only spring 1 (30),
and corresponds to P2~P3 when the force of both spring 1 (30) and spring 2 (31) exerts on rod (39).
Pi-Q curve
24
Back pressure compensation control, control drawing
24-11
Conversely, when the self-delivery pressure Pd is lowered from the high pressure to low pressure,
since the hydraulic pressure which exerts on piston B (40) is also lowered rod (39) is returned
rightward by spring force of spring 1 (30) (or springs 1 and 2), and consequently the passage
connected to power piston chamber is released to the tank circuit. Accordingly, the tilt angle of cam
(6) is increased by the hydraulic oil pressure which exerts on piston RE (22) and the spring force of
spring RE (23) inside of piston RE chamber, and accordingly the pump delivery flow rate increases.
The movement of cam (6) is transmitted to power piston (20) through rod PW (19) and power piston
(20) moves rightward. The movement of power piston (20) has link (29) rotate taking "H" as fulcrum
and has sleeve (36) move rightward. Accordingly cam (6) stops to the position where sleeve blocks
the passage connected to power piston chamber.
Delivery rate is increasing
As the above-mentioned, this piston pump moves rod (39) rightward and leftward in proportion to the
level of balance between hydraulic oil pressure which exerts on piston B (40) and the force of springs
(30) (31) for power setting, and consequently the power is approximately held constant by shifting the
tilt angle of cam (8).
24-12
3.2. Negative flow control

In negative flow control, the hydraulic pressure of piston U (42) which receives pilot pressure Pi
exerts on rod (39) through piston H (46) and piston (42). As pilot pressure Pi rises, rod (39) is
moved leftward by piston U (42). Since rod (39) moves to the position where it is balanced against
the total spring force of springs (30) (31) for power setting and spring (43) for negative flow control,
cam (6) makes tilt angle smaller and gets pump delivery flow rate reducing.
Negative flow control, control part structural drawing
The diagram shown in Fig. "Pi-Q curve" shows the characteristics of pilot pressure - flow rate (Pi-Q
curve) of pump, and proves that as pilot pressure Pi raises the flow rate lowers that is shows that it
is negative flow control. With this mechanism, the pump delivers the required flow by the input of
pilot pressure Pi suitable for the required operation resulting in saving the power.
24
Pi-Q curve
24-13
3.3. Back pressure compensation flow control

The back pressure compensation flow control is equipped with function which cancels the increase
and decrease (fluctuation) of pilot pressure Pi which changes according to the back pressure
produced on the return line of control valve. As shown in Fig. "Back pressure compensation control,
control drawing", hydraulic oil pressure which is led through back pressure compensation port exerts on
the annular area of piston H (46). This area is equivalent to the pressure receiving area of piston U,
therefore the force which is required to move the rod in rightward and leftward with piston U does
not change. As the pilot pressure Pi rises, piston U (48) is pushed leftward and when it becomes
more than the reaction of piston H (46), piston U (48) starts moving, and since rod (39) moves to the
position where it is balanced against the total spring force of springs (30) (31) for power setting and
spring (43) for negative flow control, cam (6) makes tilt angle smaller and gets pump delivery flow rate
reducing.
Back pressure compensation control, control drawing
24-14
The diagram shown in Fig. "Back pressure compensation curve" shows the characteristics of pilot
pressure - flow rate (Pi-Q curve) of back pressure compensation flow control, and with the back
pressure compensation function, Pi-Q characteristics is shifted to the extent of rise of back pressure
compensation pressure Pb toward the high pressure side. This function increases the back pressure
of return line during the work which requires returning large quantity of flow from actuator and pump
flow rate is reduced to prevent phenomenon the operating speed slows down.
Back pressure compensation curve
24
24-15
24.1.1.4 ADJUSTMENT OF PISTON PUMP

(The names for each part are depending on Fig. "Pump adjusting")
Using adjusting screw, the maximum flow rate and power control characteristic of pump (1st turning
point P1 and 2nd turning point) are adjustable.
(1) Maximum flow rate adjusting

Loosen hexagon nut and turn the lock screw to adjust the flow rate.
Theoretical flow rate changes about 6 cm3/rev per 1 turn of the lock screw.
(2) Input power adjusting
1. 1st turning point adjusting
Loosen the nut with the hexagon nut locked, and turn the hexagon nut to turn the sleeve together,
consequently pressure is adjustable. The pressure at 1st turning point is increased by turning the
sleeve clockwise. In this time, the stopper turns together, turn the stopper reversely to return to
the original position.
2. 2nd turning point adjusting
Loosen the hexagon nut with the nut locked, and turn the stopper to adjust the pressure. The
pressure at 2nd turning point is decreased by turning the stopper clockwise.
Pump adjusting
24-16
24.1.1.5 EXAMPLE OF TYPICAL CIRCUIT

(Power control, Negative flow control, Back pressure compensation control)
24
24-17
24.1.1.6 CONTROL CHART OF PUMP (PVC 80 RC12)

(1) Scheme drawing
(2) Negative flow control scheme drawing
24-18
(3) Negative flow control scheme drawing
24
24-19
24.1.2 CONTROL VALVE

24.1.2.1 SPECIFICATION
(1) General view and hydraulic ports
General view and hydraulic ports
24-20
TYPE: O-RING PORT

Tightening
Port size torque Port Name Description
N-m (lbf-ft)
a1~a8 Pilot port
b1~b8 Pilot port
Pi1 Boom lock valve release pilot port
Pi2 Arm lock valve release pilot port
PF1/4 30 (22)
Pr Back press. compensation port
Ps LS press. detection port
Dr2, Dr3 Drain port
Pn Negative control port
A1 Swing port (right)
B1 Swing port (left)
A2 Travel right port(forward)
B2 Travel right port(reverse)
A3 Travel left port(forward)
B3 Travel left port(reverse)
A5 Boom down port
PF1/2 120 (88.5) B5 Boom up port
A6 Bucket dump port
B6 Bucket digging port
A7 Arm out port
B7 Arm in port
A8 Option (Head)
B8 Option (Rod)
T1 Drain port
P Pump P port
PF3/4 160 (118)
R2 Swing motor supply port
PF1 255 (188) R1, R3 Tank port
(2) Specification
ITEM SPECIFICATION
PART No. YT30V00047F4
MODEL iK18-8505
RATED FLOW RATE 132 L/min (36 gal/min)
MAIN RELIEF VALVE SET PRESSURE 29.4 MPa (4270 psi)
OVERLOAD RELIEF VALVE SET PRESSURE
BOOM, BUCKET, ARM, OPTIO 32.9 MPa (4770 psi)
NDOZER 26.4 MPa (3830 psi)
24
24-21
(1) Control valve
Construction of control valve (1/5)
24-22
24
24-23
24-24
24
24-25
24-26
Tightening Tightening
torque No. PARTS Q'TY REMARKS torque No. PARTS Q'TY REMARKS
N-m (lbf-ft) N-m (lbf-ft)
1 HOUSING 1 30 (22.1) 45 SOCKET BOLT 4 M8X70

2 END COVER 1 15 (11.1) 46 PLUG 1
3 COVER 8 50 (36.9) 47 SOCKET BOLT 4 M10X50
4 COVER 8 13 (9.59) 48 SOCKET BOLT 32 M6X20
5 COVER ASSY 2 HOLDING V. 49 O-RING 16 A90
6 SELECTOR ASSY 1 N&B 50 O-RING 15 1B P8

100 (73.8) 7 FLOW CONTROL ASSY 1 51 O-RING 27 1B P18
60 (44.3) 8 RE-GENERATION ASSY 1 52 O-RING 2 1B P10
60 (44.3) 9 CHECK ASSY 5 53 O-RING 1 1B P14
10 PLUNGER T1 ASSY 1 54 O-RING 2 1B P22
11 PLUNGER M ASSY 2 60 (44.3) 55 CAP 6 PF1/2

12 PLUNGER D10 ASSY 1 20 (14.8) 56 CAP 11 PF1/8
13 PLUNGER B ASSY 1 40 (29.5) 57 CAP 1 PF3/8
14 PLUNGER C ASSY 1 58 O-RING 1 1B P22A
15 PLUNGER A1 ASSY 1 59 BUCKUP RING 1
16 PLUNGER D6 ASSY 1 60 O-RING 24 1B P11

17 FLANGE 1 61 BUCKUP RING 1
100 (73.8) 18 MAIN RELIEF ASSY 1 29.4MPa 62 O-RING 1 1B P20
(4270psi) 63 BUCKUP RING 15
64 GUIDE SP 8
60 (44.3) 19 OVERLOAD RELIEF 8 32.9MPa 65 SPRING 4

ASSY (4770psi) 66 SPACER 8
60 (44.3) 20 OVERLOAD RELIEF 2 26.4MPa 30 (22.1) 67 CAP PL 8
ASSY (3830psi) 68 SPACER 8
80 (59.0) 21 CAP 8 69 PLUNGER T 1
22 O-RING 18 70 PLUNGER M 2
23 SPRING 8 71 PLUNGER D10 1
24 CHECK 8 72 PLUNGER B 1
15 (11.1) 25 PLUG 2 73 PLUNGER C 1
26 SPOOL PC 1 74 PLUNGER A1 1
27 SPRING 3 75 PLUNGER D6 1
28 CHECK 3 76 CHECK 2
29 SPRING 3 80 (59.0) 77 CAP 2
20 (14.8) 30 CAP 3 78 SPRING 2
80 (59.0) 31 CAP 8 79 O-RING 2 1A P10
15 (11.1) 32 SOCKET BOLT 4 M6X15 80 BUCKUP RING 4

33 SPOOL PC 5 81 CAP 9 PF1/4
34 SPRING 1 82 O-RING 1 1B P21
35 SPRING 3 83 SPRING 4
36 PLUG ASSY 1 5 (3.69) 84 PLUG 5
37 PLUG ASSY 2 30 (22.1) 85 CHECK ASSY 1

38 PLUG ASSY 2 5 (3.69) 86 CHECK ASSY 1
39 PLUG 1 87 O-RING 2 A90
40 FILTER 2 88 SPOOL PC 1 BOOM
41 FILTER GUIDE 2 89 SPRING 1
42 SPRING 2 90 SPACER 2
24
43 POPPET 2 8 (5.9) 91 PLUG 2
30 (22.1) 44 SOCKET BOLT 8 M8X60 92 SPOOL PC 1 DOZER
24-27
(2) Detail of assembly pats

1. Main plunger
No. PARTS Q'TY No. PARTS Q'TY

1 PLUNGER 1 4 SPRING 1
2 SPRING GUIDE 1 5 SPACER 1
3 SPACER 1 6 PLUNGER CAP 1
2. Main relief valve
24-28
3. Selector valve
4. LS orifice
5. Load check valve
24
24-29
6. Holding valve

1 SOCKET BOLT 4 13 SPACER 1
2 COVER 1 14 SPRING 1
3 O-RING 1 15 CHECK 1
4 BACKUP RING 1 16 PLUG 1
5 SLEEVE 1 17 PLUG 1
6 O-RING 3 18 POPPET 1
7 BACKUP RING 1 19 SPRING 1
8 SPRING 1 20 O-RING 1
9 PISTON 1 21 POPPET 1
10 O-RING 1 22 SPRING 1
11 CAP 1 23 O-RING 1
12 CAP 1 24 CAP 1
24-30
7. Re-generation valve (BM, BKT)
8. Pressure compensator (Meter out) (DOZ, BM, BKT)
9. Flow control valve
24
24-31
10. Slow return check valve
11. Arm re-generation valve
12. LS check valve (SW, TRV, AM, Opt.)
24-32
13. LS orifice (SW, TRV, AM, OPT.)
14. Pressure compensator (Meter in) (SW, TRV, AM, Opt.)
15. Over load relief valve

1 O-RING 1 11 ADJUSTING SCREW 1
2 BACKUP RING 1 12 NUT 1
3 PISTON 1 13 CAP 1
4 BACKUP RING 1 14 SPRING 1
5 O-RING 1 15 PILOT POPPET 1
6 SPRING 1 16 SLEEVE 1
7 SPRING 1 17 PILOT SEAT 1
8 O-RING 1 18 O-RING 1 24
9 O-RING 1 19 MAIN POPPET 1
10 SPRING GUIDE 1 20 MAIN SEAT 1
24-33
24.1.2.3 FUNCTION (Meter OUT pressure compensation type)

(1) Neutral position
Delivered oil from pump flows through P parallel passage to P tandem passage from P port via control
orifice (Pump control pressure generates here), and the oil flows into tank line. The pressure of LS
signal line is equal to tank pressure. And P port pressure acts on a lower part of flow control spool,
and this time, the flow control spool opens fully.
Pressure signal generated at negative control orifice is given feedback to the pump regulator from Pn
port, consequently, the pump delivery rate is limited to minimum flow rate.
24-34
Neutral position
24
24-35
(2) Single operation

The delivery oil from pump passes through Meter-IN orifice of main plunger from P port, and opens
load check valve, and then it flows into cylinder port (B).
The flow control valve is controlled by the pressure of front and rear Meter-IN orifice (equivalent to
spring force). The oil which is passed through float control valve flows through negative control orifice
and the pump delivers oil rate which corresponds to the plunger stroke which has received the
generated pressure signal. The return oil from cylinder (A) passes through periphery of pressure
compensation valve and flows into tank.
24-36
Single operation
24
24-37
(3) Combined operation

The highest LS (Load Sensing) pressure exerts on flow control valve. Simultaneously, the pressure
exerts on pressure compensation valve spool of other actuator, and throttles the flow to tank
(Meter-OUT line).
The flow control valve is controlled by P port pressure and the highest LS pressure.
The oil which has passed through flow control valve flows through negative control orifice and the
pump delivers oil rate which corresponds to the plunger stroke which has received the produced
pressure signal.
The delivery oil from pump is distributed according to each plunger stroke (Opening of Meter-IN orifice).
Because SUB BLEED-OFF is provided, the uninterrupted operation is possible without stopping the
movement of light load actuator.
24-38
Combined operation
24
24-39
(4) Explanation of operation about each part

1) Main plunger
Meter-OUT pressure compensation type
a. Neutral position
The main plunger is set to neutral position by spring. Each Meter-IN and Meter-OUT orifice is
blocked.
Since the sensing core is connected to tank passage, LS signal corresponds to the tank pressure.
b. Plunger operation (Pilot port b: Under pressure)

The main plunger moves leftward and the delivery oil from pump passes through Meter-IN orifice
and opens load check valve through sensing core, and flows to cylinder port B.
The pressure oil of the downstream from Meter-IN orifice opens LS select check valve of
pressure compensation valve and flows into LS signal line.
The return oil from cylinder port A passes through Meter-OUT orifice and flows into tank passage.
* Pilot port a: Under pressure, A and B reverse in flow direction.
24-40
Meter-IN pressure compensation type

a. Neutral position
The main plunger is set to neutral position by spring. Each Meter-IN and Meter-OUT orifice is
blocked. (In only travel operation: A and B-T connected)
b. Plunger operation (Pilot port b: Under pressure)

The main plunger moves leftward and the delivery oil from pump passes through Meter-IN orifice
and opens load check valve through sensing core and high pressure passage, and flows to
cylinder port B.
The pressure oil of the downstream from Meter-IN orifice opens LS select check valve of
pressure compensation valve and flows into LS signal line.
The return oil from cylinder port a: The flowing direction is reversed when this port is pressurized.
* Pilot port a: Under pressure, A and B reverse in flow direction.
24
24-41
2) Main relief valve

a. The delivery oil from pump passes through orifice 2 of main poppet A and flows into chamber 3.
The main poppet A is securely seated in d1 > d2 condition.
b. When the pressure reaches to the set pressure by the reaction force against spring C, pilot
poppet B opens and the oil passes through the opening on the passage 4 and flows into tank
passage.
c. The oil flow is formed and the pressure drops at front and rear of orifice 2, and main poppet
opens in condition of pressure of "Chamber 1 X d2 area > pressure of chamber 3 X d1 area".
And the pressure oil flows into tank passage and limits the circuit pressure to constant value.
24-42
3) Recirculation valve 1 Boom, Bucket

a. Plunger operation (Pilot port b: Under pressure)
The return oil from cylinder port A passes through Meter-OUT orifice and flows into tank circuit
through sub tank passage.
When the pressure of high pressure supply passage is higher than the pressure of sub tank
passage, check valve C is securely seated. But when the pressure of high pressure supply
passage drops and comes down to the pressure of sub tank passage or less, check valve C is
opened by the differential pressure and the oil is fed into port B of cylinder again through high
pressure supply passage and consequently cavitation is prevented from occurring and the actuator
speed is maintained.
* Pilot port a: Under pressure, A and B reverses in flow direction.
24
24-43
4) Pressure compensation valve (Dozer, Boom, Bucket)

a. In single operation
The pressure of sensing core (Pressure oil of the downstream from Meter-IN orifice) opens LS
select check valve inside of compensation valve spool and flows into LS signal line.
The compensation valve spool is pushed to lower position by the spring force of chamber 1 and
therefore the opening between sub tank passage and tank passage is maximized.
b. In combined operation (In light load section)

When Max. LS pressure (Max. load pressure in other section) flows into chamber 2, LS select
check valve closes, and compensation valve spool moves upward and controls the opening
between sub tank passage and tank passage.
The compensation valve spool is held so that the pressure of chamber 1 and chamber 2 is equal.
The delivery oil from pump is distributed to each section regardless of each load pressure.
24-44
5) Load holding valve

The explanation is given with boom load holding valve.
a. At plunger neutral position (Pi1 pilot signal: OFF)

Piston A and poppet B are placed to the position shown in the figure by spring force, and
passage 5 and 6 are blocked by poppet B.
Since chamber 1 is therefore connected to chamber 2 through orifice 4, the pressure is
equivalent to the pressure (Ph). Then poppet D is securely seated in d1 > d2 condition and the
flow between chamber 2 and chamber 3 is completely blocked.
24
24-45
b. In plunger operation
1. Boom up operation (Pv > Ph) (Pi1 pilot signal: OFF)

The plunger moves leftward and the oil in supply passage flows into chamber 3. Since the
pressure of chamber 1 is connected to chamber 2 through orifice 4, the pressure is equivalent to
the pressure (Ph) and then poppet D opens and the delivery oil from pump is supplied to the
cylinder head side through high pressure supply passage.
24-46
2. Boom down operation (Ph > Pv) (Pi1 pilot signal: ON)
The plunger moves rightward and is connected to chamber 3 tank passage. And pilot signal
pressure (Pi1) exerts on piston A and moves poppet B leftward, and consequently the passage 5
and 6 are connected.
Chamber 1 is connected to tank passage through passages 5 to 6 and check valve C, and the
pressure therefore drops and then pressure (Pb) exerts on the differential area of d1 and d2 and
opens poppet D and consequently the return oil from the head side flows into tank passage.
6) Flow control valve

a. The pressure oil flows into chamber 1 through pump port. The tank pressure or LS signal
pressure flows into chamber 4.
24
24-47
b. Main plunger: Neutral position

P port pressure exerts on the right end of spool B. Since chamber 4 is of tank pressure, spool B
moves leftward and the passages 2 and 3 of sleeve A are fully open.
c. Main plunger: In operation

LS signal pressure is load pressure (PLS). Spool B receives P port pressure and load pressure
(PLS) and moves rightward and controls the opening of passage 3.
A part of oil led through pump port passes through passage 3, flows to negative control orifice
and controls the pump delivery rate.
24-48
7) Recirculation valve
a. The plunger moves leftward by operating arm plunger to the arm-in side, the delivery oil from
pump opens load check valve and is supplied to the cylinder head side through supply passage.
The return oil from the rod side opens load holding valve poppet and flows into tank passage
through back pressure check valve, but the pressure is raised by back pressure check valve and
a part of oil opens recirculation check valve and is supplied to the head side again.
24
24-49
8) Pressure compensation valve (Slewing, Travel, Arm, OPT.)

a. In single operation
The pressure of sensing core (Pressure of downstream from Meter-IN orifice) opens LS select
check valve and flows into LS signal line.
The compensation valve spool is set to the right end by the spring force of chamber 1 and
therefore is fully open to the sensing core and high pressure supply passage.
24-50
b. In combined operation (In light load section)

When Max. LS pressure (Max. load pressure in other section) flows into chamber 2, LS select
check valve closes and compensation valve spool moves leftward and controls the opening
between sensing core and high pressure supply passage.
The compensation valve spool is held so that the pressure of chamber 1 and chamber 2 is equal.
The delivery oil from pump is distributed to each section regardless of each load pressure.
9) Overload relief valve

a. Overload relief valve operation
1. The delivery oil from cylinder port passes through orifice 2 of piston A and flows into chamber 3.
The main poppet B is securely seated in d1 > d2 condition.
24
24-51
2. When the oil pressure reaches to the set pressure with the reaction force of spring D, pilot poppet
C opens and the oil passes through passages 4 and 5 and flows into tank passage.
3. The oil flow is formed and the pressure drops at front and rear of orifice 2 of piston A, and
consequently piston A moves rightward and is seated to the top end of pilot poppet C.
The oil in chamber 1 passes through orifice 6, passages 4 and 5 and flows into tank passage.
24-52
4. The oil pressure drops at front and rear of orifice 6 of piston A, and main poppet B opens in
condition of pressure of chamber 1 X d2 area > pressure of chamber 3 X d1 area, and the
pressure oil flows into tank passage and protects actuator from damaging.
b. In make-up operation
Since main poppet B is in d1 > d2 condition, the cylinder port pressure is usually higher than the
tank pressure and then the piston is securely seated.
When the pressure of cylinder port drops (close to negative pressure) and cylinder port pressure is
lower than tank pressure, main poppet B receives tank pressure corresponding to the differential
area and opens and then flows to cylinder port through tank passage resulting in preventing
cavitation.
24
24-53
This page is blank for editing convenience.
24-54
24.1.3 PILOT VALVE (ATT)

24.1.3.1 OUTLINE
(1) Outside view
24
24-55
Pilot valve (ATT)
Tightening torque Tightening torque

No. NAME Q'TY No. NAME Q'TY
101 Casing 1 *218-1 Seat 2
151 Plate 1 *218-2 Seat 2
201-1 Spool 2 221 Spring 4
201-2 Spool 2 241-1 Spring 2
211 Plug 4 241-2 Spring 2
212 Push rod 4 *246 Spring 4
213 Seal 4 47.1 (34.7) 301 Joint: M14 1
214 O-ring: 1B P20 4 302 Circular plate 1
216-1 Spring seat 2 68.6 (50.6) 312 Adjust nut: M14 1
216-2 Spring seat 2 501 Boots 1
217 Washer 2 (Shim) 4
Note) The parts marked * may not be equipped depending on valve type.
24-56
24.1.3.3 OPERATION
(1) Lever in neutral (See right Fig.)
The action of spring (509) (for secondary
pressure setting) that determines the output
pressure of the pilot valve does not act upon
spool (201). Therefore, spool (201) (for return)
is pushed up by spring (221) [spring seat
(216)]. The output ports (2,4) connect with the
T port. The result is that the output pressure
is equal to the tank pressure.
Lever in neutral
(2) When the pilot lever is tilted (See right Fig.)

When the lever is tilted and the push rod
(511) strokes, the spool (201) [spring seat
(216)] moves downward to make the port P to
connect with the port 2, 4, with the result that
the oil of the pilot pump flows to the port 2 ,4
to produce a pressure.
When the lever is tilted
(3) Lever held (See right Fig.)

When the pressure at ports (2,4) rises to a
level equivalent to the action of spring (509)
that is set by tilting the lever, the hydraulic
pressure balances the spring action. When the
pressure of ports (2,4) rises above a set
value, ports (2,4) and the P port close while
ports (2,4) and the T port open. When the
pressure at ports (2,4) falls below a set value,
ports (2,4) and the P port open while ports
(2,4) and the T port close. Thus the secondary 24
pressure is kept constant.
When the lever is held
24-57
(4) Operation in the area where the tilting angle of the lever is large.
(varies with the model)
If the lever is inclined beyond a certain angle on certain models, the top end of the spool contacts the
bottom of the bore of the push rod. This keeps the output pressure connected with the P port
pressure.
Furthermore, on a model in which a spring seat and a spring are built in the push rod, the bottom of
the bore of the push rod contacts the spring if the lever is turned beyond a certain angle. This causes
the secondary pressure gradient to change by the spring action. Thereafter, the bottom of the bore of
the push rod contacts the top end of the spring seat, keeping the output pressure connected with the
P port.
24-58
24.1.4 PILOT VALVE (TRAVEL)

24.1.4.1 OUTLINE
(1) General view
(2) Specifications
Parts No. YN30V00070F2
Type PVD6PC4017A
Max.primary pressure 6.9MPa (1000 psi)
Rated flow 10 L/min (2.64 gal/min)
Weight 3.9 kg (8.6 lbs)
(3) Performance characteristics
24
24-59
Assembly view of pilot valve (travel)
torque No. Parts Q'ty torque No. Parts Q'ty
101 CASING 1 29.4 (21.7) 251 RO PLUG 3
102 CASING (Damper) 1 6.9 (5.1) 252 PLUG 6
191 SEAT 1 2 11.8 (8.7) 253 RO PLUG 2
192 SEAT 2 2 261 O-RING 3
193 BUSHING 2 2 8.8 (6.5) 271 CAPSCREW 4
194 BALL 2 301 SPOOL 4
201 COVER 2 311 SPRING SEAT 4
202 PLUG 4 313 WASHER 4
203 GREASE CUP 4 324 SPRING 4
210 SEAL 4 335 SPRING 4
212 O-RING 4 413 CAM SHAFT 2
213 O-RING 4 414 BUSHING 4
214 PUSH ROD 4 420 CAM 2
217 SHIM 4 471 BALL 4
218 SPRING SEAT 4 6.9 (5.1) 472 LOCK NUT 2
224 PISTON 4 501 BOOTS 2
225 BALL 12
24-60
24.1.4.2 FUNCTION
1. Reducing valve
(1) Neutral (See right Fig.)
Spool (301) is pushed up by spring (335)
(for return) via spring seat (311) and
washer (215) and is located in the neutral
position as shown in the cross-sectional
view. Therefore, since the output port
connects only with port T by the spool
select function, the pressures at output
ports 1, 2 are equal to that of port T.
(2) The control of the remote control valve is

tilted from its neutral (See right Fig.)
If cam (420) is rotated clockwise in the
cross-sectional view, push rod (214) on port
1 is pushed down. This moves the spool
down via washer 1, spring seat (for
secondary pressure setting), spring (324),
washer 2 (217), and washer 3 (313) and
connects port P with port 1. The oil
supplied by the pilot pump runs to port 1
and generates pressure.
If the control lever (or pedal) is inclined
and when the pressure at port 1 rises to
a level equivalent to the action of the
spring that sets the secondary pressure, the
hydraulic pressure acting on the spool
balances the spring action, thereby
keeping the output pressure at port 1
constant. The spool at port 2 is held
neutral ; the oil returning from the control
valve is discharged via port T.
On some specifications, the push rod 24
comes in direct contact with the top of the
spool in the neighborhood of the maximum
angle of the control. This pushes in the
spool forcibly which connects port P with
the output port and makes the pressures at
both ports equal.
24-61
2. Damping mechanism of the control

(1) Neutral
The push rod is pushed up by springs (336) via piston (224) (damping) and is located as shown
in the cross-sectional view.
(2) The control is inclined from its neutral position :
[Refer to the functional explanation (1) of damping]
If the cam is turned clockwise in the cross-sectional view, the push rod on the port 1 side is
pushed down which brings the piston down.
On that occasion, the oil in the damping piston chamber is discharged through the orifice. The
pressure then generated creates a damping force.
In the meantime, the push rod on the port 2 side moves up by the damping spring via the piston.
On that occasion, the oil in the tank chamber is sucked into the damping piston chamber through
the ball checks (3 places) that consists of bushing (223) and ball (225). The oil outside of the
piston chamber gets out of the path to port T, from the top end of the casing.
24-62
(3) The control lever (or pedal) is inclined from its maximum angle to its opposite side :
[Refer to the functional explanation (2) of damping.]
On the cross-sectional drawing, if the cam is tilted in its full clockwise direction and then turned
counterclockwise, the push rod on the port 2 side is pushed down. This moves the piston down.
On that occasion, the oil in the damping piston chamber is discharged from the orifice of the
piston. The pressure then generated creates a damping force.
In the meantime, the push rod on the port 1 side moves spring (335) (for return) and damping
spring (336) upwards.
The oil in the tank chamber is sucked into the damping piston chamber through the ball checks (3
places) consisting of a bushing and a ball. The oil outside of the piston chamber gets out from
the top end of the casing to the path that leads to the tank port.
That is to say, the mechanism is so constructed that damping force acts on any tilting operations
i.e. from neutral to full tilting or from full tilting to neutral.
24
24-63
24.1.5 SWING MOTOR UNIT

24.1.5.1 SPECIFICATIONS
(1) General view
General view of swing motor unit
24-64
(2) Specifications
Item Specifications
Swing unit YT15V00015F1 SG025E-142
Type & Part No. Motor YT15V00016F1 MFB40-330
Reduction unit YT32W00006F1 RG025S-155-58
Working pressure MPa (psi) 24.5 (3360)
Reduction ratio 1:15.54
Output torque kN-m (lbf-ft) 2.32 (3360) at 24.5 MPa (3360 psi)
Braking torque N-m (lbf-ft) 185 (1.4)
Brake release pressure MPa (psi) 2.0 (280), Allowable 3.9 (570)
The rotating direction (as seen from the shaft end) A port in : Clockwise, B port in : Counterclockwise
Weight (Including reduction unit) kg (lbs) 67 (148)
Reduction unit lubricate oil Nisseki gearlube SP90 : 1.5L (0.40 gal)
Grease Shell alvania EP2 : 150cc (9.15 cu-in)
24.1.5.2 EXPLANATION OF CONSTRUCTION

(1) The rotary group of the swing motor
consists of a cylinder (M-19) which is
integral with the drive shaft and seven
piston assy (M-21) arranged in the cylinder
bores. The cylinder (M-19) is supported by
bearings (M-1) (M-6) on both ends.
Each piston assy (M-21) is guided by a
return plate (M-22) and retaining spring
(M-20) so as to slide smoothly on the
cam plate (M-23).
The balance plate (M-10) is forced against
the end of the cylinder by the force of the
disc spring (M-15) and the hydraulic force
acting on the bushing (M-14).
A mechanical brake is installed between the
cylinder exterior and the housing (M-26).
A relief valve to cushion hydraulic shock
and a backup valve to prevent cavitation
are built in to the cover (M-39).
(2) The reduction gear system consists of two
stage planetary gears. The system
decelerates highspeed rotary motion of the
swing motor and coverts it to low-speed
large-torque motion in order to rotate the
pinion shaft. 24
24-65
(1) Swing motor
Swing motor
24-66
No. Parts Q'ty No. Parts Q'ty

M-1 TAPER ROLLER BEARING 1 M-22 RETURN PLATE 1
M-3 FRICTION PLATE 2 M-23 CAM PLATE 1
M-4 SEPARATOR PLATE 2 M-24 LEVEL GAUGE 1
M-5 SNAP RING 1 M-25 O-RING 1
M-6 NEEDLE BEARING 1 M-26 HOUSING 1
M-7 O-RING 1 M-27 COLLAR 1
M-8 O-RING 1 M-28 OIL SEAL 1
M-9 O-RING 1 M-30 BACKUP RING 2
M-10 BALANCE PLATE 1 M-31 O-RING : 1B P21 2
M-11 PISTON 2 M-33 BACKUP RING 2
M-12 TEFLON RING 2 M-34 O-RING : 1B P26 2
M-13 PLUG : PT 1/4 2 M-35 PARALLEL PIN 2
M-14 BUSHING 4 M-36 PLUG : PF 3/8 1
M-15 SCROWAVE 4 M-37 O-RING : 1B P14 1
M-16 TEFLON RING 4 M-38 SOCKET BOLT : M12 X 30 4
M-17 SPRING 13 M-39 COVER 1
M-18 PISTON 1 M-40 PLUG 1
M-19 CYLINDER 1 70 RELIEF VALVE ASSY 2
M-20 SUPPORT SPRING 1 100 BY-PASS VALVE ASSY 2
M-21 PISTON ASSY 7
24
24-67
1. Relief & check valve assy (70)
Detail of Relief & check valve assy

RELIEF& CHECK VALVE
70 2 82 SEAT 2
ASSY
71 LOCK NUT 2 83 POPPET 2
72 CAP 2 84 SPRING 2
76 BACKUP RING 2 85 O-RING 2
77 O-RING : 1B P26 2 86 SHIM 2
78 SPRING 2 87 PISTON 2
79 BUSHING 2 88 SLEEVE 2
80 CHECK 2 89 O-RING 2
81 SLEEVE 2 90 CAP 2
2. By-pass valve assy (100)
Detail of by-pass valve assy (swing shockless valve)

100 BY-PASS VALVE ASSY 2 106 O-RING : 1B P21 2
101 SEAT 2 107 BACKUP RING 2
102 SLEEVE 2 108 CAP 2
103 POPPET 2 109 SPRING 2
104 BACKUP RING 2 110 POPPET 2
105 O-RING : 1B P14 2 111 SPRING 2
24-68
(2) Swing reduction unit
Swing reduction unit

R-1 PINION SHAFT 1 R-13 HOLDER 1 ASSY 1
R-2 COLLAR 1 R-14 SOCKET BOLT : M12 X 95 6
R-3 PLATE 1 R-15 HOLDER 2 ASSY 1
R-4 TAPER ROLLER BEARING 1 R-16 NEEDLE BEARING 6
R-5 GEAR CASE 1 R-17 SHAFT 2 3
R-6 PLUG : PT1/8 1 R-18 SPUR GEAR 5 3
R-7 OIL SEAL 1 R-19 THRUST PLATE 2 6
R-8 TAPER ROLLER BEARING 1 R-20 SPRING PIN : 8 X 15 3
R-9 PIN 2 R-21 HOLDER 2 1
24
R-10 RING GEAR 1 R-22 COLLAR 2
R-11 SPUR GEAR 4 1 R-23 RELIEF NIPPLE 1
R-12 SUN GEAR 1
24-69
24.1.5.4 OPERATION
(1) Swing motor
The pressure oil fed by the pump via the control valve, etc. enters the motor through port A (or port
B) installed on cover (M-39), and is discharged from port B (or port A).
Also the oil leaking through the sliding section or clearance returns to the tank through drain port Dr
installed on cover (M-39).
The pressure oil fed to port A goes through passage (b) inside of cover (M-39) and to the passage on
bushing (M-11) section installed cover, then is fed to piston bore (f) on the cylinder through balance
plate (M-10) passage (b) which contains crescent shaped port switching supply and discharge by 180
degrees of core rotation of motor, and cylinder (M-19) passage (e).
The pressure oil exerts on piston assy (M-21), then the piston assy is pushed against cam plate
(M-23) through a part of the shoe. Since the shoe sliding surface of cam plate (M-23) is inclined at a
uniform angle, the pushing force of piston assy (M-21) on which pressure oil is exerted is converted
into sliding power for the shoe on the swash plate.
In addition, the shoe bulb is similarly joined to universal joint. As a result, the shoe sliding power on
the swash plate is converted into rotating power through piston assy (M-21) and cylinder assy (M-19)
and transmitted to the motor output shaft section.
In this way, every piston assy (M-21) receives the pressure oil within the stroke from top dead point to
bottom dead point on a grade, the oil pressure is converted to rotating power to rotate cylinder assy
(M-19), resulting in discharging oil in the stroke from bottom dead end and top dead point.
The discharge line function in reverse of the supply line, and the oil is discharged from port B.
As described above, the hydraulic motor is operated, and the output torque of hydraulic motor is
determined by oil pressure, and speed of revolution by supply flow rate.
(2) Parking brake

Separator plate (M-4) is fitted to the external section of cylinder assy (M-19) with spline.
Friction plate (M-3) is fitted to housing (M-26).
When the primary pilot pressure of brake release port is Zero, brake piston (M-18) locks the cylinder
(M-19) (output shaft) which is rotated by the force of the spring (M-17) pushing separator plate and
friction plate.
Conversely, when pressure of 1.96 to 3.92MPa (280 to 570psi) exerted on the brake relief port, brake
piston power exceeds the force of spring and strokes to the contact with cover end. Then space is
generated between mating parts, and the mechanical brake released.
24-70
24
24-71
(3) Relief valve

1. Starting
With operation of the lever, the oil fed to port A at first escapes and is discharged to port B
without obtaining regular revolution because the force of inertia of the upper structure is larger.
The hydraulic oil from port A to passage (i) of relief valve, opens poppet (83), and is discharged
to port B.
2. Braking (Cushion)
By returning the lever to neutral position, the return circuit of motor discharge oil close, and
immediately after this operation, the motor is rotated by the force of inertia resulting in pumping
function, and the oil is sucked from port A and discharged to port B side. Then, since the return
circuit of the control valve is closed, the pressure of port B is raised.
The raised pressure of port B opposes the spring (84-B) force and opens poppet (83-B), and
check valve (80-B) through passage (g) (h), and flows into passage (c). The movement stops
while absorbing the force of inertia in this process.
In the above-mentioned process of pressure increase, the oil at port B enters the piston (L)
chamber past the small orifice of poppet (83-A), and causes the piston (87) to move till it hits
the cap (90). In this period, the poppet (83-A) is already open, so that the cushion relief action
operates first at a little lower pressure.
3. 2-step relief at braking
(shockless relief action)
The increased pressure at port B enters the piston chamber (L) past the path (t) of the poppet
(83-B). The poppet begins to move to the right slowly by the throttling effect of the inlet path and
stops when it hits the shoulder J of piston (87) and the stopper K of sleeve (88). It pushes the
spring (84-B), acting as 2-step relief that rises to a specified pressure. This absorbs impacts at
starts and stops.
Detail of relief valve (70)
(4) Make-up valve

1. Operation in half lever position
(When cushion relief valve does not function.)
After accelerating slewing of the upper structure, when the speed is being reduced by half-lever
with the function of control valve, the supply flow rate from pump to port A is lowered. But if the
upper structure is slewed at a comparatively high speed, the pressure in the (C) section is
lowered to negative pressure making lubrication necessary. However, when the pressure of port B
is equal to or lower than the working pressure of cushion relief valve the all oil of (C) section led
through port B is discharged to the control valve.
As a result, the flow rate from the control valve (Since the valve is in the half-lever position, the
flow rate from pump is limited.) does not satisfy the specified oil quantity. To prevent this, the
make-up check valve is installed to supply necessary oil into the (C) section.
24-72
2. Braking
(When cushion relief valve is functioned)
When the lever is moved to neutral position rapidly as described in item 1), the pump does not
supply oil to port A, but the upper structure is slewed by the force of inertia. In this case, the
cushion relief valve on port B side functions, and the oil from relief valve goes through the
passage (g) (h) and opens make-up check (80) valve on the port A side to flow into passage (b)
(c). But the oil quantity is insufficient due to the leakage.
Therefore oil opens make-up check valve (80) through the make-up port, and flows into passage
(b) (c) to prevent cavitation.
(5) By-pass valve (Swing shockless valve)

1. Accelerating
At the moment of swing operation, the high pressure oil in the "A" side flows instantly into the "B"
side instantly, but the high pressure oil enters the chamber on the back side of poppet A
simultaneously. Then poppet A moves rightward, resulting in the poppet A "Close" condition
shown in below Fig.
2. Braking
When braking, the pressure oil of B side is raised to high pressure, and the high pressure oil is
bypassed from B side to A side, but the high pressure oil enters the chamber on the back side of
poppet B simultaneously.
3. Reverse rotation
After stopping the swing of the upper structure, the motor is reverse-rotated by high pressure on
the B side. But while the motor is rotated inversely, the high pressure oil is by-pass from A side
to B side to hold the reverse rotation to one rotation or less, protecting the generation of
reverse-rotation pressure.
Poppet A "Open"
24
Detail of poppet
24-73
(6) Swing reduction gear

The power of the swing motor output shaft is transmitted to spur gear 4 (R-11) on the 2nd stage
through sun gear (R-12) on the 1st stage and holder assy (R-13).
Similarly, the power is transmitted to pinion shaft (R-1) through spur gear 4 (R-11) on the 2nd stage
and holder assy 2 (R-15). The pinion shaft is supported by two bearing (R-4) (R-8) in gear case (R-5).
In addition, oil seal is installed at the center of gear case (R-5) to protect the bearing on the pinion
shaft side of which the load condition is difficult from the gear friction power, and the A chamber side
is lubricated by oil in the gear case, and the B chamber is lubricated by the grease sealed inside.
Function of reduction unit
24-74
24.1.6 TRAVEL MOTOR

(1) General view
24.1.6.2 HYDRAULIC CIRCUIT
24
24-75
24.1.6.3 SPECIFICATION
TYPE SGM - 04D - S - 09KL
TOTAL EQUIVALENT DISPLACEMENT cc/rev (cu-in/rev) 2205/1177 (134.5/71.8)
DISPLACEMENT OF MOTOR cc/rev (cu-in/rev) 40.2/21.5 (2.45/1.31)
REDUCTION GEAR RATIO 54.8
8770 (6468) or more, at 29.4MPa, 15L/min
MAX. OUTPUT TORQUE N-m (lbf-ft)
(at 4263 psi, 4.0 gal/min)
Low 28.4 or more, at 9.8MPa, 66L/min
MAXIMUM SPEED min-1
High 53.3 or more, at 4.9MPa, 66L/min
PARKING BRAKE TORQUE N-m (lbf-ft) 109 (80.4) or more (at motor shaft)
PARKING BRAKE RELEASE PRESSURE MPa (psi) 0.8 (116) or less
EXTERNAL PILOT PRESSURE 0.49 (71) or less

THRESHOLD TO DECIDE AUTOMATIC (Low speed mode fixed)
MPa (psi)
2-SPEED SHIFT MODE / LOW SPEED 1.96 (284) or more
FIXED MODE (Auto 2-speed shift mode)
Supposed to shift-change Hi-->Lo
AUTOMATIC 2-SPEED SHIFT THRESHOLD at 25.9 (3756) when pp=3.5 (508)
MPa (psi)
PRESSURE Supposed to shift-change Lo-->Hi
at 25.1 (3640) when pp=3.5 (508)
LUBLICATING OIL FOR GEARS SAE 30 class CD
ISO VG30, VG46, VG68
HYDRAULIC OIL
Wear resistant type hydraulic oil
WEIGHT kg (lbs) 88 (194)
24-76
(1) Structure of travel unit
24
24-77
(2) Parts list

1 TRAVEL GEAR ASSY 1 14 SPRING 1
1-1 CASING BODY 1 15 SPRING 1
1-2 FLOATING SEAL 1 16 STEEL BALL 2
1-3 BALL BEARING 2 17 PIN 3
1-4 RING NUT 1 18 SNAP RING 1
1-5 CASING GEAR 1 19 SPRING PIN 1
1-6 SUN GEAR A 1 20 BRAKE PISTON 1
1-7 PLANETARY GEAR A 3 21 FRICTION PLATE 2
1-8 NEEDLE BEARING A 3 22 STEEL PLATE 2
1-9 CARRIER 1 23 SPRING 1
1-10 SUN GEAR B 1 24 PLATE 1
1-11 PLANETARY GEAR B 4 25 PLUG 2
1-12 BUSHING 4 26 POPPET 2
1-13 NEEDLE BEARING B 4 27 SPRING 2
1-15 THRUST PLATE 2 1 28 O-RING 2
1-17 THRUST PLATE 4 4 31 BACK UP RING 1
1-18 SCREW 8 32 O-RING 1
1-19 WASHER 1 33 BACK UP RING 1
1-20 PARALLEL PIN 1 34 O-RING 1
1-21 COVER 1 41 PIN 2
1-22 SPRING WASHER 12 42 BOLT 8
1-23 BOLT 12 43 MOTOR COVER 1
1-24 PLUG 2 44 SPOOL ASSY 1
1-25 O-RING 2 44-1 SPOOL (LL) 1
2 SHAFT 1 44-2 ORIFICE 2
3 CYLINDER BARREL 1 45 PUSHER 2
4 BALL RETAINER 1 46 SPRING 2
5 RETAINER 1 47 COVER 2
6 CAM 1 48 O-RING 2
7 PISTON ASSY 9 50 ORIFICE 1
7-1 PISTON 9 51 SPOOL 1
7-2 SLIPPER 9 56 ORIFICE 1
8 VALVE PLATE 1 57 STEEL BALL 2
9 PLATE 1 58 PLUG 2
10 PISTON ASSY 1 59 O-RING 4
10-1 PISTON 1 60 RELIEF VALVE ASSY 2
10-2 PUSHER 1 60-1 BODY 2
11 BALL BEARING 1 60-2 POPPET 2
12 BALL BEARING 1 60-3 ROD 2
13 OIL SEAL 1 60-4 SEAT 2
24-78

60-5 PISTON 2 63 PLUG 7
60-7 NUT CAP 2 65 PLUG 3
60-8 SPRING 2 67 NAME PLATE 1
60-11 O-RING 2 68 RIVET 2
60-12 O-RING 2 73 SPRING 1
60-13 O-RING 2 74 PLUG 2
60-15 BACK UP RING 2 75 O-RING 1
60-16 BACK UP RING 4 80 PLUG 1
61 PLUG 2 81 O-RING 1
62 O-RING 2
24
24-79
(3) Outline of travel unit

Travel unit is composed of 3 main parts and each part has the following function respectively.
1. Hydraulic motor
1-1. Rotating function
1-2. Speed change function
1-3. Parking brake function
2. Brake valve
2-1. Counter balance valve function
2-2. Cross relief valve function
2-3. Automatic speed change function
3. Reduction gear
3-1. Reduction function
3-2. Final power output function
24-80
1. Hydraulic motor part
Hydraulic motor has the following 3 functions.
1-1. Rotating function

This motor generates the rotary action and the rotary torque by high pressured oil.
And this rotary action and torque are transmitted to reduction gear part.
1-2. 2 Speed change function

The speed of this motor is switched from low speed to high speed and from high speed to low
speed by changing displacement per 1 rotation of the motor.
1-3. Parking brake function 24

When high pressured oil does not enter into the motor, and the motor does not rotate, the parking
brake is actuated automatically.
When high pressured oil enters into the motor, and the motor rotates, the parking brake is released
automatically.
24-81
1-1. Rotation function

When high pressured oil is supplied to left port
of motor, oil passes through valve plate and
flows into cylinder barrel. The high pressured oil
pushes piston leftward. The piston shifted to the
left position and rotates cylinder barrel while
sliding on the cam surface.
The shaft is connected to barrel and sun gear
(A) is connected to the shaft. Consequently
the rotation is transmitted through the rotation of
sun gear (A) as shown in the figure.
When the high pressured oil is supplied to the

opposite port of motor, the rotating direction
reverses and the sun gear (A) rotates in the
opposite direction.
The rotation of sun gear (A) is transmitted to

the reduction gear.
The torque and rotation speed generated by

hydraulic motor depend on motor displacement
(motor displacement for one rotation).
And the motor displacement for one rotation
corresponds to cam angle ø.
1-2. Speed change (Transmission) function

The torque and rotation speed generated by
hydraulic motor depend on motor displacement
(motor displacement for one rotation).
And the motor displacement for one rotation
corresponds to cam angle ø.
The larger the cam angle ø is, the larger the

torque becomes.
The smaller the cam angle ø is, the smaller the

torque becomes.
The travel unit is equipped with 2-speed change

piston, and when high pressure is supplied to
this piston, the 2-speed change piston pushes
cam and makes the cam angle smaller. That is,
the motor is changed from low speed mode to
high speed mode by the action that the
2-speed change piston pushes cam.
24-82
1-3. Function of parking brake

The travel unit is equipped with parking brake.
When high pressured oil is not supplied to
motor and the motor is not rotated, the parking
brake actuates automatically. And when high
pressured oil is supplied to motor and the
motor is rotated, the parking brake is
automatically released.
The parking brake is released immediately

after high pressured oil is supplied to motor and
the motor is starts rotating. When high
pressured oil is stopped supplying to the
parking brake, the hydraulic oil motor stops
rotating and the brake piston is gradually
pushed leftward by spring force and
consequently the parking brake gradually
actuates, too.
The parking brake is gradually operated to

prevent damaging friction plate and separator
plate.
24
24-83
2. Brake valve part
The brake valve has the following 3 functions.

2-1. Functions of counterbalance valve
Function to prevent the shock due to travel stop, and the unintended overrun and cavitation on
downhill
Function to supply high pressured oil to parking brake release section immediately before the travel
unit starts rotating
2-2. Functions of shockless crossover relief valve

Function to reduce the shock during travel reduction or in stop operation
Function to prevent motor from overloading
Function to compensate the shortage of oil supply during speed reduction or in stop operation
Relief valve is of "Shockless type" which is available for shock reduction.
2-3. Auto 2-speed change function

The speed of motor is switched in the following 2 modes.
1) Constant low speed mode - Usually at low speed
2) Auto 2-speed change mode
a. In light travel load, high speed mode
b. In heavy travel load, low speed mode
24-84
2-1. Function of counterbalance valve

Traveling on flat ground
When high pressured oil is not supplied to
brake valve, counterbalance spool is set to the
center position by 2 springs installed on both
sides. In this condition, the oil passage from
motor is blocked.
After high pressured oil is led to port on the

right side of brake valve, counterbalance spool
is shifted to the left position by the pressure
at the right end. In this condition, the oil
passage from motor closes at the left of
counterbalance spool and accordingly oil flows
and the motor starts rotating. When the supply
oil rate to right port is reduced by the speed
reduction of the machine and the stop
operation, the pressure lowers at the right end
of counterbalance spool. As a result, the
counterbalance spool is moved rightward by
the force of spring on the spool left side.
Then, the opening of counterbalance spool
becomes narrow and finally when high
pressure supply to brake valve stops, the
opening completely closes. This action of
"completely closing" raises the pressure (back
pressure) in the motor outlet side.
Traveling on downhill
When counterbalance is not provided,

When the machine travels on downhill, the
speed is up unintentionally due to the specific
gravity. It is impossible to avoid this
"overrunning" by controlling the supply oil
quantity to motor. And then the high pressure
pump can not maintain the oil supply rate
resulting in cavitation inside of motor.
Function of counterbalance valve and mechanism

In traveling on downhill, the pressure to right port lowers due to the shortage of supply oil quantity to
motor. Accordingly the pressure on the right side of counterbalance valve also drops and the
counterbalance spool moves from the left side to the right. Then the opening of counterbalance spool 24
becomes narrow resulting in the pressure rise on the motor outlet. This back pressure prevents
overrunning and cavitation of motor.
Hydraulic pressure supply for parking brake release

To start rotating travel unit, when the oil delivered by pump is supplied to right port of brake valve,
counterbalance valve spool moves leftward and opens the oil passage for parking brake release.
The oil passage for parking brake release is closed with the travel unit stopped.
For details of parking brake functions, see Item "1-3. Function of parking brake".
24-85
2-2. Functions of crossover relief valve

The travel unit is equipped with 2 shockless
crossover relief valves. The purpose is as
shown below.
Relief valve is useful to ease the shock in
slow-down and stop operation.
Function to prevent overloading to motor
Function to make up the shortage of oil
supply during speed reduction or in stop
operation
Relief valve is of "Shockless type" which is
available for shock reduction.
When crossover relief valve is not provided,
(Two cases are taken as example.)
1)
In slow-down or stop operation, the pressure in
motor (back pressure) is raised with the function
of counterbalance valve. (See Item 2-1.) When
the machine is abruptly stopped, if crossover
relief valve is not provided, this back pressure
is abruptly produced and then operator feels
as a certain shock.
In the worst case, it might damage the machine.
2)
In travel start operation of the machine, high
pressured oil is supplied to motor. When being
abruptly started traveling, if crossover relief
valve is not provided, the pressure in motor is
abruptly raised causing shock.
The travel unit is equipped with crossover
relief valves to ease the harmful pressure
shock, to improve bad feeling of operator and
to protect machine from possible damage.
Function of shockless crossover relief valve and mechanism

See the figure in Item "2-1. Function of counterbalance valve" and Figure on the upper side in this
page.
The explanation for relief valve (right) is given here.
The relief valve is set to the above condition (1) first.
Case of Fig. (2).
The abrupt pressure rise on the motor outlet side in slow-down and stop operation pushes down
shockless piston in relief valve with the shock due to high pressured oil, and simultaneously poppet
moves and escapes high pressure.
In moving shockless piston downward, the pressure on the poppet back face is not very high
because oil flow used to move shockless piston exists, and as a result the relief pressure is lowered.
Case of Fig. (3).
And then, when shockless piston was pushed down to the stroke end completely, the relief pressure is
raised fully to the set pressure. Because oil flow used to move shockless piston is no longer exist and
the back pressure of poppet is high. After stopping motor, when the motor is rotated again the
shockless piston is reset and the shockless piston is pushed up by high pressure at motor inlet.
24-86
Oil filling
In relief operation, the relief valve has function to deliver the relieved oil from the motor outlet to inlet.
This function prevents the inside of motor from being in excessively negative pressure.
2-3. Auto 2-speed change function

The speed of motor is switched in the
following 2 modes.
1) Constant low speed mode - Usually at low
speed
2) Auto 2-speed change mode
a. In light travel load, high speed mode
b. In heavy travel load, low speed mode
The above functions are performed by the
following two parts.
Spool (For mode change and auto speed
change)
Auto speed change mode (When pressure PP
is supplied)
In case of negative pressure < In specified
pressure, high speed mode
In case of negative pressure > In specified
pressure, low speed mode
Constant low speed mode (When pressure PP
is not supplied)
High pressure select valve
The higher pressure at port is selected always,
and the high pressure is supplied to 2-speed
change spool regardless of motor rotation
direction.
Function
See Item 1).
When pilot pressure PP is not pressurized, the
spool is rested on the upper side by spring
force, and the mode is switched in constant low
speed mode.
See Item 2).
When being in low load pressure, the pilot
pressure exerts on the spool upper side, and
consequently the spool moves downward and
the mode is switched in high speed mode.
When load pressure rises, the load pressure
exerts on the spool differential area and
gradually pushes back the spool upward and 24
the mode is switched form high speed to low
speed at the specified load pressure.For
variation of cam angle, see Item "1. Hydraulic
motor part 1-2. Speed change (Transmission)
function".
24-87
3. Reduction gear
The reduction unit has the following two functions.
3-1. Slow-down function

The reduction unit is transmitted the rotation from hydraulic motor and changes the rotation as shown
below.
Rotation speed is reduced
Torque is increased
3-2. Final power output function

The final rotation power output (torque) is transmitted to the machine sprocket.
24-88
Planetary reduction gear

The rotation of hydraulic motor shaft is
transmitted to reduction unit.
The function is as follows.
The construction of general planetary reduction
gear is shown in right figure.
The reduction unit is mainly equipped with the
following 4 parts.
Name / Gear tooth number

Sun gear: Zs
Planetary gea: Zp
Carrier: --
Ring gear: Zr
(1) Planetary type

First, since the ring gear is fixed, the case where the rotation is transmitted by sun gear is
explained here. This is called "planetary type". When sun gear rotates in clockwise, planetary
gear rotates around the sun gear. The carrier is correspondingly rotated by the revolution.
And the rotation in counterclockwise is transmitted from carrier by rotating sun gear in clockwise.
The rotation speed of carrier (output) differs from rotation speed of sun gear (input) and the ratio
(input)/(output) is called "reduction gear ratio (i)", and the equation is as follows.
Reduction gear ratio (i) = (Input) / (Output) = Zr / Zs + 1
(2) Star type
And the case where carrier is fixed, the case where the rotation is transmitted by ring gear is
explained here. This is called "star type". When sun gear rotates in clockwise, planetary gear
rotates at the position and then ring gear rotates in counterclockwise.
And the rotation in counterclockwise is delivered from ring gear by rotating sun gear in clockwise.
The rotation speed of ring gear (output) differs from rotation speed of sun gear (input) and the
reduction gear ratio is as follows.
Reduction gear ratio (i) = (Input) / (Output) = Zr / Z
(3) In case of travel unit,
Travel unit is equipped with two-stage planetary reduction gear mechanism and both the planetary
type and the star type exist together. The input is transmitted to sun gear on the 1st stage and
the output is transmitted from ring gear. The ring gear is shared by 1st stage and 2nd stage.
Reduction gear ratio (i) = (Input)/(Output)
= (Zr / Zs1 + 1) X (Zr / Zs2 + 1) - 1
Where,
Zs1 : Tooth number of sun gear on 1st stage
Zs2 : Tooth number of sun gear on 2nd stage
Zr : Tooth number of ring gear
Final output 24
The ring gear is equipped with flange used to install sprocket for travel. The final rotation and torque
are taken out of the flange of ring gear.
24-89
24.1.7 SWIVEL JOINT

24.1.7.1 GENERAL VIEW
General view of swivel joint
ITEM SPECIFICATION
PARTS No. YT55V00009F1
Working pressure
29.4 MPa (4263 psi)
High pressure port Max. impact pressure (pressure
44.1 MPa (6395 psi)
A, B, C, D proof)
66 L/min (17.4 gal/min)
Rated flow
Low pressure port Working pressure 0.5 MPa (73 psi)
E Rated flow 20 L/min (5.3 gal/min)
Working pressure
29.4 MPa (4263 psi)
High pressure port Max. impact pressure (pressure
44.1 MPa (6395 psi)
F, G proof)
49 L/min (12.9 gal/min)
Rated flow
Low pressure port Working pressure 3.5 MPa (508 psi)
H Rated flow 20 L/min (5.3 gal/min)
Revolution 15 min-1
A, B, C, D PF1/2
F, G PF3/8
Port size
E (stem) PF3/8
H PF1/4
Total length : L 397 mm (15.63")
Weight 28 kg (62 lbs)
24-90
Construction

1 BODY 1 8 O-RING 2
2 STEM 1 9 SOCKET BOLT (M8X20) 3
3 THRUST PLATE 1 10 SOCKET BOLT (M8X30) 1
4 COVER 1 11 PLUG : PT1/8 3
5 SEAL 5 12 PLUG : PF1/4 2
6 SEAL 1 13 PLUG : PT3/8 1
7 O-RING (G95 1A) 1 16 O-RING 2
24.1.7.4 OPERATION
The swivel joint consists mainly of mutually rotating body (1) and stem (2), thrust plate (3) that
prevents them from coming off, cover (4) that plugs up one part of body (1), seals (5), (6) that
partitioning circuits, and O rings (7), (8) that prevents oil from leaking out.
Four ports for the travel main circuits are provided on body (1) and stem (2). Further, four oil passing
grooves are arranged in the inner surface of body (1), with seal (5) fixed above and below the
circumferential groove. 24
The body (1) and the stem (2) rotate mutually. The oil flowing in from body (1) or stem (2) keeps on
flowing to stem (2) or body (1) past the circumferential groove between body (1) and stem (2) ; the oil
flow is never shut off because of rotation. Further, an oil groove for lubrication that connects with the
drain port is provided, in order to prevent the body (1) from binding with the stem (2). Such
construction of the swivel joint makes it possible to connect circuits between the swing body and the
lower travel body at all times.
24-91
24.1.8 CYLINDER
(1) General View
General view of cylinder
(2) Specifications
Unit: mm(ft-in)
Center
Part No. of Cylinder bore / distance of pins Dry weight
Use Stroke Cushion
cylinder assy Rod Dia. Full extend B / kg (lbs)
Full retract A
110 / 70 916 2,291 / 1,375 With cushion 93
Boom YT01V00034F1
(4.33"/2.76") (30.1") (7'6" / 4'6") on rod side (205)
95 / 65 833 2,134 / 1,321 With cushion 70
Arm YT01V00031F1
(3.74"/2.56) (32.8") (7'08" / 4'4") on both sides (154)
80 / 55 735 1,855 / 1,120 50
Bucket YT01V00032F1 Without
(3.15"/2.16") (28.9") (6'1" / 3'8") (110)
120 / 70 125 830 / 705 51
Dozer YT01V00035F1 Without
(4.72"/2.76") (4.92") (32.7" / 27.8") (112)
24-92
24.1.8.2 CONSTRUCTION AND FUNCTION

24.1.8.2.1 Construction
(1) Boom cylinder
Construction of boom cylinder

1 CYLINDER TUBE ASSY 1 11 O-RING 1 21 SET SCREW 1
2 PISTON ROD ASSY 1 12 HOLDER 1 22 STEEL BALL 1
3 ROD COVER 1 13 CUSHION SEAL 2 23 PIN BUSHING 2
4 BUSHING 1 14 COLLAR 1 24 WIPER RING 2
5 SNAP RING 1 15 BACKUP RING 1 25 PIN BUSHING 2
6 BUFFER RING 1 16 CUSHION BEARING 1 26 WIPER RING 2
7 U-RING 1 17 PISTON 1
8 WIPER RING 1 18 SEAL RING ASSY 1
9 O-RING 2 19 SLIDE RING 2
10 BACKUP RING 1 20 NUT 1
24
24-93
(2) Arm cylinder
Construction of arm cylinder

1 CYLINDER TUBE ASSY 1 11 O-RING 1 21 CUSHION BEARING 1
2 PISTON ROD ASSY 1 12 HOLDER 1 22 CUSHION SEAL 1
3 ROD COVER 1 13 BACKUP RING 1 23 STOPPER 2
4 BUSHING 1 14 CUSHION BEARING 1 24 SNAP RING 1
5 SNAP RING 1 15 CUSHION SEAL 1 25 PIN BUSHING 4
6 BUFFER RING 1 16 PISTON 1 26 WIPER RING 4
7 U-RING 1 17 SEAL RING ASSY 1
8 WIPER RING 1 18 SLIDE RING 2
9 O-RING 1 19 SET SCREW 1
10 BACKUP RING 2 20 STEEL BALL 1
24-94
(3) Bucket cylinder
Construction of bucket cylinder

1 CYLINDER TUBE ASSY 1 12 PISTON 1 23 O-RING 4
2 PISTON ROD ASSY 1 13 SEAL RING ASSY 1 24 NIPPLE 1
3 ROD COVER 1 14 SLIDE RING 2 25 O-RING 1
4 BUSHING 1 15 SET SCREW 1 26 BAND ASSY 1
5 SNAP RING 1 16 STEEL BALL 1 27 BAND 2
6 BUFFER RING 1 17 PIN BUSHING 1 28 BOLT 4
7 U-RING 1 18 WIPER RING 4 29 WASHER 4
8 WIPER RING 1 19 PIN BUSHING 1 30 PIPE HOLDER 2 24
9 O-RING 1 20 PIPE ASSY 1 31 BOLT 2
10 BACKUP RING 1 21 PIPE ASSY 1 32 SPRING WASHER 2
11 O-RING 1 22 PLUG 2
24-95
(4) Dozer cylinder
Construction of dozer cylinder

1 CYLINDER TUBE ASSY 1 8 BUSHING 1 15 O-RING 1
2 PISTON ROD ASSY 1 9 SNAP RING 1 16 PIN BUSHING 2
3 PISTON 1 10 U-RING 1 17 WIPER RING 4
4 NUT 1 11 BACKUP RING 1 18 FITTING 2
5 ROD COVER 1 12 WIPER RING 1 19 BUFFER RING 1
6 SLIDE RING 2 13 O-RING 1
7 SEAL RING ASSY 1 14 BACKUP RING 1
24-96
HYDRAULIC CYLINDER CONSTRUCTION (See construction of arm cylinder Fig.)

The hydraulic cylinder is composed of three sections, cylinder tube assy (1), piston rod assy to
transmit the motion of piston (16) stroke in the tube, a rod cover (3) which serves as the cover and
guide. Also, the cylinder tube assy and piston rod assy (2) have piston mounting section (clevis) which
are used to connect the other device. And, in addition to these principal parts, seal ring assy (17),
slide ring (18) and piston rod assy (2), buffer ring (6), U-RING (7), and wiper ring (8) between piston
rod assy (2) and rod cover (3), and O ring and backup ring between cylinder tube assy (1) and rod
cover (3).
24.1.8.2.2 OPERATION
By feeding pressure oil through oil inlet and outlet on cylinder alternately, the oil pressure exerts on
the piston, and piston rod assy (2) starts moving the telescopic motion (stroke).
(1) Operation of cylinder with cushion

The hydraulic cylinder contains a shock absorber to shock generated when the moving piston rod
assy (2) strikes rod cover (3) without speed reduction.
(Cushion on rod side)

When pressurizing the rod cover side, the oil
in (A) chamber returns to the tank in constant
speed through passage (B) in the midway of
stroke. (See the right Fig.) Cushion on the rod side
As the end of the stroke approaches, the

cylinder bearing enters into passage (B), and
the passage (B) is throttle reducing oil
quantity. As a result, the speed of piston rod
is also lowered. (See the right Fig.)
Cushion on the rod side
(Cushion on head side)

Like the cushion on the rod side, the piston
end of the piston rod enters into the cushion
bearing, and passage (B) is throttled. As a
result, as the return oil level for (A) chamber
Cushion on the head side
lowers, the speed of piston rod lowers,
obtaining the effect of cushion. (See the right
Fig.)
Cushion on the head side
24
24-97
24-98
24.2 ELECTRICAL EQUIPMENT
24.2.1 ELECTRICAL EQUIPMENT LIST
Group Code Part Name Part No.

C - 1 MECHATRO CONTROLLER YN22E00425F1
C - 2 GAUGE CLUSTER YN59S00021F3
(C) Controller
C - 4 AIR CONDITIONER CONTROLLER YN20M01468P4
C - 10 EGR CUT CONTROLLER VI898030-5740
D - 1 DIODE YN02D01001P1
D - 2 DIODE
D - 3 DIODE
D - 5 DIODE Fuse & relay box accesory parts
D - 6 DIODE
D - 9 DIODE
D - 10 DIODE
D - 12 DIODE
D - 13 DIODE
(D) DIODE
D - 14 DIODE
D - 16 DIODE
D - 17 DIODE
D - 21 DIODE Fuse & relay box accesory parts
D - 22 DIODE
D - 23 DIODE
D - 24 DIODE
E - 1 FUSE & RELAY BOX YY24E00008F2
E - 2 ALTERNATOR VI8971822892
(E) ELECTRIC E - 3 HOUR METER LQ58S00002P1

FITTINGS E - 6 HORN LOW LC53S00001D2
E - 7 TUNER AM / FM YN54S00046P2
E - 10 RECEIVER DRYER YN54S00041P1
24
24-99
Group Code Part Name

E - 11 AIR COMPRESSOR YX91V00001F1
E - 12 BATTERY PW72S00004P1
E - 13 TRAVEL ALARM YN53S00004F1
(E) ELECTRIC
E - 22 DC-DC CONVERTER YT77S00001P1
FITTINGS
E - 23 12V SOCKET YN81S01002P1
E - 35 GLOW VI8970476041
E - 65 24V SOCKET LQ81S01001P1
L - 1 BOOM WORKING LIGHT LEFT YN80S00012F1
L - 3 SWING FLASHER (LH) YY80S00001F1
(L) LIGHT L - 4 SWING FLASHER (RH)
L - 7 CAB WORKING LIGHT FRONT 1 YT80S00002F1
L - 8 CAB WORKING LIGHT FRONT 2
M - 1 STARTER MOTOR VI8971374781
M - 2 GOVERNOR MOTOR YN20S00002F1
(M) MOTOR M - 3 WIPER MOTOR LQ53C00003S001
M - 4 WASHER MOTOR YT54C00003F1
M - 12 FUEL PUMP VI897041-5212
R - 1 BATTERY RELAY YN24S00008F1
R - 3 GLOW RELAY VI8980305730
R - 4 SAFETY RELAY VI182553-0391
R - 5 HORN RELAY YN24S00010P1
R - 6 WORKING LIGHT RELAY
R - 8 TRAVEL ALARM RELAY
R - 15 (NIBBLER OPEN RELAY)
R - 16 (NIBBLER CLOSE RELAY)
R - 23 AUTO IDLE STOP RELAY 1
R - 24 AUTO IDLE STOP RELAY 2
(R) RELAY
R - 26 LEVER LOCK RELAY
R - 28 ALTERNATOR RELAY
R - 29 WIPER MOTOR RELAY
R - 29 WIPER MOTOR RELAY YN24S00012P2
R - 30 WIPER MOTOR RELAY
R - 31 PREVENT SPARK RELAY
R - 32 WINDOW WASHER MOTOR RELAY
R - 42 EXTRA (B) RELAY YN24S00010P1
R - 43 EXTRA (A) RELAY
R - 49 EGR CUT RELAY VI5825500300
24-100
Group Code Part Name Part No.

SE - 1 PRESS. SENSOR : BUCKET DIGGING YX52S00013P1
SE - 2 PRESS. SENSOR : BUCKET DUMP
SE - 3 PRESS. SENSOR : BOOM UP
SE - 4 PRESS. SENSOR : BOOM DOWN
SE - 7 PRESS. SENSOR : ARM IN
SE - 8 PRESS. SENSOR : ARM OUT
SE - 9 PRESS. SENSOR : TRAVEL RIGHT
SE - 10 PRESS. SENSOR : TRAVEL LEFT
ENGINE REVOLUTION SENSOR VI1815105130
SE - 13
ENGINE REVOLUTION SENSOR (FOR LOADING MECHATRO) VI8941268220
(SE) SENSOR
SE - 14 ENGINE COOLANT THERMO SENSOR VL8970633010
SE - 15 FUEL SENSOR YN52S00045F1
SE - 16 ACCEL POTENTIO, METER LQ52S00025P1
SE - 24 (PRESS. SENSOR : BOOM HEAD) YN52S00048P1
SE - 25 (PRESS. SENSOR : BOOM ROD)
SE - 40 PRESS. SENSOR : SWING RIGHT YX52S00013P1
SE - 41 PRESS. SENSOR : SWING LEFT
SE - 47 PRESS. SENSOR : DOZER DOWN
SE - 48 PRESS. SENSOR : DOZER UP
SE - 53 PRESS. SENSOR : BOOM SWING
SV - 1 SWING PARKING BRAKE SOL. YN35V00051F1
(YT35V00027F1)
SV - 3 TWO-SPEED SELECT SOL. YN35V00050F1
SOLENOID VALVE ASSY
(SV) SOLENOID SV - 4 LEVER LOCK SOL.
SV - 15 ENGINE STOP SOL. VI897209-1152
SV - 37 EGR CUT SOL. VI8980305970
SW - 1 KEY SWITCH YN50S00026F1
SW - 4 SWING PARKING BRAKE SWITCH YN50S00047P1
SW - 5 HORN SWITCH RIGHT YN50E00017P1
SW - 6 ENGINE WATER TEMP. SWITCH VI8971256001
SW - 7 ENGINE OIL PRESS. SWITCH VI1824100082
SW - 8 AIR FILTER RESTRICTION SWITCH A/C accesory
SW - 10 HORN SWITCH LEFT YN50E00017P1
(SW) SWITCH
SW - 11 LEVER LOCK SWITCH YN50S00055F1
SW - 13 TRAVEL ALARM SWITCH YN50S00040DF
SW - 15 (CONFLUX / SINGLE SELECT SWITCH) YN50S00040DD
SW - 17 (ROOF WIPER SWITCH) YN50S00040D9
SW - 19 WIPER INTERLOCK SWITCH YT50S00004P1 24
SW - 26 CAB WORK LIGHT SWITCH YN50S00040D4
SW - 55 BOOM-DECK WORKING LIGHT SWITCH YN50S00040D1
24-101
24.2.2 SPECIFICATIONS ELECTRICAL EQUIPMENT
24-102
24
24-103
24-104
24
24-105
24-106
24
24-107
24-108
24
24-109
24-110
24
24-111
24-112
24
24-113
24-114
24
24-115
24-116
24
24-117
24-118
24
24-119
24-120
［25. AIR-CONDITIONER SYSTEM］
25
25. AIR-CONDITIONER SYSTEM

TABLE OF CONTENTS
25.1 BASIC SYSTEM OF AIR CONDITIONER (HVAC AIR CONDITIONER) ………………………………25-3

25.1.1 AIR CYCLE …………………………………………………………………………………………………25-3
25.1.2 AUTO AIR CONDITIONER SYSTEM OUTLINE ……………………………………………………25-4
25.2 COMPONENT AND CONSTRUCTION ………………………………………………………………………25-5
25.2.1 COMPONENT ………………………………………………………………………………………………25-5
25.2.2 CONSTRUCTION …………………………………………………………………………………………25-6
25.3 PIPING ……………………………………………………………………………………………………………25-8
25.3.1 AIR CONDITIONER ………………………………………………………………………………………25-8
25.3.2 AIR DRYER ASSY ………………………………………………………………………………………25-13
25.4 FUNCTION ………………………………………………………………………………………………………25-14
25.4.1 MECHANISM OF COOLING CIRCUIT …………………………………………………………………25-14
25.4.2 COOLING CIRCUIT ………………………………………………………………………………………25-16
25.4.3 COMPONENT PARTS ……………………………………………………………………………………25-17
25.5 DISASSEMBLY AND ASSEMBLY……………………………………………………………………………25-21
25.5.1 PRECAUTIONS TO BE EXERCISED IN OPERATION ……………………………………………25-21
25.5.2 DISASSEMBLY AND ASSEMBLY OF UNIT …………………………………………………………25-23
25.6 CHARGING REFRIGERANT …………………………………………………………………………………25-27
25.6.1 PRECAUTIONS TO BE EXERCISED IN OPERATION ……………………………………………25-27
25.6.2 OPERATING PROCEDURE ……………………………………………………………………………25-29
25.6.3 CHARGING PROCEDURE ………………………………………………………………………………25-30
25.7 ELECTRIC CIRCUIT ……………………………………………………………………………………………25-36
25.7.1 WIRING DIAGRAM AND CONNECTORS ……………………………………………………………25-36
25.7.2 STRUCTURE AND OPERATION OF EACH FUNCTIONAL PARTS AND THE INSPECTION
…………………………………………………………………………………………………………………………25-38
25.8 TROUBLESHOOTING …………………………………………………………………………………………25-41
25.9 SELF DIAGNOSIS FUNCTION ON DISPLAY OF PANEL ………………………………………………25-48
25.9.1 POSITION OF INDICATION FOR FAILURE …………………………………………………………25-48
25.9.2 EXPLANATION OF INDICATION FOR FAILURE ……………………………………………………25-48
25.9.3 EXPLANATION OF MONITOR MODE …………………………………………………………………25-50
25-1

S5LF2514E01
First Edition October, 2010 SK80MSR-2 : LF06-04547~
(AUS)
SK70SR-2 : YT06-18444~
(AUS)
25-2
25.1 BASIC SYSTEM OF AIR CONDITIONER (HVAC AIR

CONDITIONER)
25
Air-conditioner is the unit which places evaporator and heater core parallel, and unifies a blower fan
and an inside / outside air switching unit. And this unit changes hot air to cool air.
25.1.1 AIR CYCLE

・ Heater
Inside air or outside air is taken in through intake port and the air is passing through filter and
heat exchange is performed with hot air (heating) at the heater core of air-con unit, and then the
heated air blows off from grille through duct.
・ Cooler
Inside air or outside air is taken in through intake port and the air is passing through filter and
heat exchange is performed with cold air (dehumidifying and cooling) at the evaporator of air-con
unit, and then the cooled air blows off from grille through duct.
・ Heater system
The heater recycles (circulates) the cooling water in the engine, and the hot water delivered by
the engine flows in the heater core of air-con unit and then heat exchange is performed.
The intake air is heated and the heated air blows off from the grille provided on the inside of cab.
The blow off air temperature is controlled by the temperature control switch on the control panel,
and the operation is controlled by air mixing damper on the air-con unit.
25-3
25.1.2 AUTO AIR CONDITIONER SYSTEM OUTLINE
25-4
25.2 COMPONENT AND CONSTRUCTION
25
25.2.1 COMPONENT
Air-conditioner group
A/C ASSY: YT20M00023F1 (02)

No. Parts Q'ty No. Parts Q'ty No. Parts Q'ty
27 Air-conditioner assy 1 34 Condenser 1 35-9 S tube 1
27-1 Air-conditioner unit 1 35 Air dryer assy 1 35-10 L tube 1
27-2 Hose 2 35-1 Receiver dryer 1 35-11 D tube 1
27-3 Clamp 2 35-2 Bracket 1 35-12 L tube 1
27-4 Filter 1 35-5 S hose 1 39 Filter 1
30 Panel assy 1 35-6 D hose 1 40 Solar radiation sensor 1
32 Compressor 1 35-7 L hose 1
33 Pulley 1 35-8 L hose 1
25-5
25.2.2 CONSTRUCTION
(1) Air conditioner unit
Air conditioner unit
25-6
Air conditioner unit: YT20M00022F2 (01)

No. Parts Q'ty No. Parts Q'ty No. Parts Q'ty
1 Screw, tapping 19 19 Relay 2 62 Packing 1 25
2 Conditioner, air 1 20 Evaporator 1 63 O-ring 1
3 Motor, elec 2 21 Valve assy 1 77 Packing 1
6 Dumper 1 22 O-ring 1 78 Tube 1
7 Lever 1 23 O-ring 2 79 Tube 1
9 Dumper 1 24 Capscrew 2 82 Tube 1
10 Lever 1 26 Holder 1 83 Bracket 1
12 Lever 1 27 Core 1 84 Case 1
13 Dumper 1 28 Holder 1 85 Thermometer 1
14 Lever 1 31 Screw, tapping 6 93 Case 1
15 Lever 1 51 Plate 1 94 Thermometer 1
16 Rod 1 54 Capscrew 1 110 Conditioner, air 1
17 Rod 1 60 Packing 1 111 Blower assy 1
18 Rod 1 61 Packing 1 112 Resistor 1
(2) Receiver dryer
Receiver dryer
25-7
25.3 PIPING
25.3.1 AIR CONDITIONER
Air conditioner piping (1/4)
25-8
25
25-9
25-10
25
25-11
Air conditioner: YT20M00023F1 (02)

torque No. Parts Q'ty torque No. Parts Q'ty
1 Hose : L = 2100 2 30 Panel 1
3 Bracket 2 32 Compressor assy 1
4 V-belt 1 46.5 (34.3) 33 Pulley assy 1
3.92~4.9 (2.9~3.6) 5 Clip 4 34 Condenser 1
6 Sems bolt : M10X25 5 35 Air dryer assy 1
7 Sems bolt : M6X20 2 39 Filter 1
8 Sems bolt : M8X20 7 40 Solar radiation sensor 1
9 Capscrew : M8X100 4 41 Washer 4
10 Washer 4 42 Clip 6
12 Tube for heater : L = 1800 1 49 Clip 3
13 Tube for heater : L = 1700 1 50 Connector 2
14 Tube for D hose : L = 1450 1 51 Connector 1
15 Tube for S hose : L = 1500 1 52 Connector 1
16 Bracket 1 53 Clip 2
17 Tube for L hose : L = 1600 1 54 Grommet 1
19 Tube for L hose : L = 1400 1 55 Grommet 1
22 Capscrew 4 58 Insulation 1
24 Clip 1 59 Clip 2
25 Clip 15 23.5 (17.3) 60 Sems bolt: M8X16 4
27 Air conditioner assy 1
25-12
25.3.2 AIR DRYER ASSY
25
Air dryer assy: YT96V00004F1 (01)

1 Receiver dryer 1 7 L hose 1
2 Bracket 1 8 L hose 1
20~25 (14.8~18.4) 3 Capscrew 2 9 S tube 1
8~12 (5.9~8.9) 4 Capscrew 4 10 L tube 1
5 S hose 1 11 D tube 1
6 D hose 1 12 L tube 1
25-13
25.4 FUNCTION
25.4.1 MECHANISM OF COOLING CIRCUIT

(1) Mechanism of Cooling
In the cooling process, the refrigerant that
flows through the cooling circuit changes its
phases from liquid to gas and vice versa during
which process heat is transferred from the low
temperature part (compartment) to the high
temperature part (outside of the vehicle).
1. Kind of Refrigerant
Many kinds of refrigerants that change in that
way are available, but the following equirements
are needed for use in such applications:
・ Latent heat of vaporization (heat of vaporization) is large.

・ It is easy to liquefy (condense). (It dose not require very high pressure for condensation.)
・ It is easy to gasify (evaporate). (It evaporates sufficiently at not too low pressure, i.e. cools down
an object.)
・ It has small specific heat. (Since the refrigerant itself is cooled by the expansion valve, the loss
resulting from it must be held down to a minimum.)
・ It has a high critical temperature and a low solidification point.
・ It is stable chemically and does not corrode and permeate into the circuit parts.
・ It is free from toxicity, objectionable odor, flammability and explosiveness and excels in thermal
conductivity and electric insulation.
・ It has small specific volume.
・ It is easy to find out leakage.
Out of refrigerants meeting the above-mentioned requirements, ones having characteristics that
suit the intended cooling unit are chosen and used. If a refrigerant other that those designated is
used, sufficient refrigeration will not be performed or the equipment in which the refrigerant is used
may be broken. Therefore, always use a designated refrigerant for the cooling unit.
Table shows the principal characteristics of the R134a refrigerant that is used in this machine.
25-14
(2) Characteristics of Refrigerant (Right Fig.)

In general, the fluid (general term of gas and
liquid) has the following qualities:
25
1.
As a gas under certain pressure is cooled
down, it begins to condensate at a certain
temperature to take a liquid state. The
temperature at which condensation begins is
unique to each substance (fluid) at a given
pressure. The temperature determined by a
given pressure is called saturation temperature.
Pressure-temperature characteristics of R134a
2.
Inversely to 1) above, the pressure at which a gas condenses for a temperature is determined. This
pressure is called saturation pressure.
above Fig. illustrates the relationships between the saturation temperature and the saturation pressure
in the case of refrigerant R134a used in the air-conditioner. At the temperature and the pressure on
the lower righthand side of the curve in above Fig. the refrigerant take a gaseous state, while at the
temperature and the pressure on the upper lefthand side of the curve, the refrigerant takes a liquid
state.
Let us think of a case where an air-conditioner is operated in the midst of summer. As the refrigerant
evaporates, it absorbs evaporation heat from the air of the compartment. In order to cool the inside of
the compartment down to 25C degrees (77F degrees), the refrigerant must transform (evaporate) from
a liquid to a gaseous state at a lower temperature. It can be seen from above Fig. that R134a under
a pressure above the atmospheric pressure is capable of cooling the inside of the compartment
sufficiently. (If a refrigerant that requires a pressure below the atmospheric pressure to cool it to a
required temperature is used, air is mixed into the circuits, thereby deteriorating the performance of the
cooling unit.) In the process in which gaseous refrigerant is brought back to a liquid state, the
refrigerant is cooled and condensed by the outer air exceeding 35C degrees (95F degrees).
Accordingly the refrigerant is capable of condensing at a pressure exceeding 1 MPa (145psi), as seen
from above Fig.
25-15
25.4.2 COOLING CIRCUIT

Right Fig. illustrates the cooling circuit of the
car air-conditioner.
In this circuit diagram, the portion that cools the
air of the compartment is the evaporator. The
object air is cooled off by utilizing the fact that
the refrigerant takes heat off the surrounding
area as evaporation heat as it evaporates in
the cooling circuit. Since the part at which
vaporization of the refrigerant takes place is
the evaporator, cooled air is constantly delivered
to the circumference of the evaporator by the
blower fan. In the meantime, liquid refrigerant
(slightly wet vaporized refrigerant) is fed into the
evaporator, when "cooling" effect is attained.
For instance, in order to cool the air to 15C
degrees (59F degrees), the refrigerant can not
Construction of cooling circuit
absorb evaporation heat from the air unless it
evaporates at a temperature lower that 15C
degrees (59F degrees). For that purpose, it
can be seen from right Fig. that the pressure of
the refrigerant in the evaporator must be less
than 0.51 MPa (74psi).
Furthermore, the cooling effect deteriorates
unless the feed rate of the refrigerant is
controlled so that all of the refrigerant supplied
to the evaporator vaporizes and turns into dry
vapor.
Consequently, the cooling circuit is so
constructed that the evaporator can cool down
an object (air in this case) sufficiently (i.e. so
as to decrease the pressure in the evaporator)
and that an adequate amount of refrigerant
can be fed to the evaporator.
The feed rate of the refrigerant is controlled by
the expansion valve, but the pressure in the
evaporator is held low by the throttling action of
the expansion valve and the suction action of
the compressor. The compressor acts as a
pump that allows the refrigerant to circulate.
The compressive action of the compressor and
the heat exchange (heat radiation) action of
the condenser transform the refrigerant in a
dry vapor state back to a liquid state.
25-16
25.4.3 COMPONENT PARTS

(1) Evaporator (See right Fig.) 25
The evaporator is an important heat exchanger
that absorbs the heat of the compartment air
(object) by the utilization of the latent
vaporization heat of the low-temperature,
low-pressure liquid-state refrigerant. Therefore,
it is necessary that satisfactory heat transfer
between the object and the refrigerant take
place in the evaporator.
To that end, the evaporator is equipped with
fins on the air side in order to increase the
heat transfer area of the air side and thereby
perform excellent thermal transfer between the
refrigerant and the air.
The humidity in the air condenses as the air
cools down and adheres to the outside of the
evaporator as water drops. The cooling effect
deteriorates if the water drops freeze. Therefore,
how to discharge water is an important point.
The amount of refrigerant supplied to the
evaporator is controlled by the expansion valve
which is described in the following. In order to
attain proper control, it is necessary to reduce
the pressure drop of the refrigerant of the
evaporator. Accordingly, reducing the pressure
drop is one element that makes the evaporator
attain its full performances.
(2) Expansion Valve

In order for the evaporator to fulfill its performances, a proper amount of low-pressure low-temperature
liquid refrigerant must be fed to the evaporator.
If the feed rate is too low, the refrigerant completes vaporization early in the evaporator which results
in deterioration of the cooling effect. If the feed rate is too high, unvaporized liquid refrigerant returns
to the compressor (liquid back). This not only deteriorates the cooling effect, but also damages the
compressor valves.
The expansion valve feeds the flowing high-pressure high-temperature liquid refrigerant to the
evaporator as low-pressure low-temperature liquid refrigerant (damp vapor of low dryness). The
expansion valve controls the feed rate of the refrigerant at the same time.
25-17
Right Fig. shows how the block type

expansion valve is constructed. The temperature
sensing part is provided in the shaft of the
expansion valve to directly detect the
refrigerant temperature at the outlet of the
evaporator.
The diaphragm contains R134a in saturated
state. The pressure in the diaphragm changes
according to the temperature detected by the
sensor. The change in the pressure causes
the force acting upon the diaphragm to vary
accordingly.
The high-pressure high-temperature liquid
refrigerant that is fed from the receiver side
reduces the pressure abruptly as it passes
through the valve (throttling action). On that Block type expansion valve
occasion, part of the refrigerant evaporates by
the very heat of the refrigerant and cooled off.
The result is that low-pressure low-temperature
damp refrigerant vapor is fed to the evaporator.
The opening of the valve is determined by the
equilibrium between the pressure (low) of the
evaporator side, the action of the adjust spring
and the pressing force of the diaphragm (the
temperature of the refrigerant at the outlet of
the evaporator to be sensed by the thermowell).
The feed rate is controlled automatically so
that under the pressure in the evaporator, the
refrigerant is properly overheated (3 to 8C
degrees ) and goes out of the evaporator. This
action is carried out by sensing the refrigerant
temperature at the outlet of the evaporator as
against the inlet pressure of the evaporator
and consequently controlling the feed rate of
the refrigerant.
This means that if the refrigerant pressure

drop in the evaporator is excessive, it is difficult
to control the overheating or the feed rate of
the refrigerant. For this reason, the smaller the
pressure drop of the evaporator, the better.
The expansion valve senses the pressure and
the temperature at the outlet of the evaporator
and controls the overheating of the refrigerant
Expansion valve outside view
and the refrigerant supply to the evaporator
more securely. The air-conditioner of this
machine adopts a block type expansion valve.
25-18
(3) Compressor (See right Fig.)

The compressor performs the following three
functions in the cooling circuit:
25
1) Suction action
2) Pumping action
3) Compressive action
1. The suction action, as combined with the throttling action, works to decrease the refrigerant
pressure in the evaporator. This permits the refrigerant to vaporize at low temperature in order to
perform cooling effect.
2. The pumping action serves to cause all the refrigerant to circulate in the cooling circuit. This
enables enables continuous cooling.
3. The compressive action, as combined with the action of the condenser which is mentioned
hereunder, transforms vaporized refrigerant back to a liquid state again.
The saturation temperature gets higher as the pressure increases. For instance, it becomes
possible to cool down the refrigerant by the use of an outer air of 35C degrees (77F degrees)
and liquefy it. The compressive action of the compressor works to turn low pressure vaporized
refrigerant to high pressure vapor refrigerant. The condenser then serves to cool down the
refrigerant. However, since the compressive action takes place only for a short period, the
refrigerant hardly exchanges heat with outer air. That is to say, it takes a near form of thermally
insulated compression, so that the refrigerant discharged by the compressor turns into
high-temperature high-pressure vapor and is delivered to the condenser.
(4) Condenser (See right Fig.)

This is a heat exchanger that cools the
vaporized refrigerant at high temperature and
high pressure by the use of outer air and
condenses the refrigerant. The direction in
which heat moves is from the refrigerant to air,
the opposite to the case of the evaporator. Fins
are equipped on the outer air side to improve
thermal transfer. If the refrigerant is not cooled
well by the condenser, the air in the
compartment can not be cooled sufficiently by
the evaporator. For that purpose, it is necessary
to secure ventilation required for the cooling of
the refrigerant. Condenser
25-19
(5) Receiver dryer (See right Fig.)

1. Receiver Tank
On the air-conditioner, the revolution of the
compressor varies greatly which causes
the proper flow of refrigerant in the cooling
circuit to vary. It is the receiver tank that
receives the variations. When the cooling
circuit does not need much refrigerant, the
receiver tank stores extra refrigerant
temporarily and supplies it when the cooling
circuit needs much refrigerant. The
receiver tank also stores an extra amount
of refrigerant to be used for filling balance
and supplement small amounts of leakage
of the refrigerant through penetration into
rubber hoses.
2. Dryer
If water is mixed in the cooling circuit, it
deteriorates the compressor valves and oil,
corrodes the metallic parts of the circuit or
clogs the circuit as the water freezes in the
expansion valve. It is desirable that the
amount of water mixed in the refrigerant
should be held below a concentration of
30ppm. The air-conditioner uses a
molecular sieve as desiccant suited for the
circuit, in order to absorb water content that
intrudes into the circuit when the dryer is
installed or when refrigerant is charged.
3. Sight Glass
This is a inspection window with which the
refrigerant level in the circuit is
determined, the only means of confirming
the inside of the circuit visually.
4. Filter
5. Pressure Switch
This machine employs pressure switches
of high/low pressure type.
The pressure switch protects the circuit by
cutting off the power supply to the
compressor when high pressure increases
abnormally high [more than 3.14MPa
(460psi) ].
The pressure switch also detects the
leakage of refrigerant by cutting the power
supply to the compressor when the
pressure of the circuit falls below 0.2MPa
(28psi).
25-20
25.5 DISASSEMBLY AND ASSEMBLY
25
25.5.1 PRECAUTIONS TO BE EXERCISED IN OPERATION
(1) Special Refrigerator Oil
This air-conditioner uses special refrigerator oil
SP20 for use with new refrigerant R134a. Oils
other than SP20 may not be used. Since
SP20 tends to absorb moisture and may
corrode paint and resin, the following points
must be noted:
1.
Do not keep open all pipe connections on a
new compressor and the component parts of
the installed refrigeration circuit
(Remove valves and caps at the pipe openings
of the compressor, just before connecting pipes.
If you have removed a pipe joint for repair,
put a cap to both ports immediately.)
2.
Use care so SP20 does not adhere to the
painted surface and resin parts. In case SP20
has adhered to such surfaces, wipe it off
immediately.
(2)
The receiver dryer is filled with desiccant to
absorb moisture in the circuit. Therefore,
remove the valve at the pipe port immediately
before connecting pipes.
(3)
Tightening Torque
1. Pipe Joints
When connecting pipe joints, coat the O-ring
with special oil (SP20) and fasten to the
tightening torque indicated in the table, using a
double spanner.
2. Screws and Bolts
Fasten to the tightening torque indicated in the
table
25-21
(4)
Amount of Oil for Compressor
The compressor SD7H (HD type) is filled with
135cc (8.2cuoin) of oil. If the oil volume is
small, seizure at high revolution and shortening
of service life will occur. If the oil volume is
large, the cooling ability will be deteriorated.
Once the air-conditioner is operated, part of
the oil is dispersed in the refrigeration circuit.
Therefore, when replacing the parts in right
Table, adjust the oil level to that of table.
(5)
Before performing operation, stop the engine
and turn off all power supplies to the equipment
related to the air-conditioner.
(6)
After the operation is over, confirm that all
faults have been repaired completely, by
operating the air-conditioner.
25-22
25.5.2 DISASSEMBLY AND ASSEMBLY OF UNIT

(1) Removing inner air filter
25
Slide the inner air filter leftward and remove it
from the unit.
(2) Removing selector box

Remove 6 plus screws, remove connector
connected to the mode actuator on mode
selector box, and separate the mode selector
box from the unit.
(3) Removing main harness

Pull out 3 harness clamps from the unit, and
disconnect all connected connectors and remove
harness on the body from the unit.
(4) Removing upper unit case

1.
Remove air MIX rod and air MIX rod sub from
air MIX lever.
2.
Remove 12 plus screws which are used to
install the upper and lower unit casings.
Pull out the upper unit casing upward giving
attention to the thermistor harness so as not
to be caught by the casing.
25-23
(5) Replacing blower controller

1.
Remove 2 plus screws and remove the blower
controller from the upper unit casing.
2.
Install new blower controller by the reverse
procedure of removal.
* Do not disassemble the blower controller.
(6) Removing heater core

1.
After draining the coolant, remove heater hose
from the heater core.
2.
Remove 1 plus screw, and remove pipe clamp
which is used to secure the heater core and
then remove the heater core from the lower unit
casing.
3.
Install it by the reverse procedure of removal.
(7) Replacing blower motor

1.
Disconnect connector which is connected to
the blower motor and remove the blower motor
from the lower unit casing.
* Do not remove the fan from the blower motor.
2.
Install it by the reverse procedure of removal.
(8) Replacing evaporator and expansion valve

1.
Take the evaporator with expansion valve off
from the lower casing.
2.
Remove evaporator sensor with sensor holder
from the removed evaporator.
3.
Insert the sensor holder into the new evaporator
at the position shown in right Fig. and install
the evaporator sensor again.
25-24
4.
Remove 2 socket bolts M5X40 with Allen
wrench (4mm) and remove the expansion
25
valve from the evaporator.
5.
Fit O-ring (NF O-ring 5/8 and 1/2 one each) to
new evaporator.
* When assembling again, fit O-ring paying
attention so as not to be caught with others.
(Socket bolt M5X40 (2 pcs.) Tightening torque
: 6.9Nom (5.1lbfoft)
* Do not apply undue force to pipe of
evaporator outlet. This undue stress causes
the leak of refrigerant from "A" part of
evaporator.
Moreover, when tube (78), (79) (see Structual
chart of air conditioner unit) connected with
expansion valve is disconnected from
expansion valve, similar careful work is
necessary.
(9) Replacing motor actuator

1. Replacing mode actuator
a.
Remove connector connected to the motor
actuator.
b.
Remove FACE rod and VENT rod which is
used to connect MA mode lever and mode cam
from the holder.
c.
Remove 3 plus screws and remove the motor
actuator with lever MA mode from the unit.
d.
Remove the lever MA mode from the removed
motor actuator, and install it on new motor
actuator by the reverse procedure of removal.
25-25
2. Replacing air mixing actuator

a.
Remove connector connected to the motor
actuator.
b.
Remove rod air MIX which is used to connect
the motor actuator and the lever MA air MIX.
c.
actuator with MA lever air MIX from the unit.
d.
Remove the MA lever air MIX from the
removed motor actuator, and install it on new
motor actuator by the reverse procedure of
removal.
3. Replacing inner and outer air switching

actuator
a.
Disconnect connector connected to the motor
actuator.
b.
Remove intake rod from MA intake lever.
c.
actuator with MA intake lever from the unit.
d.
Remove the MA intake lever from the removed
motor actuator, and install it on new motor
actuator by the reverse procedure of removal.
25-26
25.6 CHARGING REFRIGERANT
25
25.6.1 PRECAUTIONS TO BE EXERCISED IN OPERATION
(1) Always assign a person in charge of handling refrigerant.
Refrigerant charge operation involves dangers as it handles high pressure gas. Always assign a person
familiar with how work is done for handling refrigerant.
- Wear protective goggles. (You may lose your sight if the refrigerant gets in your eyes.)
- The refrigerant in liquid state is at very low temperature [approx. -26C degrees (-15F degrees)].
Therefore, handle it with care. (You may get a frostbite if the refrigerant is sprayed over your skin.)
(2) Storage and Transportation

1. Keep the service can (hereinafter called can) less than 40C degrees (104F degrees). Since high
pressure gas of R134a is filled in the can in a saturated liguefied state, the pressure in the can
increases sharply as temperature rises. The can may blast as the result.
It is for this reason why the can temperature must be kept below 40C degrees (104F degrees).
2. For storage, choose a cold dark place not exposed to direct sunlight.
3. If the can is placed near a fire source, it is subject to radiation heat and gets hot. This causes
the inside pressure to rise and may cause the can to blow out. Do not bring the can close to a
fire.
4. The inside of the closed compartment gets very hot as the radiation heat of the sunlight enters
the compartment. The areas of the compartment which are exposed to direct sunlight may rise to
a dangerous temperature level. Do not bring the can into the compartment. Also, the inside of
the trunk room may rise to a dangerous temperature level even in the summer time. Use sufficient
care, therefore, taking the above into account.
5. Note that if the can has scratches, dents and distortion, the strength of the can will deteriorate.
a. Do not drop or knock on the can.
b. When transporting, loading or unloading cans and packages containing cans, do not throw or
drop them.
6. Store cans beyond the reach of children.
(3) Charging
1. When warming the can in which refrigerant is charged, do not fail to open the service can valve
and the low pressure valve of the gauge manifold and warm the can in warm water of 40C
degrees (104F degrees or below (to an extent that you do not feel hot when you put your hand
in the water.) If the can is put in hot water or heated by a direct fire, the pressure of the can
may rise sharply, thereby blowing off the can.
2. When charging refrigerant while running the engine, do not open the high pressure valve (HI) of
the gauge manifold in any case.
25-27
(4) Others
Reuse of service cans is prohibited by law; never use them again. Do not allow foreign matter to
enter the air-conditioner circuit. Air, water and dust are detrimental to the refrigeration cycle. Install the
components of the air-conditioner correctly and speedily. Pay full attention to the entry of water and
dust.
- Be careful about overcharge of gas.

- Fasten pipes to the specified torque.
25-28
25.6.2 OPERATING PROCEDURE

(1)
25
Refrigerant charge into the air-conditioner consists mainly of "vacuum making operation", and "gas
charge operation".
1. The "vacuum making operation" consists of removing water in the air-conditioner circuit. If only a
little water remains in the circuit, the small holes of the expansion valve are frozen during
operation. This causes the circuit to clog up or rust, resulting in a variety of malfunctions.
Therefore, before filling refrigerant in the circuit, make vacuum and allow the water in the circuit
to boil and vaporize. Water in the circuit is thus eliminated.
2. The "gas charging operation" consists of filling refrigerant in the circuit after forming vacuum. Filling
gas not only depends upon the cooling performances of the air-conditioner, but also affects the
service life of the component parts of the circuit. Extreme overcharge will make the circuit pressure
extremely high and causes the cooling performance to deteriorate. On the contrary, undercharge
causes poor circulation of the lubricating oil of the compressor and causes seizure of the moving
parts of the compressor.
The gas filling operation involves handling of high pressure gas; filling gas according to incorrect
operation procedure is dangerous. Fill refrigerant correctly following the operation procedures and
cautions stated in this manual.
(2) Operation Chart
(3) Tools
25-29
25.6.3 CHARGING PROCEDURE

25.6.3.1 VACUUM MAKING OPERATION
(1) Connecting gauge manifold (See right Fig.)
1.
Close the high pressure valve (HI) and the low
pressure valve (LO) of the gauge manifold.
2.
Connect the charging hoses (red and blue)
with the service valves of the compressor.
Red hose :
High pressure side (HI) of the gauge manifold
--> high pressure side (DIS) of compressor
Blue hose :
Low pressure side (LO) of gauge manifold -->
low pressure side (SUC) of compressor
Do not mistake the high pressure hose for the low pressure hose in any circumstances when
connecting them. Put the hose in firmly till a clicking sound is heard.
3.
Connect the center valve of the gauge
manifold with the charging hose of the vacuum
pump.
Connecting gauge manifold
Some kinds of gauge manifolds are not equipped with an open/close valve in the center.
25-30
(2) Vacuum making (See right Fig.)

1.
Open the high pressure valve (HI) and the low
25
pressure valve (LO) of the gauge manifold.
2.
Turn on the switch of the vacuum pump and
make vacuum for more than 30 minutes.
3.
When vacuum making for a specified duration
is over (degree of vacuum : less than - 750
mmHg), close the high pressure valve and the
low pressure valve of the gauge manifold.
4.
Then turn off the vacuum pump.
Vacuum making operation
(3) Air-tightness Check

Close the high pressure valve and the low pressure valve of the gauge manifold, leave it as it is for
more than five minutes and make sure that the gauge indication does not return toward 0.
If the gauge indication goes toward 0, there is somewhere that is leaking. Retighten pipe joints,
make vacuum again and make sure of no leakage.
25-31
25.6.3.2 GAS CHARGING OPERATION

(1) Charging from high pressure side (See right Fig.)
1.
After making vacuum repeatedly, change the
charging hose (yellow) of the gauge manifold
from the vacuum pump to the service can.
2.
Air purge
Open the service can valve. (However, close
the high and low pressure valves of the gauge
manifold.) Then push the gas valve of the side
Gas charging operation
service port on the low pressure side of the
gauge manifold, using a screw driver, in order
to let out the air in the charging hose by the
pressure of the refrigerant. (See right Fig.)
(The operation ends when a hissing sound is
heard.)
3.
Open the high pressure valve of the gauge
manifold and charge in refrigerant. [Charge in
gaseous refrigerant to a gauge pressure of
0.1MPa (14psi).]
After charging, close the high pressure valve
of the gauge manifold and the service and
valve. (See right Fig.)
Gas charging operation (High pressure side)
Do not run the compressor during this work, (Otherwise the refrigerant flow in reverse direction which
causes the service can and the hoses to rupture. This is very dangerous.)
(2) Checking for gas leak

Check for gas leak in the cycle, using a gas leak detector (electric type). Retighten and correct leaking
points.
Always use the leak tester for R134a. (Do not use one for flon gas service as it provides poor
sensitivity.)
25-32
(3) Charging from low pressure side (See right Fig.)

1.
Make sure that the high-pressure and
25
low-pressure valves of the gauge manifold and
the service can valve are closed.
2.
Start the engine and run the revolution to
1500 to 100rpm and fully close the cab door
and the windows.
3.
Turn on the air-conditioner switch, set the fan
switch to Max and the temperature control
switch to cool Max.
4.
When charging gas, set the discharge pressure
Gas charging operation (Low pressure side)
of the compressor to 1.4 to 1.6 MPa (200 to
230psi).
5.
Open the low pressure valve of the gauge
manifold and the service can valve and fill in
refrigerant till air bubbles of the sight glass of
the receiver go away. (See Fig. "Gas charging
operation (Low pressure side)")
[Total amount of gas to be charged:
950g to 850g (2.09 to 1.87 lbs)]
6.
When refrigerant charge is over, close the low
pressure valve of the gauge manifold and the
service can valve. Receiver dryer
- Do not open the high pressure valve of the gauge manifold in any circumstances.
- Never place the service can upside down. (The compressor valve may be scored because the
refrigerant is sucked in a liquid state.)
25-33
(4) Criterion for checking the amount of refrigerant filled in
- If the air-conditioner is run with poor refrigerant R134a, it has adverse effect on the compressor.
- If the refrigerant is charged too much (overcharged), the cooling performance is deteriorated.
Moreover, the circuit pressure gets abnormally high: Always keep a proper level.
(5) Removing Gauge Manifold

When the refrigerant level has been checked, disconnect the charging hoses from the compressor in
the following manner:
1. Press the "L" shape metal fitting of the charging hose (blue) on the low pressure side against the
service valve of the compressor so the refrigerant does not leak out and loosen the nut. As soon
as the nut has been removed, disconnect the charging hose from the service valve.
2. Leave the high pressure side as it is till the high pressure gauge reading falls. [below 1MPa
(140psi)].
3. Disconnect the charge hose (red) on the high pressure side the same way as on the low pressure
side.
25-34
25
25-35
25.7 ELECTRIC CIRCUIT
25.7.1 WIRING DIAGRAM AND CONNECTORS
Electric diagram (1/2)
25-36
25
Electric diagram (2/2)
25-37
25.7.2 STRUCTURE AND OPERATION OF EACH FUNCTIONAL PARTS AND THE

INSPECTION
(1) Control panel and control unit
The control unit is integrated into control panel,
and processes the signal input by each
sensor, etc. and the signal input by each switch
through control panel with the function of the
built-in micro computer, and comprehensively
controls each actuator (Inner and outer air flow
select, air mix), fan motor and compressor on
the output side.
And the self-diagnosis performance is provided
to facilitate the trouble shooting.
(2) Blower controller (TKS-B215A1)

The power transistor shifts the fan motor into
variable speed with base current from the
control unit.
In normal operation
1.
Disconnect the connector of blower amplifier.
2.
Check continuity between terminals on the
blower amplifier side.
* The installing position is provided on the left

side of air-con unit.
25-38
(3) Relay
Four-electrode relay is used for the blower OFF relay and compressor relay.
25
1. Blower OFF relay
The blower OFF relay turns on after
receiving the signal from the control
amplifier.
When the blower OFF relay turns on, the
source voltage is supplied to the blower
motor and the blower motor starts running.
2. Compressor relay
The relay ON-OFF is tripped by the
control amplifier and electronic thermostat
control.
3. Relay inspecting items
a. Relay (24-4PE)
b. Coil resistance: 320 ohms
c. Specified voltage: DC20V to 30 V
d. Be careful about the coil side of relay
because this relay has polarity.
e. Inspection:
Inspect the continuity between 3 and 4
according to the conditions mentioned
below.
20 to 30 V applied between terminals 1-2:
Continued
20 to 30 V not applied between terminals
1-2: Not continued
(4) Air mix actuator

Air mix actuator is installed at the center of
air-con unit, and opens and closes air mix
damper through the link.
The air mix actuator contains potentiometer
which is switched by being coupled to the
shaft of actuator.
When the target air mix door position is
determined through the temperature control
switch, the control unit reads the level of
potentiometer of the actuator, and determines
the rotating direction of motor in either normal
rotation or reverse rotation. Then as the motor
rotates, the contact point is moved, and when
the contact point is detached or the output
signal of control unit turns OFF, the motor
stops rotating.
25-39
(5) The actuator for inner and outer

The actuator for inner and outer air flow select
is installed on the blower intake unit, and opens
and closes inner and outer air damper through
the link. The actuator for inner and outer air
flow select contains position detection switch
which is switched with the movement of shaft
of the actuator. When the inner and outer
damper position is set by the inner and outer
switch on the control panel, the control unit
reads the signal of the position detection
switch in the actuator and determines the
rotation direction of motor in either normal
rotation or reverse rotation. Then as the motor
rotates, the position detection switch also
rotates and makes it stop at the set position
of the inner and outer air damper.
(6) Evaporator sensor

This sensor is used to control the evaporator
outlet temperature with the compressor
ON-OFF to protect the evaporator from freezing,
and this evaporator sensor functions as a
sensor of this control.
- Evaporator sensor inspecting items
(Specification)
Terminal resistanc:
at 0 degree C: 7.2 kilo-ohms
at 25 degree C: 2.2 kilo-ohms
(7) Dual pressure switch

This dual pressure switch is attached on L-hose and is used to turn OFF the compressor, and
employs dual type (for high and low pressure control) to protect the cooler cycle from possible failure
at the time when abnormal pressure was generated on the high pressure side.
(8) Solar radiation sensor

This solar radiation sensor, which is used to
correct the solar radiation to the auto air
conditioner detects the strength and solar
orientation of sunbeam after transforming them
into current by means of photo diode.
Inspection: Check for the continuity between
terminals.
25-40
25.8 TROUBLESHOOTING
25
25-41
25-42
25
25-43
25-44
25
25-45
25-46
25
25-47
25.9 SELF DIAGNOSIS FUNCTION ON DISPLAY OF PANEL
The failure of motor actuator and each sensor can be identified on the display of panel.
25.9.1 POSITION OF INDICATION FOR FAILURE
25.9.2 EXPLANATION OF INDICATION FOR FAILURE

(1) Failure of Motor Actuator
25-48
(2) Failures of sensors
25
(3) Communication error of control amplifier and panel
25-49
25.9.3 EXPLANATION OF MONITOR MODE

When error of 25.9.2 (2) sensors is displayed, the monitor mode is available to identify the sensor
condition (disconnection, short circuit).
(1) Position of monitor mode indication
(2) Operation of monitor mode
1.
Press inner and outer air flow select switch and ON/OFF switch simultaneously for 1 second.
2.
Press AUTO switch.
(After all segments are lit on for 1 second, the mode is switched into monitor mode.)
3.
Any figures of figures from 0 to 9 or any letters of alphabet from A to F are displayed on the 3rd
digit and 2nd digit of segment in three digits. The 1st digit is indicated by "H".
4.
Any digit indicated by one of figures 0 to 2 for the exclusive segment in three digits is selected by
pressing UP or DOWN of blower switch, and the required sensor is selected from the list below.
25-50
5.
The monitor display is terminated by pressing the inner and outer air flow select switch (R/F) and
ON/OFF switch for 1 second again, or turning off the main switch of excavator.
25
1.
The air conditioner is turned off while the monitor mode is in operation, and all switches are not
available for operation and setting until the monitor mode is cancelled.
2.
Even if each sensor is corrected while the monitor mode is in operation, the error display is
memorized. Therefore turn on ON/OFF switch again, and the error display is disappeared.
(3) Contents of monitor mode display

Refer to the list of segment display exclusively used for monitor and the list of segments in three
digits.
1. Example 1
2. Example 2
3. Example 3
25-51
4. List of 3 segments
25-52
［31. DISASSEMBLING AND ASSEMBLING］
31. DISASSEMBLING AND ASSEMBLING

TABLE OF CONTENTS
31.1 EXPLAINING CHAPTER OF WHOLE DISASSEMBLY & ASSEMBLY ………………………………31-3

31.1.1 FORM FOR CHAPTER OF DISASSEMBLY & ASSEMBLY ………………………………………31-3
31.1.2 INDICATION OF TIGHTENING TORQUE ……………………………………………………………31-3
31
Book Code No. S5YN3129E01
31-1

SK200-8 : YN12-56001~ S5YN3129E01
First Edition December, 2008
SK210LC-8 : YQ12-08001~ (SE Asia & Oceania)
August, 2009 SK80MSR-2 : LF06-04501~

(Oceania)
SK225SR : YB06-03501~
September, 2009
SK225SRLC : LA06-02501~ (OCE)
November, 2009 SK850LC : LY02-00151~

(SE Asia)
SK140LC-8 : YP09-T0101~
February, 2010 SK130-8 : LP09-T0101~
(TKCM)
SK130L-8 : LX07-T0101~
June, 2010 SK80CS-2 : LF06-04501~

(NA)
E80BMSR : LF06-04501~
(NHK)
E70BSR : YT06-18001~
(NHK-EUR)
SK70SR-2 : YT06-18001~
(NA)
July, 2010 E135BSRLC : YH06-08001~

(NHK-EUR)
SK140SRLC : YH06-08001~
(NA)
SK460-8 : LS11-02501~
August, 2010 SE Asia & India
SK480LC-8 : YS11-02001~
(HS Engine)
E235BSR(N)LC : YU06-03001~
(NHK-EUR)
SK235SRLC-2 : YU06-03001~
(NA)
E225BSR : YB06-03501~
E225BSRLC : LA06-02501~ (NHK-EUR)
SK215SRLC : LA06-02501~
(NA)
September, 2010 E385CLC : YC

(NHK)
SK350LC-9 : YC
(NA)
SK330-8 : LC11-T0101~
SK350LC-8 : YC11-T0101~ TKCM (HS Engine)
SK350LC-8 : YC11-T0101~
(TKCM)
October, 2010 SK80MSR-2 : LF06-04547~

(AUS)
SK70SR-2 : YT06-18444~
(AUS)
31-2
31.1 EXPLAINING CHAPTER OF WHOLE DISASSEMBLY &

ASSEMBLY
31.1.1 FORM FOR CHAPTER OF DISASSEMBLY & ASSEMBLY

This chapter is consist of 3-Section as follows.
(1) ATTACHMENTS : Chapter 32

1) Removing and Installing
2) Disassembling and Assembling
a. Cylinder
(2) UPPER STRUCTURE : Chapter 33
a. Hydraulic pump
b. Control Valve
c. Pilot Valve (ATT)
d. Pilot Valve (Travel)
e. Slewing Motor
f. Swivel Joint
(3) TRAVEL SYSTEM : Chapter 34
a. Travel Motor
31.1.2 INDICATION OF TIGHTENING TORQUE

Tightening torque is indicated as follows, for example ;
T=98N-m(72 lbf-ft)
Tolerance is to 10% unless otherwise specified.
・ Refer to "Chapter 11 TOOLS" for standard tightening torque.
31
31-3
31-4
［32. ATTACHMENTS］
32. ATTACHMENTS
TABLE OF CONTENTS
32.1 REMOVING AND INSTALLING ………………………………………………………………………………32-3

32.1.1 ATTACHMENT ASSY ……………………………………………………………………………………32-3
32.1.2 BUCKET ……………………………………………………………………………………………………32-3
32.1.3 ARM …………………………………………………………………………………………………………32-6
32.1.4 BOOM ………………………………………………………………………………………………………32-9
32.1.5 DOZER ………………………………………………………………………………………………………32-14
32.2 DISASSEMBLING AND ASSEMBLING ……………………………………………………………………32-15
32.2.1 CYLINDER …………………………………………………………………………………………………32-15
32
32-1

S5YT3215E01
(AUS)
PREFACE
(1) This Manual describes all the procedures from removing to attaching, arranging them by item.
(2) This Manual consists of 32.1 sections. "Removing and Installing", and 32.2 "Disassembling and
Assembling".
(3) The removing and installing can be performed in the procedure specified in Table of Contents,
but in view of actual repairing or time saving some process can be omitted.
(4) The removing and installing procedure does not completely cover all possible situations because of
differences of field condition and defective section.
(5) Please be aware that the procedure to be followed must be determined according to the above
conditions.
When disassembly and assembly are required, select the necessary section, itemize the work
contents with good understanding, then starts working.
32-2
32.1 REMOVING AND INSTALLING
32.1.1 ATTACHMENT ASSY
Front attachment and position
32.1.2 BUCKET
32.1.2.1 REMOVING BUCKET
(1) Put the machine in position to remove
bucket.
Position to remove bucket
(2) Removing pin (2)

Expand slit of ring (1) with screwdriver, and
remove it. Push out the pin (2) with
flat-blade screwdriver .
32
Removing pin (2)
32-3
(3) Removing bucket attaching pin (K)

Lift up bucket, position it so that bucket
attaching pin (K) is not loaded, adjust
bucket link, and pull out bucket attaching
pin (K).
Removing bucket attaching pin
(4) Removing bucket drive pin (J)

Put bucket on the ground, position it so
that the bucket drive pin (J) is not loaded,
adjust bucket link, and pull out pin (J).
Store the removed pin (J) in original
position again.
Removing bucket drive pin
32.1.2.2 ATTACHING BUCKET

(1) Attaching bucket drive pin (J)
Attach bucket drive pin (J) first, then
continue in the reverse procedure of
removing.
Attaching bucket
-When aligning the pin holes, do not put your finger in the pin holes, but align them visually.
-Check the seals for damaged and replace as necessary.
-When inserting the pin, coat the shaft with grease.
32-4
32.1.2.3 PROCEDURE FOR ADJUSTING CLEARANCE

Adjustment of clearance between bucket and arm
(1) Shift O-ring (3) toward the bucket boss,

using a spatula. (a-->b)
(2) When adjusting clearance (B), bring the
non-adjusting side of the bucket in contact
with the arm.
(3) Measure clearance (B) and check that it is
within 1.0 mm (0.04 in).
(4) Adjust clearance (B) where it is more than
1.0 mm (0.04 in).
(5) An average of 5 shims (8) of 1mm
(0.04in) thickness are set in the plate (6)
fixed by the three capscrews (10). The
clearance can be decreased by 1mm Adjusting clearance between bucket and arm
(0.04in) if one shim is removed.
Tools: Socket: 19 mm,
Tightening torque : 279 N-m (206 lbf-ft)
(6) After adjustment, tighten the capscrews
evenly.
-The gap exceeding the specified dimension
causes early wear.
(7) Operate the bucket and confirm that the
total sum of both clearance is within 1.0
mm (0.04 in).
(8) Replace O-ring (3) on its original position.
-When shifting O-ring (3) by means of a spatula, use care so as not to damage O-ring (3).
-Remove shims (8), push out bushing (7) rightwards by means of three capscrews (10) and adjust
clearance (B) so it settles within the standard value evenly all round.
-Check the clearance at 120 hours' intervals in normal operation. Shorten these intervals in special
hard operation. Adjust the intervals as necessary.
32
32-5
32.1.3 ARM
32.1.3.1 REMOVING ARM
(1) Put the machine in position to remove arm.
Extend the arm cylinder, retract the bucket
cylinder and bring the arm down on the
ground.
Position to remove arm
(2) Disconnecting piping of bucket cylinder

Release pressure of hydraulic tank, place
oil pan to prepare for oil leaking, and
disconnect pipes.
When the removal of bucket cylinder is
not required, skip to procedure (6).
Disconnecting piping of bucket cylinder
Plug both end of disconnected pipes.

Plug:
Tools section 11.5.2-(4)
(3) Removing bucket cylinder rod pin (H)

1. Loosen nut (8), remove capscrew M12X100 (7), and push out pin (H).
Tools: Spanner: 19mm
2. Retract cylinder rod.
Detail of bucket cylinder rod pin (H)
32-6
(4) Removing cylinder head pin (G)

Loosen nut (3), remove capscrew
M12X100 (2), and push out pin (G).
Detail of bucket cylinder head pin (G)
(5) Removing bucket cylinder

Sling tube of bucket cylinder with nylon
sling, and remove it.
Bucket cylinder weight: 50 kg (110 lbs)
Slinging bucket cylinder
(6) Removing arm cylinder rod pin (E)

Loosen nut (3), remove capscrew (2), and push out arm cylinder rod pin (E).
Retract arm cylinder rod, and return pin (E) to the original position (hole).
Detail of arm cylinder rod pin (E)
32
32-7
(7) Removing boom top pin (F)

Loosen remove capscrew (2), and pull out
boom, top pin (F).
Put block between arm cylinder and boom.
Insert pin (F) into the original hole.
Detail of boom top pin (F)
(8) Slinging arm assy

Sling arm with nylon sling and remove it.
Arm weight:
230 kg (507 lbs) (with bucket cylinder)
180 kg (397 lbs) (without bucket cylinder)
Slinging arm assy
32.1.3.2 ATTACHING ARM

Instal the arm in the reverse order of removing, paying attention to the following:
1. When aligning the pin holes, do not put your finger in the pin holes, but align them visually.
2. Check the seals for damage and replace as necessary.
3. When inserting the pin, coat the shaft with grease.
4. Pin lock nut handling procedure

5. When installing the arm and the cylinder,
inspect the clearance in the thrust
direction of the pins and decide the
thickness of shims by referring to the
Maintenance Standard.
6. Tightening torque
32-8
32.1.4 BOOM
32.1.4.1 PREPARATION FOR REMOVING AND ATTACHING BOOM
When removing and attaching boom in the position shown in below Fig. to remove and attach boom
foot pin (A), removing and attaching of cab and guard are required.
32.1.4.2 REMOVING BOOM

(1) Put the machine in position to remove
boom.
Place top end of boom down on block, etc.
giving attention for arm cylinder rod not to
be extended.
Position to remove boom
(2) Lifting up boom cylinder temporarily

Lift up boom cylinder temporarily to
prevent it from dropping.
Lifting up boom cylinder temporarily
(3) Removing boom cylinder rod pin (C)

Loosen nut (7), remove capscrew (3), and
push out pin (C).
(4) Preparing for separating cylinder pipes
Retract boom cylinder rod side, and place
one side of cylinder on block (See Fig.
"Lifting up boom cylinder temporarily")
Detail of boom cylinder rod pin (C) 32
32-9
(5) Separating piping of arm cylinder and bucket cylinder

Release pressure in hydraulic tank, and separate pipe at section E-E.
After separation of pipe, plug every pipe.

Plug : Tools section 11.5.2-(4)
Boom piping disconnection
(6) Lifting up boom assy temporarily

Lift up boom cylinder with nylon sling so that boom foot pin (A) is not loaded.
Weight of boom assy : 530 kg (1169 lbs)
Boom assy temporarily lift up procedure
32-10
(7) Removing boom foot pin (A)

1.
Remove snap pin (3) and pull out pin (2).
2.
Tools to Thread M16 X 54 for pin (1) :
Screw slide hammer in
Refer to Tool 10. Tools for boom attaching
pin.
3.
Force slide hammer in until the pin is out.
Details of boom foot pin (A) section
(8) Slinging boom assy

Sling and remove boom assy.
Weight of boom assy : 530 kg (1169 lbs)
Boom assy slinging procedure
32
32-11
(9) Completion of removal of front attachments

When the removing and attaching of
cylinder are not required, the work is
finished.
(10) Removing arm cylinder
Disconnect hose at A section, and plug
both ends.
Plug: TOOLS
11.5.2-(4) Plugs for ORS fitting
(11) Removing arm cylinder head pin (D)
Loosen nut (3), remove capscrew (2) and
pull out pin (D).
Removing arm cylinder (2).
Weight of arm cylinder: 70 kg (150 lbs) Removing arm cylinder
(12) Removing boom cylinder

Disconnect hose at B section. Plug both
ends.
plug : Tools section 11.5.2-(4)
(13) Removing boom cylinder foot pin (B)
Loosen capscrew (4) and pull out pin (B).
Removing boom cylinder
32-12
32.1.4.3 ATTACHING BOOM

(1) Attaching boom foot pin (A)
Screw tool 10. slide hammer M16 into boom foot pin (A) first, and fit boom assy.
Attach it in the reverse procedure of removing paying attention to the following points.
1. When aligning the pin holes, do not put

your finger in the pin holes, but align them
visually.
2. Check that the dust seals is not damaged
and replace as necessary.
3. When inserting the pin, coat the shaft with
grease.
4. M12 Tightening torque : 115 N-m (85 lbf-ft)
Boom cylinder head pin (B)
5. Pin lock nut handling procedure
6. To attach shim, fit resin shim on operating

side and iron shim on the outside, and
reduce the space.
Attaching boom cylinder head pin
32
32-13
32.1.5 DOZER
32.1.6.1 REMOVAL
(1) Put a support of appropriate height under
the mounting side of dozer body, and make
the dozer at a stable condition not to
exert any load to the pin (P).
(2) Disconnect the hydraulic hoses and apply a
plug to the connecting portions.
Tools : Spanner : 22mm
(3) Apply a nylon sling to the dozer cylinder
(C1), and lift it up slightly not to exert any
load to the pin (Q) of rod side. Removing / Installing Dozer
(4) Remove the capscrew (C2) and nuts (C3)
those are preventing the pin (Q) from
coming out. Remove the pin (Q), and
support the cylinder (C1) with wood block,
etc.
(5) Remove the capscrew (B2) and nuts (B3)
that are preventing the dozer body fixing
pin (Q) from coming out, and remove the
two pins (P).
(6) Gradually move the machine to backward
to remove the dozer.
Weight of dozer assy : 339kg (748 lbs)
(7) If necessary, remove the dozer cylinder by
means of removing the pin (R) of head
side.
Weight of dozer cylinder : 51kg (112 lbs)
32.1.6.2 INSTALLATION
The installation is carried out with the reverse order of the removal paying attention for the following.
(1) Referring to the Section "ATTACHMENT

DIMENSIONS" of Specifications, replace the
worn-out bushings and dust seals to new
ones.
(2) Before installing pin (P), (Q) and (R),
apply grease to their shaft area.
(3) Referring to right Fig., install the nuts for
capscrew to prevent the pin from coming
out.
Tools : Spanner : 19mm Tightening Procedures for Nuts
32-14
32.2 DISASSEMBLING AND ASSEMBLING
32.2.1 CYLINDER
32.2.1.1 PREPARATION BEFORE DISASSEMBLY
Before disassembly, secure a dustfree workshop and necessary equipment and facilities.
32.2.1.1.1 WORK AREA

The following working area is required for disassembly:
(1) Ample space
For the disassembly of the hydraulic cylinder, the cylinder tube and the piston rod must be drawn
out. For this reason, the first condition is that the working area is long enough for the work. In
terms of width, it is also necessary to keep sufficient space to disassembly, cleaning and
measuring equipment are placed and the work can be performed.
(2) Suitable working environment
The hydraulic cylinder is a precision-machined product that uses seals and packings made of
rubber and plastic materials. For this reason full care should be exercised so the hydraulic cylinder
is free from dust, dirt, and in particular, such hard particles as sand, metal chips, and weld slag
(spatter). If the hydraulic cylinder is assembled with hard particles adhered on such components
as the cylinder tube and the piston rod, the tube inner surface and the rod surface are scratched
as the cylinder operates, consequently disabling it in worst cases. Damage to the piston seals
and the rod seals will result in oil leaks. For this reason, grinding and welding operation should
not be performed in the neighborhood of the working area to keep it clean.
32.2.1.1.2 APPARATUS
The following equipment are required for disassembly:
(1) Hoist or crane
The hoist or crane must be capable of carrying the cylinder in an assembled condition. It must
also be capable of making level and liner movement under load for retracting and extending the
piston rod and the tube.
(2) Work bench
The work bench must have strength and rigi-dity capable of accommodating the total length of
the cylinder in its most retracted condition and of withstanding the repulsive force of the
tightening torques of the cylinder head and the piston nut. Since a vise is attached to the bench,
the width of the work bench must be sufficiently large.
(3) Support stand
If the piston rod is fully extended in a free condition, the bushing and the seals may be
damaged as the rod bushing and the piston are twisted due to the weight of the rod. A stand is
required to support the rod to prevent damage of seals.
(4) Hydraulic source
A Hydraulic source is required for disassembly and assembly of the cylinder head and piston nut
and for oil leak tests after completion of assembly. 32
(5) Jet air source
It is used for drying after oil draining and cleaning of the cylinder.
(6) Cleaning bath, cleaning oil and detergent
(7) Oil pan and oil reservoir
An oil pan is necessary to contain oil drained from the cylinder and oil spilt during work.
(8) Others
Oil extracting hoses, wooden blocks, clean cloths and sawdust in which oil soaked are also
necessary.
32-15
32.2.1.1.3 NECESSARY TOOLS

List of Tools and Jigs
Tool/Jig Remarks Tool/Jig Remarks
Hammer 1. Steel hammer Spatula Metallic one with smooth corners.
2. Wooden or plastic hammer
Screwdriver A few types of large and small sizes Gimlet A sharp-point tool may be used in
place of a gimlet.
Chisel Flat chisel Special jig 1. For fitting seal ring
2. For pushing seal ring
3. For inserting bushing
4. For press-fitting wiper ring
Vise One having an operation wide enough to Rust
hold cylinder head O.D. and tube remover
mounting pins (clevis)
Wrench 1. Eye wrench Measuring 1. Slide caliper
2. Allen wrench instruments 2. Micrometer
3. Extension pipe for wrenches 3. Cylinder gauge (Fig. "Cylinder gauge")
4. V-block
・ For the details of special tools and jigs, refer to the back pages of this manual.
32.2.1.1.4 EXTERNAL CLEANING

The cylinder taken off the excavator has dust
and foreign matter, and grease is usually
adhered to the clevis part. For this reason,
Cylinder gauge
remove external soil and contamination from the
cylinder with water and steam before bringing
it into the workshop.
-The following describes the construction of
arm cylinder (with cushions on both sides).
When disassembling and servicing the cylinder,
confirm the construction of cylinder referring to
Parts Manual.
32.2.1.1.5 DISCHARGING OIL

Place a wooden-block on the work bench and
place the cylinder on it to prevent it from
rotating. Charge air into ports A and B
alternately to actuate the piston rod till the
hydraulic oil in the cylinder is drained out. At
this time, connect a suitable hose to each port
so that the hydraulic oil may not gush out.
Preparation
32-16
32.2.1.2 CONSTRUCTION OF CYLINDER (AN EXAMPLE OF ARM CYLINDER)
Construction of cylinder (An example of arm cylinder)
No. NAME Q'ty No. NAME Q'ty No. NAME Q'ty

1 CYLINDER TUBE ASSY 1 11 O-RING 1 21 CUSHION BEARING 1
2 PISTON ROD ASSY 1 12 HOLDER 1 22 CUSHION SEAL 1
3 ROD COVER 1 13 BACKUP RING 1 23 STOPPER 2
4 BUSHING 1 14 CUSHION BEARING 1 24 SNAP RING 1
5 SNAP RING 1 15 CUSHION SEAL 1 25 PIN BUSHING 4
6 BUFFER RING 1 16 PISTON 1 26 WIPER RING 4
7 U-RING 1 17 SEAL RING ASSY 1
8 WIPER RING 1 18 SLIDE RING 2
9 O-RING 2 19 SET SCREW 1
32
10 BACKUP RING 1 20 STEEL BALL 1
32-17
32.2.1.3 DISASSEMBLY
・ Before starting disassembling and servicing, confirm the construction and supply parts referring to
Parts Manual in the separate volume, and also required tools and jig.
・ Figures noted just after the "Part name" correspond to the number stated in Fig. "Construction of
cylinder (An example of arm cylinder)". Other cylinders may have some different parts.
32.2.1.3.1 REMOVING ROD COVER AND PISTON ROD

(1) Fix the tube installing pin side using a vise. (Refer to 32.2.1.1.5 "Preparation".)
Take care not to damage the cylinder tube and machined surface.
Never use external pipe to stop turning.
(2) Pull piston rod (2) out about 200 mm (8

in).
Use air to push piston rod (2) out after
draining the oil because of the weight of
piston rod (2).
(3) Flatten the lock on slit section installed
between rod cover (3) and cylinder tube (1) Removing piston rod
with chisel and hammer.
(4) Lift up cylinder rod section with nylon sling
temporarily.
(5) Then, Hook a hook wrench to rod cover
(3), turn it counterclockwise and remove it.
Special tool : Refer to 32.2.1.8(7).
(6) After putting threads out of mesh, remove
the end of rod cover (3) using plastic
hammer.
Flatten the slit lock
Removing rod cover
Pulling piston rod out
In this case, apply the hoisting force equivalent to the weight of piston rod, because the weight of
piston rod weights upon the rod cover.
32-18
(7) Place pulled out piston rod assy (2) on

the wooden V-block horizontally.
Placing piston rod assy
(8) Remove slide ring (18).
Removing slide ring
32.2.1.3.2 REMOVING PISTON ASSY

(1) Fix piston rod (2) grasping the installing pin
portions with vise. Then fix it in strength so
that it can withstand the tightening torque
for piston rod (2) because the piston rod
(2) is secured with large tightening torque.
Fixing piston rod assy
(2) Shave off the caulked section on set

screw (20) with hand drill, loosen set screw
and take out steel ball (21).
Removing setscrew
(3) Remove nut section of piston with a

closed wrench.
Special tool : See 32.2.1.8 (8)
-Since the piston section (16) is tightened 32
by high torque, use the closed wrench
closely fitted to the width across flat.
-Approx. 1.5 times or higher of torque is
required to loosen piston nut. So prepare
Removing piston nut
power wrench equipped with hydraulic jack
or hydraulic cylinder, if possible.
32-19
(4) Removing cushion bearing on the retraction

side.
1.
Remove snap ring (24). Strike it lightly
being careful not to damage cushion
bearing and piston rod.
2.
Move cushion bearing (21) to threaded
side, and remove stopper (23) (two pieces
type).
3. Disassembling cushioning bearing
Pull out cushion bearing (21).
4.
Expand slit (1 place) of cushion seal (22)
and remove it.
(5) Removing cushion bearing on extension

side.
1.
Pull out cushion bearing (14).
2.
Expand slit (1 place) on cushion seal (15)
and remove it.
Disassembling cushioning bearing
32.2.1.3.3 DISASSEMBLING PISTON ASSY

Removing piston seal
(1) Remove slide ring (18) by hand.

(2) Cut seal ring (17) with driver (-) and
hammer as shown in the right figure.
(3) Pull out O-ring with spatula.
(4) Strictly prohibited to use pulled out seal
parts.
Disassembling piston assy
32-20
32.2.1.3.4 REMOVING ROD COVER ASSY

Remove rod cover assy from piston rod (2). If it
is too difficult to remove, strike flange section of
rod cover (3) with plastic hammer.
Hang the rod cover assy with crane and
remove it straight horizontally.
Removing rod cover assy
Care should be taken not to damage the bushing (4) lip section of link and seal with screw of piston
rod (2) when pulling out rod cover (3).
32.2.1.3.5 DISASSEMBLING ROD COVER ASSY

(1) Removing buffer ring
1. Buffer ring (6) (Teflon made seal) is fitted
on the inside of rod cover (3). Pierce with
pointed tool on the seal, raise it, insert
spatula and take it out.
-Strictly prohibited to use the removed seal.
Construction of rod cover assy
(2) Removing U-ring (7) and wiper ring (8)

1. Remove U-ring (7) with driver, etc.
2. The wiper ring (8) is press-fitted.
Pierce with driver, etc. on rubber and
strike and remove it with driver.
-Strictly prohibited to use removed seal.
32
Direction of buffer ring
32-21
(3) Removing bushing (4)

Raise snap ring (5) with hooked bar and take it
out from cylinder rod cover. And press out
bushing (4) with jig. If it is too difficult to take it
out with jig, use lathe to remove it.
Removing bushing
(4) Removing pin bushing

1. Remove wiper ring (26).
2. The pin bushing (25) of piston rod (2) is
pressfitted, so press it out with a press
applying a plate to the section.
Drawing out pin bushing (rod & tube)
Where it is impossible to press it out, cut it with gas burner.
(5) Cleaning
1. After completion of cylinder disassembly, clean all the parts with detergent.
Apply hydraulic oil on them and cover them to store.
Leaving them in the as-disassembled condition causes rust, adherence of dust, etc., which may
cause malfunction after assembling.
2. Replace all of U-ring, wiper ring, O-ring and backup ring as a general rule.
Do not use volatile agents (gasoline and thinner) as they deteriorate rubber.
32-22
32.2.1.4 INSTALL
・ Cylinder tube assy
・ Piston rod assy
・ Rod cover assy
・ Piston assy
32.2.1.4.1 ASSEMBLING CYLINDER TUBE ASSY, PISTON ROD ASSY

(1) Apply hydraulic oil on the head in which
pin bushing is inserted and on the pin
bushing hole of rod.
(2) Press pin bushing (26) into cylinder tube
(1) and piston rod (2), using a press.
(3) Insert wiper ring (27) in both sides.
Pressing in pin bushing (rod & tube)
32.2.1.4.2 ASSEMBLING ROD COVER ASSY

(1) Press fit bushing (4) in rod cover (3)
applying plate on the section. After
press-fitting, check that the bushing is not
projected from the end surface (A). (See
right Fig.)
Pressing in bushing
32
32-23
(2) Fit snap ring (5).

(3) Apply hydraulic oil on U-ring (7) and fit it
on the U-ring groove.
Fitting U-ring
-The U-ring is harder than other seals, so fit it in the groove by hand first, then press in with pushing
bar until it is fitted with a click.
-Fitting U-ring paying attention to the direction.
-After fitting U-ring (7), check that they are free from the permanent set.
(4) Installing buffer ring assy

Buffer ring assy (6) is equipped with square
ring and slide ring.
1. Fit square ring on the groove.
2. Depress slide ring in U shape by hand
to house it in groove, and fit it pushing
out to periphery.
Installing buffer ring assy (6)
-Depress it R 6 mm (0.24 in) or more, because if the depressed R is too small, it may remain
wrinkled.
-After fitting, check that it is free from wrinkles.
-Fit it giving attention to the seal fitting direction. Reverse fitting produces high pressure between U-ring
and seal and may cause the deformation of rod cover.
-Fit slide ring so that the groove matches to the root section of square ring.
32-24
(5) Press fit wiper ring (8) by means of Jig

32.2.1.8(4).
Pressing in wiper ring
(6) Fit backup ring (10) and O-rings (9), (12).

(Attention should be paid to the fitting
order.)
Fixing back-up ring and O-ring
32.2.1.4.3 ASSEMBLING PISTON ASSY

(1) Installing seal ring assy
1. Fit O-ring so as not to be distorted.
2. Press in seal ring (17) referring to Jig
32.2.1.8(1), (2).
Installing the seal ring (17)
3. Since the seal ring (17) is extended when

fitting, press it referring to Correction jig
32.2.1.8(5).
32
Correcting the seal ring (17)
32-25
4. Fitting slide ring (18)

Fit it from rod side expanding slit by both
hands.
-Expand slit in minimum.
If expansion is exceeded, the ring cannot
be fitted.
-Slit is mutually shifted 90 degree.
Installing the slide ring (18)
32.2.1.4.4 INSTALLING ROD COVER ASSY ON ROD

(1) Fix piston rod assy on work bench.
(2) Apply grease (or hydraulic oil) on outside of
piston rod (2), inner surface of buffer ring
(6), U-ring (7), wiper ring (8) and bushing
(4), and slide rod cover assy on piston
rod (2) taking care not to damage the lip
of wiper ring (8). Installing rod cover assy
It may not slide smoothly due to frictional
resistance of U-ring. In this case, sling rod
cover assy horizontally with crane, and
push it striking flange of rod cover with
mallet.
Pressing rod cover
While pushing, be careful that the rod cover assy is not rotated to piston rod (2).
32-26
32.2.1.4.5 INSTALLING PISTON ASSY ON ROD

(1) Fitting cushion bearing (14) on the extension side
Before attaching piston (nut ) (16), fit cushion bearing (14). If the piston nut is attached, the bearing
can not be fitted.
1. Expand slit of cushion seal (15) and insert

it into groove piston rod (2).
2. Fit cushion bearing (14).
Fitting cushion bearing (14) on the extension

side
-Insert cushion seal (15) directing the cut out toward the thread side of rod as shown in Figure.
-Fit cushion bearing (14) directing the flat section toward as shown in Figure.
(2) Fitting cushion bearing (21) on retraction side

1. Fit cushion seal (22) in groove directing the
cutout toward the thread side.
2. Assemble cushion bearing (21) directing the
flat section toward as shown in Figure.
3. Fit stopper (23) in groove.
4. Push cushion bearing (21) to stopper (23)
fully, and strike and fit snap ring (24).
Fitting cushion bearing (21) on retraction side
Strike snap ring with plastic hammer being careful not to damage rod (2) and cushion bearing (21).
32
32-27
(3) Tightening piston nut

1. Insert piston (nut) (16) into rod, and
tighten piston (nut) (16) to the specified
torque.
Special tool : See Table 32-12
Tightening torque : Refer to 32.2.1.7(1).
Tightening piston nut (16)
2. Put steel ball (20) in and tighten setscrew

(19).
Tools: Allen wrench,
Tightening torque : Refer to 32.2.1.7(2).
3. Caulk 2 places on outer surface with punch.
Caulking set screw of piston nut
32-28
32.2.1.4.6 OVERALL INSTALL

(1) Place a V-block on a rigid work bench (A
wooden V block is preferable.) Mount the
cylinder tube assy (1) on it and fix the
assy by barring a bar through the
attaching pin hole to lock the assy. (See
right Fig.)
(2) Insert piston rod (2) into cylinder tube (1)
while hanging and moving it with crane.
Then, apply hydraulic oil on tube lip inner
side and piston outer surface and insert
horizontally aligning the center of piston rod
and center of cylinder tube.
-Also, the use of fork lift makes inserting Installing piston rod
easier.
-Insert piston into tube being careful that
seal ring and slide ring are not caught in
the stepped section of tube.
(3) Apply Three Bond #1901 on thread

section of rod cover and hydraulic oil on
O-ring (12), rotate rod cover assy (3) by
hand. Screw in 2 or 3 threads first, then
tighten it to the specified torque with hook
spanner wrench.
(4) Bend slit of cylinder tube toward cutout of
rod cover (3) to lock. Bending lock of slit
32
32-29
32.2.1.5 MAINTENANCE STANDARDS

(1) Inspection after disassembly
1. Inspection
Parts Name Inspecting Portion Inspection Item Remedy

1. Neck of rod pin Presence of crack Replace
2. Stepped part to which
Presence of crack Replace
piston is attached
3. Threads Presence of seizure Recondition or replace
4. Bend Measure degree of bend Refer to rod bend
5. Plated surface Check that:
Piston rod 1) Plating is not worn off to 1) Replace or replate
base metal
2) Rust is not present on 2) Replace or replate
plating.
3) Scratches are not present 3) Recondition or replace
6. Rod Wear of O. D. Recondition or replace
7. Bushing at mounting part Wear of I. D. Replace
1. Weld on bottom Presence of crack Replace
2. Tube at mounting part Presence of crack Replace
Cylinder tube
3. Tube interior Scratches are not present Replace if oil leak is seen
4. Bushing at mounting part Wear of I.D. Replace
1.Bushing 1) Wear on inner surface
Rod cover Replace
2) Flaw on inner surface
(2) Maintenance standards

Replace sliding parts and seal parts according to the following.
1. Bushing: Where 1/4 of circumference is worn in red copper color.
2. Seals and slide ring: Replace them when cylinder is disassembled.
3. Pin bushing: Where severe scuffing is produced.
4. Piston rod: Where the bent 0.5 mm/m (0.02 in / 3.37 in) or more is produced.
(3) Inspection after assembling

No-load performance When operating 5 time or more in full stroke at no-load, it operates smoothly with no
inspection abnormality.
Dimensional inspection Check the fully retracted length and stroke specified in drawing.
After applying test pressure specified in drawing to each stroke end for 3 minutes or
Pressure inspection
more, it is free from loosening, permanent set and oil leaking.
No-load performance Check rod section for oil leaking.
inspection (Refer to Criterion of oil leak quantity on rod section in proceeding page.)
Oil leak quantity unit mL (cc) / 10min
Oil leak Oil leak Oil leak
I. D. mm (in) I. D. mm (in) I. D. mm (in)
quantity quantity quantity
Internal leakage 32 (1.26) 0.4 100 (3.94) 4.0 160 (6.30) 10.0
inspection 40 (1.57) 0.6 125 (4.92) 5.6 180 (7.09) 12.6
50 (1.97) 1.0 140 (5.51) 6.0 200 (7.87) 15.6
63 (2.48) 1.6 220 (8.66) 20.0
80 (3.15) 2.3 250 (9.84) 22.0
32-30
(4) Criterion of oil leak quantity on rod section

Determine according to the oil ring condition produced on rod after 20 strokes in oil temperature 20
degC (68 degF) to 40 degC (104 degF). When oil ring is changed to A condition, it is in abnormality.
Refer to 32.2.1.9 "Troubleshooting", and take a measure.
Oil ring condition on rod section
32.2.1.6 GENERAL TOOL
32
32-31
32.2.1.7 TIGHTENING TORQUE

(1) Piston nut
(2) Setscrew
(3) Rod cover
(4) For piping
32-32
32.2.1.8 TOOL AND JIGS LIST

(1) Seal ring fitting jig ( I )
Material : Mild steel
Unit: mm(in)
Applicable
D0 D1 (D2) D3 L0 (L1) L2
cylinder
Boom 111 (4.3701) 110 (4.3307) 86 (3.39) 96 (3.78) 100 (3.94) 72 (2.83) 24 (0.9449)
Arm 96 (3.7795) 95 (3.7401) 71 (2.80) 81 (3.19) 100 (3.94) 72 (2.83) 23 (0.9055)
Bucket 81 (3.1890) 80 (3.1496) 56 (2.20) 66 (2.60) 100 (3.94) 72 (2.83) 20 (0.7874)
Dozer 121 (4.7638) 120 (4.7244) 96 (3.78) 106 (4.17) 100 (3.94) 72 (2.83) 24 (0.9449)
(2) Seal ring fitting jig ( II )

Material : Nylon or acrylic resin
Unit: mm(in) 32
Applicable
D0 D1 L
cylinder
Boom 112 (4.41) 104 (4.09) 100 (3.9370)
Arm 97 (3.82) 89 (3.51) 100 (3.9370)
Bucket 82 (3.23) 74 (2.91) 100 (3.9370)
Dozer 122 (4.80) 114 (4.49) 100 (3.9370)
32-33
(3) Bushing press-fit jig

Unit: mm(in)
Applicable
D0 D1 (D2) D3 L0 (L1)
cylinder
Boom 85 (3.3465) 79.5 (3.13) 78 (3.07) 105 (4.13) 65.5 (2.58) 59.5 (2.3425)
Arm 75 (2.9528) 69.5 (2.74) 68 (2.68) 95 (3.74) 65.3 (2.57) 53.3 (2.0984)
Bucket 60 (2.3622) 54.5 (2.15) 53 (2.09) 80 (3.15) 20.5 (0.807) 8.5 (0.3346)
Dozer 85 (3.3465) 79.5 (3.13) 78 (3.07) 105 (4.13) 25.5 (1.00) 13.5 (0.5315)
(4) Wiper ring (rod cover) press-fit jig

Unit: mm(in)
Applicable cylinder D0 D1 D3
Boom, Dozer 70 (2.7559) 78.5 (3.0905) 95 (3.74)
Bucket 55 (2.1654) 63.5 (2.5000) 80 (3.15)
Arm 65 (2.5591) 73.5 (2.8937) 90 (3.54)
32-34
(5) Seal ring straightening jig

Unit: mm(in)
Applicable
D0 (D1) L0 (L1)
cylinder
Boom 110 (4.3307) 130 (5.12) 120 (4.72) 40 (1.57)
Arm 95 (3.7401) 115 (4.53) 120 (4.72) 40 (1.57)
Bucket 80 (3.1496) 100 (3.94) 120 (4.72) 40 (1.57)
Dozer 120 (4.72) 140 (5.51) 120 (4.72) 40 (1.57)
(6) Piston insert jig

Unit: mm(in) 32
Applicable
øA øB øC D E
cylinder
Boom 122 (4.80) 110 (4.3307) 113 (4.4488) 67 (2.64) 42 (1.65)
Arm 107 (4.21) 95 (3.7401) 98 (3.8583) 67 (2.64) 42 (1.65)
Bucket 92 (3.62) 80 (3.1496) 83 (3.2677) 62 (2.44) 37 (1.46)
Dozer 132 (5.20) 120 (4.7244) 123 (4.8425) 62 (2.44) 37 (1.46)
32-35
(7) Hook wrench
Unit: mm (in)
Applicable
A B C t D r f L
cylinder
138
Boom 12 (0.4724) 5 (0.1969) 15 (0.591) 2 (0.0787) 86 (3.39) 12 (0.472) 380 (15.0)
(5.433)
120
Arm 12 (0.4724) 4.5 (0.1772) 15 (0.591) 2 (0.0787) 80 (3.15) 12 (0.472) 380 (15.0)
(4.7244)
104
Bucket 10 (0.3937) 4.5 (0.1772) 15 (0.591) 2 (0.0787) 68 (2.68) 9 (0.354) 320 (12.6)
(4.094)
140
Dozer 12 (0.4724) 5 (0.1969) 15 (0.591) 2 (0.0787) 93 (3.66) 12 (0.472) 460 (18.1)
(5.5118)
(8) Eye wrench
Unit: mm (in)
Applicable L=300 (11.8) L=500 (19.7)

Size A
cylinder B1 B2 t B1 B2 B3 t
Boom 80 (3.1496) 110 (4.33) 78 (3.07) 28 (1.10) 122 (4.80) 107 (4.21) 87 (3.43) 28 (1.10)
Arm 75 (2.9528) 95 (3.74) 67 (2.64) 25 (0.984) 104 (4.09) 90 (3.54) 78 (3.07) 25 (0.984)
Bucket 60 (2.3622) 95 (3.74) 67 (2.64) 16 (0.630) 104 (4.09) 90 (3.54) 78 (3.07) 16 (0.630)
Dozer 80 (3.1496) 110 (4.33) 78 (3.07) 28 (1.10) 122 (4.80) 107 (4.21) 87 (3.43) 28 (1.10)
32-36
32.2.1.9 TROUBLESHOOTING
Failure on hydraulic cylinder and corrective action
It is very difficult to find defective section. The following table explains general phenomenon, estimated
causes and corrective actions.
For repair, refer to the estimated causes and corrective actions.
However, Most machine problems are not caused by the failure of only one part, but involve relations
with other parts.
Therefore corrective action other than those described in Table is often required. Please contact us to
pursue the problems and causes further and to take appropriate corrective action.
Items Phenomenon
Oil leakage from piston rod sliding section
1
(For criterion, refer to 32.2.1.5(3).)
2 Oil leakage from rod cover set section
3 Oil leakage from pipe and cylinder tube weld zone
4 Malfunction
32
32-37
32-38
32
32-39
32-40
［33. UPPER SLEWING STRUCTURE］
33
33. UPPER SLEWING STRUCTURE

TABLE OF CONTENTS

33.1.1 OPERATOR SEAT…………………………………………………………………………………………33-3
33.1.2 CAB …………………………………………………………………………………………………………33-5
33.1.3 BATTERY ……………………………………………………………………………………………………33-8
33.1.4 GUARD ………………………………………………………………………………………………………33-10
33.1.5 UNDER COVER ……………………………………………………………………………………………33-14
33.1.6 FUEL TANK…………………………………………………………………………………………………33-15
33.1.7 HYDRAULIC TANK ………………………………………………………………………………………33-17
33.1.8 HYDRAULIC PUMP ………………………………………………………………………………………33-21
33.1.9 AIR CLEANER ……………………………………………………………………………………………33-24
33.1.10 MUFFLER …………………………………………………………………………………………………33-26
33.1.11 COUNTERWEIGHT ………………………………………………………………………………………33-28
33.1.12 RADIATOR & OIL COOLER……………………………………………………………………………33-29
33.1.13 ENGINE ……………………………………………………………………………………………………33-34
33.1.14 CONSOLE COVER ………………………………………………………………………………………33-37
33.1.15 CONTROL VALVE ………………………………………………………………………………………33-39
33.1.16 PILOT VALVE (FOR ATT) ……………………………………………………………………………33-41
33.1.17 PILOT VALVE (FOR TRAVEL) ………………………………………………………………………33-43
33.1.18 SWING MOTOR UNIT …………………………………………………………………………………33-44
33.1.19 SWIVEL JOINT……………………………………………………………………………………………33-46
33.1.20 UPPER FRAME …………………………………………………………………………………………33-49
33.2.1 HYDRAULIC PUMP - REGULATOR……………………………………………………………………33-52
33.2.2 CONTROL VALVE …………………………………………………………………………………………33-74
33.2.3 PILOT VALVE (FOR ATT) ………………………………………………………………………………33-90
33.2.4 PILOT VALVE (FOR TRAVEL) …………………………………………………………………………33-103
33.2.5 SWING MOTOR UNIT ……………………………………………………………………………………33-108
33.2.6 SWIVEL JOINT ……………………………………………………………………………………………33-124
33-1

S5YT3315E01
(AUS)
PREFACE
(1) This Manual describes all the procedures from removing to installing, arranging them by item.
(2) This Manual consists [Removing and installing], and [Disassembling and assembling].
(3) The removing and installing can be performed in the procedure specified in Table of Contents,
but in view of actual repairing or time saving some process can be omitted.
(4) The removing and installing procedure does not completely cover all possible situations because of
(5) Recognize well that the service man must decide a work procedure before proceeding to repair.
When deciding the work procedure, choose an item that is needed, familiarize yourself with the
contents of the work and itemize the work procedure, before starting work.
(6) Disconnect the negative terminal of battery first, when the removing and the installing of the
electric component and wiring are performed.
(7) The explanatory note and figure of this manual may differ from the actual machine by the
difference in specification.
33-2
33
33.1.1 OPERATOR SEAT
33.1.1.1 REMOVAL
(1) Preparation for removal
1. Remove the head rest (A1-1) of the operator's seat (A1) to ease handling.
2. Move the whole control stand to its foremost position.
3. Move the operator's seat to its forward end.
4. Incline the reclining seat as forward as possible.
(2) Remove operator's seat. (Include upper rail.)

1. With the above-mentioned condition, remove
two cap screws (B2) M8X20 from the upper
rail. Then move the control stand to its
rearmost end and remove two capscrews
(B2) M8X20.
2. Remove the operator's seat. [about 28 kg
(62 lbs).]
Carry out the following operations as
required.
3. Remove seat belt (C1), bracket (C2).
4. Remove armrest (A3)(A4).
5. Remove bracket assy (1), rail (7).
Disassembling and Assembling seat
33-3
Install it in reverse procedure of removing according to the tightening torque table.
Disassembling and Assembling armrest
Reference : Movement on rail

Upper rail.....Fixed on lower surface of seat
[Forward 80mm (0.26in), backward 80mm (0.26in)]
Lower rail.....Fixed on seat stand.
[Forward 60mm (0.19in), backward 60mm (0.19in)]
Amount of adjustment of seat height
[Up; 23mm (0.07in), down; 37mm (0.16in)]
Suspension stroke
[Up; 37.5mm (1.48in), down; 37.5mm (1.48in)]
33-4
33.1.2 CAB
33.1.2.1 REMOVAL 33
(1) Remove floor mat.
(2) Remove cover assy (A8).
1.
Remove 3 caps (A15) and loosen 4 sems
bolts (A38) M6X20.
Tools: Phillips screwdrive
2.
Disconnect harness connector of power
socket and remove cover assy (A8).
(3) Removal of cover assy (A10).
1.
Loosen 2 sems bolts (A38) M6X20.
Tools: Phillips screwdriver
2.
Remove cover assy (A10).
(4) Removal of harness connector.
(See Chapter 23 "Electric System")
1.
Disconnect connectors of cab harness at
Disassembly and assembly of right panels
rear right of cab.
(A1), (A8) and (A10)
2.
Disconnect antenna cable for tuner located
at rear left of cab.
3.
Disconnect harness for cab light located at
rear left of cab.
(5) Removal of cover assy (A1).
1.
Loosen 2 sems bolts (A38) M6X20.
Tools: Phillips screwdriver
2.
Disconnect harness connector of hour-meter
and remove cover assy (A1).
(6) Remove plastic tube for window washer
located at right front of cab.
33-5
(7) Removal of mechatro-controller

1.
Loosen 4 sems bolts (B9) M6X25.
2.
With harnesses are connected condition,
remove mechatro-controller, and place it in
front of it temporally.
Removal of mechatro-controller
(8) Removal of cab attaching bolts

1.
Loosen 4 capscrews (C1) M12X35.
2.
Loosen 2 nut (D4) M16.
3.
Loosen 2 nut (D9) M20.
Removing and installing cab mounting bolts
Removing and installing cab mounting bolts
33-6
(9) Slinging cab

1.
Remove 2 plastic plugs at the front of the
33
ceiling of the cab, and attach 2 eyebolts.
Then hook slinging wires to eyebolts as
shown in figure.
2.
Then lift up cab slowly avoiding interference
with surroundings.
Wire with hook;
Length 1.5m (4ft 11in) X Dia. 10mm
(0.4in) X 3pcs.
Weight of cab; Approx. 400kg (880lbs)
Slinging cab
33.1.2.2 Installation
Install it in reverse order of removing according to the Tightening Torque Table.
33-7
33.1.3 BATTERY
33.1.3.1 REMOVING
(1) Open left hand cover (1).
1. Open it with starter key.
2. Open left hand cover (1).
3. Fix it with stay.
(2) Remove battery cover (A1)
Loosen 3 sems bolts (A6) M8 and remove
battery cover (A1).
(3) Remove battery cable
1.
Remove cable (4) [between the earth and
battery (-)].
(Always remove (-) terminal first and install
it at last.)
2.
Remove cable (5) [between battery (+) and
(-)]
3.
Grounding cable for main body
Remove cable (3) [between battery (+)
and battery relay]
Follow the battery removal order.

Start removing battery from grounding side, and finish attaching to grounding side. If this order is
missed, short-circuits may occur.
(4) Remove battery (B1)

1.
Loosen 2 capscrews (A3) M10X225.
Tools: Socket: 17mm
2.
Remove plate (A2).
3.
Remove battery (B1).
Removing and installing battery cable
33-8
33.1.3.2 INSTALL
(1) Install the battery in the reverse order of removing.
Hold down plate (A2) against battery (B1), and tighten capscrew (A3).
33
Tools: Socket: 17mm
Tightening torque : 10.8N-m (8.0 lbf-ft)
(2) Installing grounding cable
Install grounding cable (4) last. Especially care must be taken that the grounding face is free
from painting, rust, etc.
33-9
33.1.4 GUARD
33.1.4.1 PREPARATION FOR REMOVAL
(1) Remove guard in the following procedure.
Remove these equipments according to
the order of items (2), (4), (3), (5), and (1).
(2) All the locked equipment, open them using
starter key.
Guard assy
33.1.4.2 REMOVE GUARD

(1) Remove panel assy (2-1)
1. Unlock panel assy (2-1) and open it.
2. Remove 2 sems-bolts M12X25.
3. Remove panel assy (2-1).
Tools: Socket: 19mm
Weight : 13kg (29 lbs)
Removing cover assy (2-1)
(2) Removing cover assy (2-5)

1. Remove 2 sems-bolts (2-2) M12X25
and 2 sems-bolts (2-13) M12 X 30.
2. Removing cover assy (2-5).
Tools: Socket: 19mm
Removing cover assy (2-5)

1. Remove 3 sems-bolts (2-2) M12 X 25.
Tools: Socket: 19mm
Removing panel assy (2-4)
33-10

1. Remove 2 sems-bolts (2-8) M12X40.
2. Remove a sems-bolt (2-18) M12X45.
33
Tools: Socket: 19mm
Weight : 14 kg (31 lbs)
Removing panel assy (2-3)
(5) Remove cover assy (4-2)

2. Remove cover assy (4-2).
Tools: Socket: 19mm
(6) Remove cover assy (4-1)
Tools: Socket: 19mm
Removing cover assy (4-1), (4-2)
(7) Remove bonnet assy (3-2)

1. Unlock bonnet assy (3-2) and open it.
3. Remove bonnet assy (3-2).
Tools: Socket: 19mm
Removing bonnet assy (3-2)
33-11
(8) Remove bonnet assy (3-1)

2. Remove bonnet assy (3-1).
Tools: Socket: 19mm
(9) Remove covers (3-3), (3-4)
4. Remove cover (4).
Removing bonnet assy (3-1) and covers (3-3),
Tools: Socket: 19mm
(3-4)
Weight : 10 kg, 4 kg (22 lbs, 9 lbs)
(10) Remove left hand cover (5-1)

1.
Open cover assemblies (5-1) and remove
the couplers from harness (1) for swing
flasher.
2.
Remove 2 sems-bolts (5-4) M12X25 and
remove left hand cover (5-1).
Tools: Socket: 19mm
(11) Remove right hand cover (5-2)
1.
Open cover assemblies (5-2) and remove
the couplers from harness (2) for swing
flasher.
2.
remove right hand cover (5-2).
Tools: Socket: 19mm
Removing left/right hand covers (5-1), (5-2)
(12) Remove bracket (1-5)

remove bracket (1-5).
Tools: Socket: 19mm
Removing bracket (1-5)
33-12
(13) Remove guard assy (1-2)

2.
33
Remove the sems-bolt (1-8) M12X25
attaching support (1-3).
3. Remove guard assy (1-2).
Tools: Socket: 19mm
(14) Remove pillar (1-4)
2. Remove pillar (1-4).
Tools: Socket: 19mm
Removing guard assy (1-2) and pillar (1-4)
(15) Remove guard assy (1-1)

2. Remove guard assy (1-1).
Tools: Socket: 19mm
Removing guard assy (1-1)
(1) Installing is done in the reverse order of removing.
(2) Tightening torque
Tools: Socket: 19mm, M12 79.4 N-m (58.6 lbf-ft)
33-13
33.1.5 UNDER COVER

33.1.5.1 REMOVAL
(1) Remove under cover (1,2,3,4,5,6)
1. Remove sems bolts (7) M12X30.
2. Remove covers.
Tools: Socket: 19mm
Removing under cover assy
(1) Install under cover (1,2,3,4,5,6)
Tools: Socket: 19mm
33-14
33.1.6 FUEL TANK

33.1.6.1 PREPARATION FOR REMOVAL 33
(1) Draining fuel (See Fig. "Removing fuel
tank")
1. Unlock cap (B1) with a starter key and
open it.
2. Loosen valve (A10) under the tank.
3. Draining fuel
Capacity of tank : 367L (97gal)
(2) Remove panel assy (2-3),(2-4).
(See 33.1.4 GUARD)
(3) Remove the connector for fuel level sensor
(A4).
(See Fig. "Removing fuel tank")
(4) Remove fuel hose
1.
Loosen clip (17),(18) and draw out hoses
(8) and (9).
2. Put in plugs that match the hose bore. Removing fuel hose (8),(9)
33.1.6.2 REMOVAL
(1) Remove 4 capscrews (A1) M16X50.
Tools: Socket: 24mm
(2) Hook the wire to the lifting eye on the
fuel tank assy (B6) and remove the fuel
tank.
(3) Remove shim (A3).
Removing fuel tank
Record the shim locations.
33-15
Tank attaching bolt (A1) M16X50
Tools: Socket: 24 mm, Apply Loctite #262
Tightening torque: 191N-m (140 lbf-ft)
If the gap (looseness) between tank mount and frame exceeds 1 mm (0.04 inch), adjust the gap with
shim (A3) and tighten capscrew (A1) to install the tank.
33-16
33.1.7 HYDRAULIC TANK

(1) Swinging upper structure 45 degrees.
Swing upper structure to make the
removal of suction hose for pump installed
under tank easier.
(2) Necessary to remove the hydraulic oil tank.
Swinging upper structure 45 degrees
(3) Bleeding internal air of tank

Press cap by finger to bleed internal air.
Bleeding internal air of tank
Keep pressing until the hissing sound stops.
(4) Remove cover (B1)

1. Remove 6 sems bolts (B10) M10X25.
Tools: Socket: 17mm
2. Remove cover (B1).
3. Remove suction strainer (B4).
(5) Remove cover (B2)
1. Remove 6 sems bolts (B10) M10X25.
Tools: Socket: 17mm
2. Remove cover (B2).
3. Remove filter element (B7).
(6) Turn the handle of element assy (B7), and
disassemble the removed filter element (B7).
(7) Draining hydraulic oil
Place pump in tank and draw up hydraulic
oil.
Capacity of tank : 72 L (19gal)
Remove cover (B1),(B2)
33-17
33.1.7.2 REMOVAL
(1) Draw out the suction hose (1)
Remove 2 clips (9) of the tank side and
pull out hose (1).
Tools: Flat-blade screwdriver
Removing the suction hose
(2) Disconnecting the main pipe return hose (7)

(3) Remove drain hose (6) of pump
(4) Remove drain hose (4) of swing motor
Removing main piping return hose
(5) Disconnecting pilot return hose
1. Remove pilot hose (A1),(A22).

2. Remove pilot hose (A4).
3. Remove pilot hose (A6).
Remove pilot return hose
(6) Remove drain hose (6) of pilot pump

Removing pump drain hose
33-18
(7) Remove hydraulic tank attaching bolt

Remove 4 capscrews (A1) M16X50.
Tools: Socket: 24mm
33
(8) Slinging hydraulic oil tank
Place a wire sling, using the lifting plate on
top of the tank.
Tank weight: Approx : 62kg (137 lbs)
(9) Remove shim (A3).
Removing hydraulic tank
Record the shim locations.
33-19
(1) Cleaning hydraulic oil tank
(2) Cleaning suction hose
(3) Cleaning mount of tank.
Installing is done in the reverse order of removing.
(4) Install 4 mounting capscrews (A1) M16X50 with Loctite #262. (See Fig. "Removing hydraulic tank".)
Tools: Socket: 24mm, Apply Loctite # 262
If the gap (looseness) between tank mount and frame exceeds 1mm (0.04 inch), adjust the gap with
shim (A3) and tighten capscrew (A1) to install the tank.
(5) Connection of suction hose

(See 33.1.8.2)
1.
Apply PERMATEX on pipe side of hose
connection and insert it.
2.
Put the hose with clip (A19).
Tightening torque: 5.39N-m (4.0 lbf-ft)
(6) Assembling return element
Assemble filter element by the use of
element kit. (See right Fig.)
(7) Install return element. (See Fig. "Remove
cover (B1), (B2)")
(8) Installing suction strainer (B4)
(9) Tighten sems bolts (B10) M10X25 that
attach tank covers (B1), (B2). Return element & suction strainer
M10 Tightening torque : 46.1 N-m (34
lbf-ft)
Two elements (B7-1) are used as one set.
Replace O-ring fitted on the back side of tank cover with new one.
33-20
33.1.8 HYDRAULIC PUMP

(1) Remove bonnet assy (3-1),(3-2).
(See 33.1.4 GUARD (7),(8))
(2) Remove cover assy (3-3),(3-4).
(See 33.1.4 GUARD (9))
(3) Remove counterweight.
(4) Release pressure in hydraulic oil tank.
(See 33.1.7 HYDRAULIC TANK)
(5) Remove 6 capscrews (B10) M10.
(6) Remove cover (B1).
Tools: Socket: 17mm
(7) Take out suction strainer.
(8) Install suction stopper.
For suction stopper, see Chapter "Tools".
Hydraulic oil tank
Pump can be removed even when counterweight is not removed. But removal of counterweight
facilitates working, and the working time is also reduced.
(9) Disconnect drain down pipe installed under engine muffler.
33.1.8.2 REMOVAL
(1) Loosen sems bolts (13) M12X40 and
remove half clamp (7). And disconnect 2
hoses (17), (A5) from the delivery side.
(See right Fig., and Fig. "Pump port")
(2) Remove suction flange
1. Remove 4 socket bolts (14) M12.
2. Remove flange (3) of suction hose (1)
from pump (S1).
Tools: Allen wrench: 10mm
33-21
(3) Removing other hoses
1. Disconnect hoses of the following ports.

2. Attach tags to hoses to identify.
Pump port
(4) Removing main pump

1. Attach eye bolt (M10) on upper surface
of pump.
2. Lift it with wire lightly.
3. Remove 2 socket bolts (4) M12.
4. Pull pump horizontally and remove it.
Weight of pump : Approx. 45 kg (99 lbs)
Removing pump
33-22
Installing pump in the reverse procedure of removal following the specification for tightening torque and
sealant.
33
(1) Apply grease on spline of input shaft.
Grease ; Shell Retinax AM
(General-purpose extreme-pressure
molybdenum disulfide grease)
(2) Hook wire to eye bolts (M10) on upper
surface of pump and lift it.
(3) Insert pump spline section.
Installing pump
(4) Remove suction stopper

(5) Mounting suction strainer
(6) To bleed air by loosen the air vent port.
(7) Check hydraulic oil level.
(8) Start engine and check it for oil leakage
and noise.
(9) Install guards
See 33.1.4.2 (7),(8),(9).
Release air in pump
After replacing pump, be sure to fill hydraulic oil of 1L (0.26 gal) or more.
33-23
33.1.9 AIR CLEANER

(1) Opening bonnet assy (2)
1. Unlock it with starter key.
2. Open bonnet (2) and support it with stay
(5).
(2) Unplug terminals on indicator lines (5-5)
(See Fig. "Pulling out hose (3)")
Preparation for removal
33.1.9.2 REMOVAL
(1) Pulling out hose (5).
1. Loosen clips (11) on air cleaner side.
2. Pulling out hose (5)
Tools: Flat-blade screw driver
Pulling out hose (5)
(2) Pulling out hose (3)

1. Loosen clip (11) on air cleaner side.
2. Pulling out hose (3).
Tools: Flat-blade screw driver
(3) Remove air cleaner assy (1)
1. Remove 2 sems-bolts (7) M8X16.
2. Remove air cleaner assy (1) together
with bracket (2).
Tools: Socket: 13mm
Pulling out hose (3)
33-24
(1) Installing is done in the reverse order of
removing.
33
(2) Spare parts for deteriorated elements
33-25
33.1.10 MUFFLER
(1) Remove 4 sems-bolts (9).
(2) Remove exhaust tube (3),(4).
(3) Remove guard (3).
(4) Remove right hand cover (2).
33.1.10.2 REMOVAL
(1) Remove U bolt (6).
1. Remove 4 nuts (14) M8.
Tools: Socket: 13mm
2. Remove 2 U bolts (6).
(2) Remove cover (18).
1. Remove 3 sems-bolts (21),(22).
2. Remove 2 capscrews (23).
(3) Remove clamp assy (5)
1. Remove 2 capscrews (9) M10X35
Tools: Socket: 17mm
2. Separate clamp assy (5) from muffler (1).
(4) Removing other parts
Remove brackets (2) as necessary.
Tools: Socket: 19mm Removing exhaust tube (3)
Removing and installing the muffler
33-26
Installing is the reverse order of removing with attention paid to the following items:
33
(1) Procedure of fastening U bolt (6) (See right
Fig.)
1.
Tighten 4 nuts (A) till there is no space
and make sure that the dimension C is
even all around.
2.
Tighten nuts (A) to specified torque and
confirm the C dimensions on the right and
left once again.
3.
Tighten nuts (B) to specified torque and
make sure that U bolts are not inclined.
Nut A : 8.8 N-m (6.5 lbf-ft)
Nut B : 10.8 N-m (8.0 lbf-ft)
(2) Installing clamp assy (5)
1.
Place the end of clamp (5) 10mm (0.40in)
away from the tip of the muffler slit so the
joint of clamp does not extend over the
slit in the muffler. (See right Fig.)
2.
Install the clamp assy (5) in the illustrated
direction.
(3) Install cover (18).
1. Tightening torque :
Sems-bolt (21) : 9.8 N-m (7.2 lbf-ft)
Sems-bolt (22) : 29.4 N-m (21.7 lbf-ft)
Capscrew (23) : 9.8 N-m (7.2 lbf-ft)
Installing the muffler
(4) Replacing parts
33-27
33.1.11 COUNTERWEIGHT
(1) Removing bonnet assy (3-2).
Remove bonnet on engine. (See 33.1.4.2(7))
(2) Removing bonnet assy (3-1). (33.1.4.2(8))
(3) Preparing slinging jig
Remove plug (A6), and attach weight
slinging jig (See Chapter Tools.) to
counterweight.
Lifting up counterweight
33.1.11.2 REMOVAL
(1) Lifting up counterweight temporarily
Hook wire rope to slinging jig, and lift it
and stretch wire rope to the degree where
it is providing no slack temporarily.
Weight of counterweight : Approx. 840 kg
(1850 lbs)
Wire more than ø10 (0.394") : 1.5 m (4 ft
11 in) X 2 pcs.
(2) Removing counterweight
1. Remove 3 capscrews (A1) M20X130.
Tools: Socket: 30mm
2. Remove shim.
Removing counterweight
(1) Install counterweight in the reverse
procedure of removing.
(2) Install shim as it was
(3) Slinging counterweight
Check that 3 attaching bolts can be
screwed in by hand.
(4) Apply Loctite #262 on capscrews (A1),
and tighten them with washers (A2).
Tools: Socket: 30mm
(5) Remove slinging tools, and attach plugs
Attaching bolts counterweight
(A6).
33-28
33.1.12 RADIATOR & OIL COOLER

(1) Remove counterweight.
(2) Bleed air from the hydraulic tank and install
the suction stopper. (See 33.1.12
RADIATOR & OIL COOLER)
(3) Remove cover of suction strainer, and
adjust oil quantity so that oil level
becomes lower than the return tube level.
(4) Remove air cleaner hose
Refer to 33.1.9 AIR CLEANER
1. Loosen 2 clips (11).
2. Pulling out hose (5).
Removing hose (5)
(5) Removing under cover installed on lower

side of radiator.
Tools: Socket: 19mm
Removing under cover (3)
(6) Drain down of radiator

Put container 18L (4.8gal) under drain valve
hose for draining water.
[Water capacity of radiator : 4.6L (1.2gal)]
(7) Remove hose from radiator sub tank (6).
1.
Remove clip of radiator cap side and
disconnect hose (17).
3. Remove radiator sub tank (6) and guard
(5). Removing hose of sub tank (1)
Tools: Socket: 13mm
Do not loosen the joints of the hoses related to the air-conditioner. Otherwise the refrigerant leaks.
33-29
(8) Move air-conditioner condenser and receiver

tank
1.
Loosen 4 sems-bolts (60) M8X16 and
Loosen 2 sems bolts (8) M8X20.
Tools: Socket: 13mm
2.
Move a set of air-conditioner condenser and
receiver tank.
Moving condensers and receiver tank
33.1.12.2 REMOVAL
(1) Remove radiator stay (B1).
1. Remove 2 sems-bolts (B2) M12X30.
2. Remove 2 stays (B1).
(2) Remove water hose (11), (12).
1.
Loosen the hose bands (22), (24) for
water hose (11).
2. Remove hose (2).
3.
Loosen hose bands (22), (24) on water
hose (12) and remove a sems-bolt (25)
M10X25.
4. Remove hose (12).
Removing radiator assy
(3) Remove hoses (14), (15) for inter-cooler.

1. Loosen hose band (24) and remove
hose (15).
2. Loosen hose bands (23), (24) and
remove hose (14).
3. Remove two fixing U-bolts (19) from tube
(16).
4. Loosen sems-bolt (28) M8X20.
5. Loosen hose bands (22) and remove
hose (13) and tube (16).
Tools: Flat-blade screwdriver Removing and installing bracket assy (3) and
guard (1)
33-30
(4) Remove bracket assy (3)

2. Remove bracket assy (3).
33
(5) Remove guard (1)
2. Remove guard (1).
(6) Disconnecting hydraulic oil hose (2), (3)

1.
Loosen 2 capscrews (28) M10X50 for
attaching clamp (24), (25).
2.
Place an oil pan under the hose joint.
3.
Remove connector (15) and disconnect
"OUT" side tube (2) and hose (8).
4.
Remove elbow (20 and disconnect "IN" side
hose (3).
(7) Remove radiator assy. (See Fig.
"Removing radiator assy")
1. Remove 4 sems bolts (A2) M12X30.
Removing hydraulic oil hose (2), (3)
Tools: Socket: 19mm
2.
When lifting the engine fan, shift the
radiator so it does not interfere with the
engine fan.
3. Plug up pipe ends with clean cloth, etc.
4. Removing radiator
Place a wire sling in the lifting eyes of the
radiator assy and remove the assy by
crane.
33-31
removing. And removed clips of hose
should be clamped at original position.
(2) Install radiator assy
Place a wire sling in the lifting eyes of the
radiator and move it to original position
temporally. And install hydraulic hose,
radiator hose and hose of inter-cooler.
Regarding Inserting width of hose. (See
right Fig.)
(3) Radiator attaching bolt
Apply Loctite #262 on 4 semsbolts (A2)
M12X30.
Tools: Socket: 19mm
Inserting width of hose
(4) Adjust the clearance between the fan and
the radiator shroud all around the
circumference, as below :
Full circumference:
20±5mm (0.8in±0.2in)
(5) Clean the plastering area of the insulation
thoroughly before plastering it.
(6) Making up hydraulic oil and LLC (Long Life
Coolant)
After completion of other installation, make
Back-and-forth adjusting position of radiator
up hydraulic oil and water.
Coolant volume of engine body : 2.8 L
(0.7gal)
Coolant capacity of radiator : 4.0 L (1.1gal)
Hydraulic oil capacity of oil cooler : 4.1 L
(1.1gal)
33-32
33.1.12.4 PROCEDURE OF DISASSEMBLING AND ASSEMBLING THE RADIATOR/INTER COOLER

CORE
(1) Preparation for disassembly and assembly 33
1. Remove one under cover at the bottom of
the radiator.
2. Wait till the engine coolant cools down so
you do not get burned. Then remove the
cap of the radiator, discharge the coolant
by opening the drain valve located at the
back bottom and receive it in a container.
* In case of removing inter cooler only,
the above mentioned work is not necessary.
Removing radiator and inter-cooler
(2) Disassembly
1. Loosen 8 sems bolts (A21) M8X16 attaching shroud assy (A5), remove shroud assy (A5).
2. Loosen 2 bolts (A17) attaching radiator core.
3. After confirming that the coolant has been drained out completely, loosen and remove only the
radiator side of hose bands (24) at the top and bottom of the radiator. (See 33.1.12.2 Fig.
"Removing radiator assy")
4. Lift and remove radiator core using lifting eyes and hoist on the radiator core.
Weight : approx. 4.8 kg (11 lbs)
Confirm the missing of rubber bushing (A16) under the radiator core.
5. Loosen a bolt (A17) attaching the top of the inter-cooler core.
6. Loosen and remove only the inter-cooler side of hose bands (24) at the top and bottom of the
inter-cooler. (See 33.1.12.2 Fig. "Removing radiator assy")
7. Lift and remove inter-cooler using lifting eyes and hoist on the inter-cooler.
Confirm the missing of rubber bushing (A16) under the inter-cooler.
8. Disconnection of oil cooler hose
Disconnect hose (2), (3) from upper and lower of cooler, and drain hydraulic oil. (See 33.1.12.2
Fig. "Removing hydraulic oil hose (2), (3)")
9. Lift cooler temporally using cooler head flange for slinging.
10. Loosen 4 sems-bolts (A22) M10X25 attaching oil cooler.
11. Lift the oil cooler.
There is no predetermined sequential order in removing radiator core, inter-cooler core and oil cooler.
Removing these components can be done as necessary.
(3) Installing
33-33
33.1.13 ENGINE
33.1.13.1 PREPARATION FOR REMOVING
(1) Remove battery ground (See 33.1.3 BATTERY)
(2) Remove bonnet and guard (See 33.1.4 GUARD ) Remove under cover (See 33.1.5 UNDER
COVER)
(3) Remove air cleaner hose (See 33.1.9 AIR CLEANER)
(4) Remove counterweight (See 33.1.11 COUNTERWEIGHT)
(5) Remove radiator hose and inter-cooler hose (See 33.1.12 RADIATOR & OIL COOLER)
(6) Remove fuel hose and heater hose, and if necessary disconnect air-con hose.
(7) If necessary, remove pump, muffler and radiator.
(8) Remove harness connector (Refer to ELECTRIC SYSTEM)
1. Remove E/G ground cable
2. Starter cable-Starter B terminal
3. Upper harness
Prepare a stand, which withstands the weight of the engine assy and can place the removed engine
firmly. (Refer to Tools)
Outside view of engine
33-34
33.1.13.2 REMOVAL
33
Dismantling and mounting engine
(1) Remove hose of engine oil filter

Place oil pan under the connection of filter (1), and disconnect 2 hoses (11).
(2) Plug connector of filter side and hose
(3) Loosen engine mounting bolt of frame
1. Loosen 2 nuts (20) M12.

Tools: Socket: 19mm
2. Loosen 4 capscrews (6) M12X120.
3. Remove 4 plates (5).
4. Remove upper rubber mounts (3) 2 each.
(4) Slinging engine body
Prepare a stand, which withstands the weight of the engine assy and can place the removed engine
firmly. (Refer to "Tool".)
1. Sling engine hooking wire to lifting lugs on the front and rear sides.
Weight: Approx. 200kg (441lbs)
Wire: 6 dia. (0.236 in) X 1 m (3 ft 3 in) - 2 pcs.
33-35
(5) Position engine on the stand stably.
33-36
33.1.14 CONSOLE COVER

33.1.14.1 REMOVAL 33
(1) Removing right-hand console cover
1. Press into the "A" part of rubber boot
which is tucked into console, and remove
right rubber boot (3-4) from console.
2. Loosen 2 sems bolts (7-9) M6X16.
Tools: Plus screw driver
3. During lifting right upper console cover
(7-1A) up; disconnect connector of tuner
and antenna. Move boot (3-4) upwards
and remove console cover (7-1A).
-Removing of boot and lever is
unnecessary.
4. Loosen 3 sems bolts (1-16) M6X16 and
Removing boot (4)
remove lower console (1-3A).
(2) Removing left-hand console cover

1. Remove left boot (3-4) same way as right
console cover. (See above Fig.)
2. Loosen 2 sems bolts (1-16) M6X16.
3. Remove the left upper console cover (1-4A)
in the same way as right-hand console
cover.
4. Loosen 2 sems bolts (1-16) M6X16 while
lifting left under console cover (1-5A) up,
and remove left lower console cover.
Removing console covers
33-37
Install it in reverse order of removing according to the tightening torque table.
Removing left armrest
33-38

33.1.15.1 PREPARATION FOR REMOVING 33
(1) Remove panel assy (2-1) (See 33.1.4.2 Fig. "Removing cover assy (2-1)")
(2) Remove cover assy (2-5) (See 33.1.4.2 Fig. "Removing panel assy (2-4)")
(3) Release air in hydraulic oil tank, open cover of suction element of hydraulic oil, and lower the
level. (See 33.1.8.1 Fig. "Hydraulic oil tank")
Mark each hose with a port name before removing it.
33.1.15.2 REMOVAL
(1) Removing hoses for each piping
Attach tag on hose, and write port name on it, then remove hoses.
33-39
(2) Remove control valve

1. Remove 2 sems bolts (6) M12x30 and
remove 2 sems bolts (7) M12x35 attaching
bracket (1), remove bracket (1).
2. Remove 4 sems bolts (7) M12X35 from
upper frame.
3. Install the eye bolt to the tap (a) M12 X
depth 25.
4. Remove bracket (1) together with control
valve.
5. Remove 3 sems bolts (7) M12X35 from
bracket.
Removing main control valve
(1) Installing is done in the reverse order of remove.
Tools: Socket: 19mm
Weight of seat stand :
121 N-m (89 lbf-ft) (Bracket to upper frame)
100 N-m (74 lbf-ft) (Bracket to control valve)
(2) Make certain that attachment moves normally in operation.
(3) Check oil level and that it is free from oil leakage.
33-40
33.1.16 PILOT VALVE (FOR ATT)

The removing procedure for right and left is the same, so the preparation for left side is described
here.
(1) Put attachment on ground, stop engine

and release pressure in tank.
(2) Remove left console cover (1-4A), (1-5A)
assy referring to Section 33.1.14CONSOLE
COVER.
(3) Disconnect harness connector for horn at *
position.
(4) Attach a tag to the hose to make assembly
work easier.
Installing and removing boot and lever part
33.1.16.2 REMOVAL
(1) Remove hoses from your side to far side in
order.
Tools: Spanner: 19mm, 22mm
(2) Move the boot (3-4) up and loosen nut
(3-3).
(See above Fig.)
(3) Turn and loosen lever (3-1B) tightened in
pilot valve, and remove lever assy in a set.
(See above Fig.)
(4) Remove 4 capscrews (A14) M6X25. (See
right Fig.)
(5) Remove pilot valve.
(6) Plug hose ends.
Plug PF1/4, PF3/8 Pilot valve connector
Pilot valve port position (from upper side)
33-41
Install it in the reverse order of removal and tighten it.
Tools: Allen wrench: 5mm T = 11.8N-m (11 lbf-ft) capscrew (A14)
See Fig. "Pilot valve connector".
Make sure the tightening torque for capscrews, because pilot valve is made of aluminum.
33-42
33.1.17 PILOT VALVE (FOR TRAVEL)

(1) Release pressure in hydraulic oil tank
(2) Remove under cover (See 33.1.5 UNDER COVER)
(3) Remove floor mat
33.1.17.2 REMOVAL
(1) Disconnect pre pressure sensors connectors
at two places from under floor harness.
(2) Remove two pressure sensors.
(3) Disconnect lead cable CA103 for travel 1,2
speed at two places from under floor
harness.
(4) Attach tag, and disconnect connectors and
hoses.
Tools: Spanner: 19mm (P port)
Tools: Spanner: 19mm (T port, 1~4 port)
(5) Plug hose ends
Plug PF1/4
(6) Remove four capscrews (7) M10
(7) Remove right and left levers.
(8) Remove four socket bolts (10) M10.
(9) Remove pilot valve lifting it upward.
(10) Stop up holes with blank plugs PF1/4, 3/8.
Install it in the reverse order of removal and
tighten it to the below tightening torque.
Tools: Spanner: 19 mm, 22 mm T=29 N-m (22
lbf-ft)
Tools: Allen wrench: 8 mm T=46 N-m (34 lbf-ft)
Tools: Socket: 17mm T=46 N-m (34 lbf-ft)
Pressure sensor
Tools: Spanner: 19 mm T=29 N-m (22 lbf-ft)
Installing and Removing pilot V
33-43

(1) Park machine on flat and solid ground and
put attachment and dozer on ground.
(2) Operate the switch on gauge cluster and
select the pressure release mode, and
then release the inner pressure in circuit by
operating control lever. (See HYDRAULIC
SYSTEM)
(3) Release internal pressure through bleeder
of hydraulic oil tank.
(4) Remove boom as necessary to make work
easier. (Refer to chapter of Attachment.)
(5) Remove cab if necessary to make work
easier. (Refer to Chapter of Upper
structure.)
(6) Remove cover under engine.
(7) Attach tag to hose.
Swing unit piping
33.1.18.2 REMOVAL
(1) Remove hose.
1.
Remove hose (5) from the connector in
the makeup port MU.
2.
Remove 2 hoses (4), (9) from the Tee in
the drain port Dr.
3.
Remove hose (3) from the elbow of the PG
port. (For swing parking brake)
4.
Remove 2 hoses (7) from the connectors of
the A, B port.
Put in plugs PF3/8, PF3/4, PF1/2, and
PF1/4 into the removed ports.
(2) Removing the swing unit
1.
Remove a sems bolt (6) M10X20 and
Installing swing motor unit
remove connector (11).
2. Remove 8 capscrews (1) M16X50.
Tools: Socket: 24mm
3.
Remove tee of MU port and install eye
bolts.
33-44
4.
Put a wire sling in the eye bolts and
remove the swing motor unit.
33
Weight of swing motor unit ;
Approx. 70kg (154 lbs) (Include reduction
assy)
33.1.18.3 PREPARATION FOR INSTALL

(1) Clean mating surfaces of swing motor unit and upper frame.
Tools : spatula, wash oil
(2) Apply Loctite #515 on entire mounting surface of swing motor unit.
Install the swing motor unit in the reverse order of disassembly, confirming the orientation of the
swing motor unit.
(1) Tighten 8 capscrews (1) M16X50.

Tools: Socket: 24mm
Tightening torque: 279N-m (206 lbf-ft) Apply Loctite #262
(2) Fill inside from motor drain port to casing with hydraulic oil before piping for drain
33.1.18.5 PREPARATION FOR DRIVE

(1) Before starting operation, check that gear oil #90 (API grade GL-4) level of swing reduction is
sufficient.
Amount of oil : 3L (0.8gal)
(2) When starting operation, operate motor in low idling and at low speed for several minutes, and
check it for possible oil leak and noise.
33-45
33.1.19 SWIVEL JOINT

(1) Remove attachment assy (Refer to 3. ATTACHMENT DIMENSIONS)
(2) Remove cab (See 33.1.2 CAB)
(3) Remove guard (See 33.1.4 GUARD)
(4) Removing hoses on undercarriage (See Chapter : Undercarriage)
(5) Remove swing reduction unit if necessary. (See 33.2.5 SWING MOTOR UNIT)
33.1.19.2 REMOVAL
(1) Remove travel motor hose and tube
1. Remove a hose (A1). (C port : PF1/2)
Tools: Spanner: 32mm, Tightening torque : 147N-m (108 lbf-ft)
2. Remove 3 hoses (A2). (A, B, D port : PF1/2)
3. Remove hoses (A4),(A6). (E port : PF3/8)
Tools: Spanner: 22mm, Tightening torque : 73.5N-m (54 lbf-ft)
4. Remove hoses (A3),(A5). (H port : PF1/4)
Tools: Spanner: 19mm, Tightening torque : 36.3N-m (27 lbf-ft)
5. Remove tubes (A9),(A10). (F, G port : PF3/8)
Removing piping (lower side)
33-46
(2) Disconnecting the hoses on the top part of swivel joint

1. Remove a drain hose (9). (E port : PF3/8)
33
Tightening torque: 73.5N-m (54 lbf-ft)
2. Remove hoses (7).
(B, C, D port : 1-142UN)
3. Remove a hose (6).
(A port : 1-14UN)
4. Remove hoses (1).
(F, G port)
Disconnecting the hoses on the top part of

swivel joint
(3) Remove whirl-stop of swivel joint.

1. Loosen the nut (3) M20.
2. Remove a capscrew (4) M20X85.
Removing whirl-stop nut & the capscrew
33-47
(4) Remove capscrew for installation

Attach eye bolt, lift it up temporarily, and
remove 3 capscrews (C2) M12X30.
Tools: Socket: 19mm
(See 11.7 SPECIAL TOOLS No.9 Plug)
Removing sems bolts for installation
(5) Slinging the swivel joint

Weight: Approx. 28kg (62 lbs)
removing.
Piping tightening torque
(2) Check for oil leak and the hydraulic oil
level.
(3) Check for operating.
33-48
33.1.20 UPPER FRAME

(1) Remove attachment (See chapter 32)
(2) Remove cab (See 33.1.2 CAB)
(3) Remove guard (See 33.1.4 GUARD)
(4) Remove counterweight (See 33.1.11 COUNTERWEIGHT)
(5) Remove swivel joint (See 33.1.19 SWIVEL JOINT)
33.1.20.2 REMOVAL
(1) Lifting up upper frame temporarily
Attach an upper-frame hoisting jig to
attaching holes of counterweight. Attach 2
chain blocks to holes of boom foot pin
and use these four points and hoist
upper-frame.
Wire ropes ;
16 dia. X 2.5m, 1pc.
16 dia. X 1.5m, 2pcs.
Chain blocks ; For 1 ton, 2pcs.
Lifting up upper frame temporarily
(2) Marking match marks on swing bearing

Put match marks on upper frame and
swing bearing.
Matching mark on swing bearing and upper

frame
(3) Removing upper frame attaching bolts

Remove 23 capscrews (B31) M16X85 and
a reamer bolt (B30) used to install swing
bearing and upper frame.
Tools: Socket: 24mm
(4) Slinging upper frame
Sling according to Fig "Lifting up upper
frame temporarily", and remove upper frame
and put it on a stand.
Weight: Approx. 5ton (11,000 lbs)
Removing upper frame attaching bolts
33-49
(2) Cleaning mating surfaces of upper frame and swing bearing.
(3) Apply Loctite #515 to the inside of the capscrews on the contact surface.
(4) Slinging upper frame
Match marks and install it with three reamer bolts temporarily.
Tools: Socket: 24mm Apply Loctite #262
Tightening torque : 157N-m (120 lbf-ft)
(5) Install swing bearing
Install 23 capscrews (B31) M16X85.
Tools: Socket: 24mm Apply Loctite #262
Install a reamer bolt (B30).
Tools: Socket: 24mm,
Bearing mount
Reamer bolt position (*) Apply Loctite to

shaded area
Confirm the reamer bolt positions referring to above Fig.
33-50
33
33-51
33.2.1 HYDRAULIC PUMP - REGULATOR

Construction of hydraulic pump & regulator
33-52

1 SHAFT 1 31 SPRING 1 61 ROD RE 1
2 OIL SEAL 1 32 SPRING GUIDE 1 62 SPRING 6 33
3 SHIM REC 33 CAP: PF1/16 6 63 PISTON RE 1
4 HOUSING 1 34 O-RING: A90 6 64 COVER 1
5 TAPERED ROLLER BRG. 1 35 ROD PW 1 65 SPRING 1
6 SCREW: M5X10 2 36 SLEEVE 1 66 BUSHING 2
7 CRADLE H 1 37 PIN 1 67 SPRING 2
8 CAM 1 38 SERVO CASE 1 68 PLUG 2
9 RETURN PLATE 1 39 ROD 1 69 O-RING: 1B P22.4 1
10 PISTON ASSY 9 40 PISTON B 1 70 CAP RE: PF3/4 1
11 CYLINDER 1 41 POWER PISTON LAS 1 71 COUPLING 1
12 PORT PLATE CW 1 42 PISTON 1 72 GEAR PUMP 1
13 RING 1 43 SPRING 1 73 SOCKET BOLT: M10X30 1
14 BUSHING 1 44 O-RING 1 74 SNAP RING 1
15 SPRING 1 45 SERVO COVER H 1 75 PLUG 1
16 CRADLE L 1 46 PISTON H 1 76 O-RING: P11 A90 3
17 RETAINER SPH 1 47 SERVO COVER 1 77 LINK 1
18 O-RING 1 48 PISTON U 1 78 PIN 1
19 PARALLEL PIN 6 49 SOCKET BOLT: M6X70 4 79 O-RING: G50 A90 1
20 NEEDLE BRG. 1 50 O-RING: 1B P10 1 80 SOCKET BOLT: M16X90 3
21 O-RING: 1B G55 1 51 BUCK UP RING 1 81 CAPSCREW: M8X25 2
22 NUT: M10 1 52 STOPPER 1 82 WASHER 2
23 NUT: M20 1 53 SET SCREW: M12X30 1 83 SOCKET BOLT: M16X110 1
24 O-RING: P9 A90 4 54 NUT: M12 1 84 CAP: PF1/4 2
25 CAP SP: PF1 1 55 CAP: PF1 1 85 CAP ASSY 1
26 O-RING: 1B P29 2 56 SPRING 1 86 SERVO CASE ASSY 1
27 SLEEVE 1 57 SEAL RETAINER 1
28 O-RING: 1B P20 1 58 SOCKET BOLT; M10X20 6
29 STOPPER 1 59 O-RING: 1B G75 1
30 SPRING 1 60 GUIDE 1
33-53
33.2.1.2 DISASSEMBLY AND ASSEMBLY

(1) Disassembly of components (Body, Regulator, Gear pump)
1. Gear pump removing
Loosen bolts (81) (Opposing flats 13), and
remove plain ground washers (82) and gear
pump (72).
Remove collar, coupling (71), and O-ring
(21).
Gear pump removing
2. Removing regulator
Loosen bolts (73) (Opposing flats 8), and
remove regulator. Remove pin (19) from
cover (64).
Removing regulator
The regulator might be hard to remove due to the interference of parallel pin (19).
33-54
(2) Piston pump disassembly

1. Disassembly of regulator
Turn the piston pump upside down and
33
face shaft input axis downwards, fix
housing (4) to work bench with bolts (M12
X 30). Loosen cap PW (55) (Opposing flats
41) and remove spring (56).
The cap PW (55) has stopper (52), set
screw (53), and nut (54). Loosen cap RE
(70) (Opposing flats 36) and remove
spring (65). Using magnet, remove piston
RE (63) and rod RE (61). Loosen socket
bolts (80) (83) (Opposing flats 14).
Disassembly of regulator
-Above mentioned cap is used to determine the maximum flow rate and the minimum flow rate. Make
sure to mark the original position with matchmark for reassembly before disassembly.
-Do not loosen nut (54) when not required.
-Since piston pump is turned upside down in the following procedure, loosen socket bolt but do not
remove it completely.
2. Removing seal retainer

face the input shaft axis upwards.
Loosen socket bolt (58) (Opposing flats 8)
and remove seal retainer (57), shim (3),
and O-ring (59).
Removing seal retainer (57)
Use the tapped hole (M10) provided on seal retainer (57).
33-55
3. Removing oil seal

Put seal retainer (57) on wood blocks (30
mm in height), and tap the oil seal (2)
with screw driver and remove it.
4. Removing bolts
Remove 3 socket bolts (80) and 1 socket
bolt (83) (Opposing flats 14) from cover
(64).
Removing oil seal (2) and bolts (80),(81)
Do not reuse oil seal (2).
5. Removing housing
Lift housing (4) by hand and remove it.
(About 10 kg)
Removing housing (4)
-During removing inner parts, do not damage them.

-The housing might be hard to remove due to the interference of parallel pin (19). At that time, tap the
housing flange using soft head hammer to make the removal easier.
33-56
6. Removing rotary assembly

Remove parts installed on cover (64) in
order of shaft (1) on which taper roller
33
bearing inner race (5) is installed, cam (8),
return plate (9) on which piston assembly is
installed, retainer SPI (17), spring (62),
cylinder (11), port plate CW (12), and
bushing (66). And then, remove rod PW
(35) and power piston assembly (41).
Removing rotary assembly
Put matchmark on the sides of return plate (9) and cylinder (11) to make the installation position into
piston hole easy to find.
7. Removing bushing
Remove O-ring (18), ring (13), bushing (14),
and spring (15) from cover (64).
Removing bushing (14)
33-57
8. Removing taper roller bearing

Apply gear puller to inner race of taper
roller bearing (5) and spline of shaft (1) as
shown in right Fig., and remove the inner
race of taper roller bearing (5) from the
shaft.
Removing taper roller bearing (5)
9. Removing cradles
Loosen socket head screws (6) (Opposing
flats 3) and remove cradles (7) (16). And
remove the outer race of taper roller
bearing (5).
Removing cradles (7), (16)
Cradles (7) and (16) differ from each other in groove form. Install them to the original positions by
putting the matchmark when assembling the cradles again.
33-58
(3) Disassembling regulator

1. Loosen and remove cap SP (25) (Opposing
flats 41) and remove springs (30) (31) and
33
spring retainer (32). Using a magnet,
remove rod (39) and piston B (40) together.
Loosen 4 socket head bolts (49), remove

regulator cover (47), piston U (48), and
O-ring (44). And then remove regulator
cover H (45), piston H (46), and O-ring
(44).
And remove piston (42) and spring (43).
Disassembly of regulator (1/2)
Do not loosen nut (23) when not required.

(It might change the power setting.)
2. Remove O-rings (24) (79) from regulator

casing (38).
Using a pliers, remove snap ring (74), and
using tapped hole (M5), remove plug (75).
Remove link (77) and then remove sleeve
(36).
Disassembly of regulator (2/2)
33-59
(4) Preparation for assembly

Complete the following items in advance before reassembly.
1. Check every part for possible damage

caused by operation or disassembly, and
when flaw found, remove the flaw with oil
stone in grain size or sand paper as
required, clean it with the wash oil and
dry it with air blow.
2. Replace all sealing parts with new ones.
(Oil seal and gasket included)
3. Lap the sliding surfaces of piston
Lapping of piston assembly
assembly (10), cylinder (11), port plate
(12) and cam (8) with #2000 sand paper
on surface plate.
4. In installing sealing parts, apply grease
slightly prior to assemble.
5. When assembling sliding section, apply
thin film of clean hydraulic oil before
assembling.
(5) Assembling of piston pump body

1. Installing of bushing
Install spring (15), bushing (14), and ring
(13) into cover (64) in order. And install
O-ring (18) into O-ring groove of cover (64).
Installing of bushing
Installing of O-ring (18)
33-60
2. Installing of port plate

Apply grease to bushing (66) to prevent
from fall. And install the bushing into the
33
hole of port plate (12). Then align the port
plate with positioning pin, and install it into
cover (64).
Installing of port plate (12)
Positioning of cover (64)
3. Installing of piston assembly

Install return plate (9), which is installed
spring (57), retainer SPH (17), and piston
assembly (10), into cylinder (11).
Installing of piston assembly (10)
Refer to matchmark, which is put on the side faces of return plate (9) and cylinder (11) prior to
disassemble it, install piston assembly (10) to the original hole.
4. Installing of cradles
Install cradles (7) (16) into housing (4), and
tighten them to the specified torque 5.9
Nom (4.4 lbfoft) with socket head screw
(6) (Opposing flats 3).
Installing of cradles (7), (16)
33-61
Tighten socket head screw (6) temporarily to position cradles (7) and (16) in parallel. And apply
hydraulic oil to cradles (7) and (16), place cam (8) on them, and get the smooth movement of
cradles by tilting several times. Then remove cam (8) once and tighten socket head screw (6) to
specified torque.
5. Installing shaft
Apply hydraulic oil to port plate (12) (sliding
surface with cylinder (11)) which is
installed by the procedure shown in Item
2). And place the port plate on cylinder
(11) which is installed by the procedure
shown in Item 3). Apply hydraulic oil to
the shoe sliding surface of piston
assembly (10) and place cam (8) on the
shoe sliding surface.
Install shaft (1) so as to connect to the
spline of cylinder (11).
Install power piston assembly (41) on
cover (64) and install rod PW (35) on
power piston assembly (41).
Installing shaft (1)
6. Installing rod PW
In order to make the assembly easier,
install spring (Jig) to the lower part of
power piston (41) and cover the spring with
cap (Jig) to float power piston (41).
Connect power piston assembly (41) and
cam (8) to rod PW (35) in this condition.
Installing rod PW (35)
-Apply grease on the spherical surface of rod PW (35).

(To prevent fall)
-Pay attention to rod PW (35) direction. The side the diameter of sphere is larger is in contact with
the cam.
33-62
7. Installing housing
Lower the housing assembly slowly which
is assembled by the procedure of Item 5)
33
from upper side of the cover assembly
which is assembled by the procedure of
Item 4). And tighten it temporarily with
socket bolts (80) (83) (Opposing flats 14).
Installing housing (4)
-In this case, cam (8) and cradles (7) (16) might be hard to fit each other. At that time, rock the
housing side assembly and it becomes easier to insert into cover assembly.
-Do not pinch your fingers between housing (4) and cover (64).
8. Installing taper roller bearing (Inner race)

Using press-fitting jig, and tap it with
hammer, and press-fit the taper roller
bearing (Inner race).
Installing taper roller bearing (Inner race) (5)
9. Installing taper roller bearing (Outer race)

Install taper roller bearing (5) (Outer race).
Installing taper roller bearing (Outer race) (5)
33-63
10. Installing oil seal

Clean and degrease the groove of seal
retainer (52) for oil seal (2). And clean the
periphery of oil seal (2) and apply liquid
sealant (ThreeBond #1211 or equivalent).
Then using assembly jig, install the oil
seal into seal retainer (52). Installing oil seal (2)
Pay attention to oil seal (2) installing direction.
11. Installing seal retainer

Install shim of the number of sheets which
was originally installed. Install seal retainer
(52) which is installed oil seal (2) and
O-ring (59) into housing (4). Remove seal
protector and tighten 6 socket bolts (58)
(Opposing flats 8) to the specified torque
64.7 N-m (47.7 lbf-ft).
Installing seal retainer (52)
-Apply grease to lip surface of oil seal (2) slightly.

-When adjustment of thickness with shim (3) is required after replacement of parts, refer to 33.2.1.2(8)
"Shim adjusting method".
12. Installing cap/rod RE/piston RE

Remove assembly jig (For cap and spring)
and install spring (56). And install cap (55)
(Opposing flats 41), which includes stopper
(52)/set screw (53)/nut (54).
Install rod RE (61) into piston RE (63)
and install them into cover together.
Installing of rod RE (61), piston RE (63)
33-64
33
-Remove the assembly jig using care that power piston assembly (41) is not moved toward cap (55)
side.
(Rod PW (35) may fall.)
-If rod PW (33) should fall, try the installation again from the procedure of Item 6.
13. Installing cap RE

Install assembly jig to cover (64) and push
piston RE (63) in. Remove assembly jig
and install cap RE (70) with spring (65)
and O-ring (69).
Installing cap RE (70)
14. Installing cap PW/cap RE/Tightening socket

bolt
face the input shaft axis downwards.
Install the pump to work bench with socket
bolts.
Tighten cap PW (55) (Opposing flats 41)
to the specified torque 350 N-m (258 lbf-ft).
Tighten cap RE (70) (Opposing flats 36)
Tighten 3 socket bolts (80) and a socket Installing cap PW (55), cap RE (70)
bolt (83) (Opposing flats 14) to the
specified torque 290 N-m (214 lbf-ft).
15. Check the assembling

After assembling the main pump, turn
shaft (1) with pipe wrench while protecting
spline shaft (1) with cloth, and make sure
that it rotates smoothly.
Check the assembling
33-65
(6) Assembling regulator

1. Install sleeve (36) to regulator (38) from
cap SP (25) side.
Installing of sleeve (36)
Install sleeve (36) placing the slotted hole in the depths.
2. Install link (77) on which pin (78) is

installed on the matching surface side to
cover (38), insert pin (78) into the slotted
hole of sleeve (36) and match the position
of link fulcrum hole of the regulator to that
of fulcrum hole of the link.
Install plug (75) with O-ring (76) is
Installing of link (77)
installed through the link fulcrum hole from
the side. Install snap ring with snap ring
pliers and install O-rings (24) (79).
Installing of plug (75) and O-rings (24),(79)
33-66
3. Install piston rod B (40) on rod (39) and

insert it in sleeve (36) installed by the
procedure shown in Item 2).
33
Install spring retainer (32), spring (31) and
spring (30) in order and tighten cap SP
(25) (Opposing flats 41) to the specified
torque 50 N-m (37 lbf-ft).
4. Install spring (43) and piston (42) on
regulator (38) in this order. Pass socket
bolt (49) through servo cover (47) on
which piston U (48) and O-ring (44) are
installed and servo cover H (45) on which
piston H (46) and O-ring (44) are installed,
bring the end face of servo cover H (45) in
contact with servo case (38), and tighten
socket bolt (49) to the specified torque 12
N-m (9 lbf-ft).
Assembling of regulator
-Be careful not to drop and miss piston B.

-Make sure that link moves smoothly.
-Pay attention to the directions of rod (39), piston B (40), piston (42), and piston H (46).
-Pay attention to the phases of servo covers (45) (47).
(7) Assembly of components

1. Assembly of control part
a. Using the hole of cover (64), install pin (37)

to power piston assembly (41).
Assembling of regulator
When the groove phase of power piston assembly (41) is displaced, turn it in circumferential direction
with scriber and adjust the groove phase of power piston assembly (41) to cover (64) pin hole.
33-67
b. Match the pin phase of power piston

assembly (41) to the notch of link (77),
install it on the main body so that the pin
falls in the range of helical groove, and
tighten socket bolt (73) (Opposing flats 8)
Position of pin phase
Checking on the link connection

A space about 3mm is left between servo case (38) and cover (64) due to the parallel pin (19) with
servo case (38) lightly placed on cover (64). Push link (77) with thin plate through this space and
check that it is not moved.
When it is wrong assembly, link (77) is moved.
2. Installing gear pump

Install O-ring (21) and collar to cover (64),
and assemble coupling (71) and shaft (1).
Then check the phase on gear pump (72),
and install it by tightening bolts (81)
(Opposing flats 13) with plain ground
washers (82) to the specified torque 32.4
N-m (23.9 lbf-ft).
If this pump does not have gear pump,
tighten bolts (81) (Opposing flats 13) with
hole caps to the specified torque 30 N-m
(22 lbf-ft).
Installing gear pump (72)
3. Check the assembling

After assembling the main pump, turn
shaft (1) with pipe wrench while protecting
spline shaft (1) with cloth, and make sure
that it rotates smoothly. And check the
rotation of gears in gear pump (72). Check the assembling
33-68
(8) Shim adjusting method

After disassembly and adjustment, if the shim
thickness adjustment is required by
33
replacement of parts, carry out the adjustment
by the following procedure. Prepare shim
adjusting collar 1, collar 2 for assembly jig in
advance, and install collar 2 on the outer ring
of taper roller bearing (5) and collar 1 on
housing (4) in the condition where the
procedure in Item 9) "Assembling piston pump
main body" is completed.
Place seal retainer (52) on it and tighten 3
socket bolts M10X35 to the specified torque 1.5
N-m (1.1 lbf-ft). Shim adjusting method
Measure the space between collar 1 and seal
retainer (52) with thickness gauge, and
determine
"Shim thickness = 1.9 - measured space value
(mm)".
Remove collars for adjustment and install shim
(3) equivalent to the determined thickness on
the outer ring of taper roller bearing (5).
(9) Assembly jig

1. Rod PW assembly jig
Spring
Spring rate : 0.3
Wire diameter : 1.4
Free length of spring : 60
Total number of coils : 5.25
Outer diameter : 17
Above mentioned specification spring or
equivalent is required.
2. Taper roller bearing press-fitting jig
33-69
3. Oil seal press-fitting jig
4. Assembly jig for seal retainer (Seal

protector)
5. Shim adjusting collar
33-70
6. Piston RE inserting jig
33
33-71
33.2.1.3 MAINTENANCE STANDARD

After disassembly of pump, if any remarkable damage was found on any part or the wear of each
sliding part is more than the standard value, replace the parts with new ones.
Inspection and
Standard
Parts Measurement Measuring Instrument Corrective action
(Service limit)
location
Roughness of shoe Surface roughness Correct by paper
0.8 S
sliding surface meter lapping
Flaw depth of shoe 0.4mm (0.016") or Replace with a new
Micrometer
sliding surface less one
Looseness of
Piston assembly (10)
connection part 0.4mm (0.016") or Replace with a new
Dial gauge
between caulked less one
piston and shoe
Outer diameter of
Hardly worn out. In case of flaw or seize, replace it with new one.
piston
Roughness of Surface roughness
Cam (8) 0.8 S Lapping
surface meter
Roughness of end Surface roughness
0.4 S Lapping
Cylinder (11) surface meter
Piston bore Hardly worn out. In case of flaw or seize, replace it with new one.
Roughness of Surface roughness
Port plate (12) 0.8 S Lapping
surface meter
Gap between
Micrometer
Piston assembly (10) piston outer 0.04mm (0.0016") or Replace with a new
Pneumatic
Cylinder (11) diameter and piston less one
Micrometer
bore
Parts Inspection and Maintenance Standard

If flaking on inner and outer race is found, replace the bearing with a new
Taper roller bearing (5)
one.
Needle bearing (20)
After disassembling replace the bearing with a new one, and reassemble it.
If flaw on lip is found, replace the oil seal with a new one.
Oil seal (2)
After disassembling replace the oil seal with a new one, and reassemble it.
O-ring If flaw on O-ring is found, replace the O-ring with a new one.
(18),(21),(26),(41),(43),(54),(64),(73) After disassembling replace the O-ring with a new one, and reassemble it.
33-72
Trouble Cause Remedy
Pump does not deliver. Pump does not run. Check connection of coupling. 33
Delivery rate is extremely small. Suction pipe and filter are clogged. Check pipe and clean suction filter.
Pressure does not rise.
Suction pipe is not immersed in Check hydraulic oil level.
hydraulic oil.
Wrong connection of regulator piping. Check piping for regulator.
Breakage of pump itself. Replace the damaged part.
Swash plate is not out of control. Correct failure.
Link and power piston were
assembled incorrectly.
Engine stalls. Set pressure of regulator is too high. Readjust set of regulator.
(Over load) Pump is seized or broken itself. Replace the damaged part.
Breakage of regulator itself. Replace the damaged part.
Oil leak Oil leaks from oil seal. Replace the oil seal with a new one.
Oil leaks from mating surfaces. If seal was damaged, replace it.
Check the tightening torque of
mounting bolts.
Check foreign matter between mating
surfaces.
Noise Air bubble is mixed in hydraulic oil. Check hydraulic oil level.
Abnormal vibration (Cavitation, Aeration) Check for the clogging of suction
pipe and filter.
Check suction pipe at air inlet.
Check viscosity of hydraulic oil.
Was the air bleed from casing done?
Pump is installed incorrectly. Align and readjust pump again.
Scuffing and seizure between piston Replace broken parts and check
and cylinder. cleanliness of hydraulic oil.
Seizure between cylinder and port Replace broken parts.
plate.
Wrong assembly of port plate. Check the assembling of suction and
delivery.
Abnormal wear of sliding parts. Replace worn parts.
Check cleanliness, moisture, viscosity,
and temperature of hydraulic oil.
33-73

33.2.2.1 PREPARATION FOR DISASSEMBLY
(1) General cautions
1. Since hydraulic components are finished to precision with small clearance, it is necessary to
disassemble and reassemble them in clean, less dusty place.
Use clean tools and cleaning oil and handle components with sufficient care.
2. If the control valve is removed from the machine, clean ports thoroughly and put a plug in each
port so as to prevent entry of dust and water.
When installing the control valve back to the machine, do not remove plugs until the valve is
properly piped.
3. Study the structural drawing before beginning work and prepare necessary parts according to the
purpose and the scope of the work. Some parts are not available loosely but in assemblies.
Therefore, prepare parts beforehand according to the Parts Manual.
(2) Cautions to be exercised in disassembly

1. Since components are finished to high precision, handle them with sufficient care. Use care so as
not to bump components against each other or drop them.
2. Do not strike or twist components by force even if they are tight, or the components develop burrs
or are broken. This makes the components impossible to be assembled and results in oil leakage
and deterioration in performances. Therefore, handle components with full care.
3. Attach a tag to each component so it is reassembled in a correct position.
4. Once disassembled, do not reuse O-rings and backup rings.
(Remove them with the tip of a steel wire shaped in a spatula. Take care so the groove is not
scored.)
5. If parts are left, as they are halfway during disassembly or after disassembly, they may rust due
to moisture and dust. When interrupting the work for unavoidable reason, use care so as to
prevent parts from rusting or being exposed to dust.
Replacing the main plungers

Since the main plunger is selectively fitted to the housing, it is designated as "not service part".
Therefore, note that in principle the main plunger cannot be replaced in the field. In case the plunger
must be replaced for some reason, inform us with the model and the manufacturing number that are
stamped on the nameplate.
33-74
(3) Tools and jigs

Holder
Matenrial: brass
33
Tools and jigs
Name plate
The disassembly procedure is explained as below. Assembly is the reverse order of disassembly.
Before disassembly, attach tags to parts so they are reassembled properly.
(1) Disassembling the main plunger

1. Remove socket bolt (1) and cover (2) in
that order.
Tightening torque : 13N-m (9.6 lbf-ft)
Removing cover (2)
Before reassembling the cover, make certain that an O-ring is placed on the mouth of the housing.
2. Draw out the plunger sub-assy.
Draw out the plunger sub-assy
33-75
-Do not draw out the plunger in a breath, but rotate it slowly while drawing it out and confirming the
contact with the housing.
-When reassembling BM-1, match the keyway at the tip of the plunger to the plug in whirl-stop cover.
3. Hold the plunger by the tool (holder), hold

it in a vise and loosen plunger cap (3).
Removing plunger cap (3)
Degrease the plunger and the holder thoroughly.
4. Remove plunger cap (3). Then remove

spacers (4) (5), spring (6), and spring guide
(7).
Removing plunger and spring
Note that the spring differs in each plunger.
(2) Removing main relief valve

1. Lock adjusting screw (1) and loosen nut (2).
2. Lock cap (4) and loosen cap (3).
Removing main relief valve
33-76
3. Loosen cap (4) and remove the cartridge

assembly.
33
4. Remove main poppet sub-assembly (A). Then remove orifice (5), spring (6), and main poppet (7)
from sleeve (8).
Removing sleeve (8)
5. Remove adjusting part sub-assembly (B).

Then remove spring (9) and pilot poppet
(10) from cap (4).
Do not disassemble pilot seat (C) because it is press fitted to the sleeve.
33-77
(3) Disassembling selector valve

1. Remove socket bolt (1) and remove
selector valve.
Tightening torqu : 30 N-m (22 lbf-ft)
Disassembling selector valve
Before reassembling the cover, make sure that an O-ring is placed in the mouth of the cover.
2. Remove snap ring (2), and remove spacer

(3) and rotor spool (4).
(4) Disassembling of load check valve

Remove cap (1), and remove spring (2) and
check valve (3).
Disassembling of load check valve
33-78
(5) Disassembling the load holding valve (Boom, Arm)

1. Disassembling the main poppet
33
a. Remove socket bolt (1) and cover assy
(2) in that order.
Load holding valve (Boom, Arm)
Before reassembling the cover, make sure that an O-ring is placed in the matching surface of the
cover.
b. Remove spring (3) and poppet (4).
Removing spring (3) and poppet (4)
33-79
2. Disassembling the cover (2)
a. Remove cap (5) and take out piston (6),

spring (7) and piston (8).
b. Remove cap (11), spring (10) and poppet
(8) in that order.
Disassembling the cover (2)
After a long period of operation, the poppet does not come off in some cases because of the edge on
the seat surface of sleeve. Do not disassemble it by force.
c. Remove cap (12) and remove spacer (13),

spring (14), and check valve (15).
d. Knock sleeve (9) out by lightly tapping it
to the left, using a pipe of ø4mm (0.157in)
bore diameter and ø10mm (0.394in) OD.
Removing sleeve (9)
33-80
(6) Disassembling of recirculation valve (Boom, Bucket)

1. Remove cap (1), and remove spring (2)
and check valve (3).
33
Disassembling of recirculation valve (Boom,

Bucket)
(7) Disassembling of pressure compensation valve (Dozer, Boom, Bucket)

1. Remove cap (1), and remove spool
assembly (2) and spring (3).
2. Hold spool assembly in the holder, hold it
further in a vise, and remove cap, spring
(6), and check valve (7).
Tightening torqu : 20 N-m (14.8 lbf-ft) Disassembling of pressure compensation
valve (Dozer, Boom, Bucket)
Degrease the plunger and the holder thoroughly.
33-81
3. Remove orifice cap (4) which was left in

the HG.
(8) Disassembling of flow control valve

1. Loosen cap (2) and remove it as an
assembly.
2. Remove cap (1), and remove spring
retainer (3), spring (4), spring retainer (5)
and spool (6). Disassembling of flow control valve
-When the cap (1) is removed, spring reacts with the force of 90 N (20.2 lbs) to 100 N (22.5 lbs).
Hold down the cap to prevent the parts jumping out, and remove every part.
-Do not disassemble the cap (8) because it was caulked.
33-82
(9) Disassembling of slow return check valve

1. Loosen cap (1) and remove filter retainer
(4) and filter (5).
33
Disassembling of slow return check valve
Direct the large rounded corner of the filter to the cap.
2. Remove orifice (2), and remove check valve

(3).
Tightening torque : 8 N-m (5.9 lbf-ft)
(10) Disassembling of arm recirculation valve

1. Loosen sleeve (1) and remove it as an
assembly.
Disassembling of arm recirculation valve
Do not disassemble sleeve (1) (8) because they are press fitted to seat (5).
33-83
(11) Disassembling of LS check valve

1. Loosen cap (1) and remove it as an
assembly.
2)
2. Remove cap (2), and remove spring (3),
and check valve (4).
Disassembling of LS check valve
(12) Disassembling of LS passage orifice

1. Loosen cap (1) and remove orifice
assembly (2). And then remove inner orifice
(3) from orifice assembly.
Cap
Orifice
Tightening torque : 1.5 N-m (1.1 lbf-ft)
Disassembling of LS passage orifice
-Do not disassemble filter because it was press fitted.

-Make sure of the orifice diameter because it differs according to the installed position.
33-84
(13) Disassembling of pressure compensation valve (Slewing, Travel, Arm)

1. Loosen cap (1) and remove spring (4) and
spool assembly (2). And then remove
33
inner orifice (3) from spool assembly.
Cap
Orifice
Disassembling of pressure compensation
valve (Slewing, Travel, Arm)
Make sure of the spring because it differs according to the installed position.
(14) Disassembling of over load relief valve
Do not disassemble the pressure adjusting part because it is difficult to adjust the pressure with the
real machine.
1. Loosen sleeve (1) and remove the over

load relief valve as a cartridge.
At body installing
Disassembling of over load relief valve
Install the over load relief valve to its original position because its setting pressure differs according to
the installed position.
33-85
2. Remove cap (2) as a sub-assembly and

remove spring (3) and pilot poppet (4).
Removing of cap (2)
3. Remove pilot seat (5), spring (6) (7),

piston (8), and main poppet (9).
(15) Addition of option valve

1. Loosen socket bolt and remove it.
Loosen socket bolts in order of D, C, B, and A.
33-86
2. Install optional addition valve and tighten

socket bolts.
33
-In this case, the total length of socket bolts is different depending on the kind and the number of
optional valve.
-Tighten socket bolts in order of A, B, C, and D.
-Be careful of over tightening of socket bolt, because the over tightening causes stick of main plunger.
33-87
33.2.2.3 ASSEMBLY
(1) Cautions to be exercised in assembly
1. Exercise care the same way as in disassembly.
2. Before proceeding to assembly, clean parts free from metallic particles and foreign matter and
make sure that the parts are free from burrs and dents. Eliminate burrs and dents with an oilstone
or the like.
3. Replace O-rings and backup rings with new ones.
4. Handle O-rings and backup rings with care so as not to score them.
(Apply a small amount of grease to make the surface smooth.)
5. Tighten bolts and caps to specified torque.
(2) Disassembly procedure

Assembly is the reverse order of disassembly.
33.2.2.4 PRESSURE SETTING OF MAIN RELIEF VALVE

(1) Assembly
1. Locate and confirm the set pressure "0"
position.
Direct the pressure adjusting sub-assembly
(B) downwards. And place spring (9) and
pilot poppet (10) on the sub-assembly (B).
Then cover the sub-assembly (B) with cap
(4) and assemble them.
And tighten the cap (4) temporarily until the
pilot poppet (10) comes in contact with the
seat of pilot seat (C) and the pressure
adjusting spring (9) begins to work.
2. Install main poppet sub-assembly (A) and
assemble it as a cartridge.
3. Assemble the temporarily assembled
cartridge to the valve body and tighten cap
(4).
4. Tighten the cap of pressure adjusting
sub-assembly (B).
Assembling of relief valve
If the pressure of the relief valve is not set properly, the hydraulic device may be destroyed in some
cases. This is dangerous. Therefore, do not raise the pressure above a level that is specified for
each machine model.
33-88
(2) Pressure setting

1. While monitoring the pressure gauge, turn
the adjusting screw (1) clockwise, and
33
adjust the pressure.
Pressure setting of relief valve
The pressure is changed about 8.5 MPa (1230 psi) per 1/4 turn.
Do not tighten the relief valve jerkily because this valve is extremely sensitive.
2. After the setting of pressure, lock the adjusting screw (1) and tighten nut (2).
Check the setting pressure by operating the plunger.
33-89
33.2.3 PILOT VALVE (FOR ATT)

33.2.3.1 CROSS-SECTIONAL VIEW
Pilot valve (For ATT)
Apply loctite #277 to areas marked ☆

101 Casing 1 *218-1 Seat 2
151 Plate 1 *218-2 Seat 2
201-1 Spool 2 221 Spring 4
201-2 Spool 2 241-1 Spring 2
211 Plug 4 241-2 Spring 2
212 Push rod 4 *246 Spring 4
213 Seal 4 47.1 (35) 301 Joint: M14 1
214 O-ring; 1B P20 4 302 Circular plate 1
216-1 Spring seat 2 68.6 (51)☆ 312 Adjust nut: M14 1
216-2 Spring seat 2 501 Boots 1
217 Washer 2 (Shim) 4
Note) The parts marked * might not be equipped depending on valve type.
33-90
(1) Plug each port of pilot valve, and clean it
with kerosine.
33
P port: PF1/4
1 to 4 and T port: PF3/8
(2) Fix pilot valve with vise via a protective
plate (Alminum plate etc.), and remove
boots (501).
Removing boot (501)
(3) Remove adjusting nut (312) applying

spanners to adjusting nut (312) and
circular plate (302).
Tools: Spanner: 22mm, 32mm
Removing adjusting nut (312)
33-91
(4) Remove circular plate (302)

Removing circular plate (302)
Circular plate is removed
Installing Jig A
(5) Turn joint (301) in counterclockwise with Jig

A to remove.
Jig A: See page 33.2.3.7(1).
Removing joint (301)
When the force of return springs (221) is strong, never loosen joint (301). If loosened, it might result in
jumping out of plate (151), plug (211) and push rod (212).
Remove joint (301) pressing plate (151) downward with two fingers.
33-92
(6) Remove plate (151)

-When the force of return springs (221)
are strong, press plate to let it come up
33
slowly.
Removing plate (151)
-When the force of return springs (221) are

weak, plug is left in casing (101) due to
sliding resistance of O-ring (214).
Tools: Pull plug (211) out with a driver.
Removing plug (211)
To prevent personal injury, plug (211) must be removed slowly and evenly until the return spring
(221) force is completely released.
(7) Remove push rod (212), plug (211),

pressure reducing valve assy (spool),
return springs (221) from casing (101).
Removing push rod, plug, pressure reducing

valve and spring
Record combination of port holes on casing and the pulled out parts. The stroke differs according to
direction.
33-93
(8) Push springs (241-1), (241-2) in the range

of 7mm (0.276in) that the movement of
spring seats (216-1), (216-2) and shift the
seats (216) in a side direction, and
remove spools (201-1), (201-2) through the
larger hole of seat.
Removing spool (201)
Never push down spring seat (216-1) in 7 mm (0.276 in) or more. (For port 1,3)
Never push down spring seat (216-2) in 9.4 mm (0.370 in) or more. (For port 2,4)
(9) Remove spool (201-1), (201-2), spring seats

(216-1), (216-2), spring (241-1), (241-2)
and washer (217).
Disassembling pressure reducing valve
(10) Remove spring (*246), spring seat

(*218-1), (*218-2) from push rod (212).
Disassembling push rod
The parts marked * might not be equipped depending on valve type.
33-94
(11) Pull out push rod (212) from plug (211).

(12) Remove O-ring (214) from plug (211).
33
Removing push rod (212)
(13) Remove inside seal (213) from plug (211)

with small driver.
Removing seal (213)
33.2.3.3 CLEANING PARTS

(1) Clean parts with wash oil roughly.
(2) Clean parts with wash oil completely.
(3) Dry parts by swabbing clean rag.
(4) Apply rust preventives on parts.
33.2.3.4 ASSEMBLING
(1) Fit washer 2 (217), springs (241-1), (241-2),
spring seats (216-1), (216-2) to spool
(201-1), (201-2).
Assembling pressure reducing valve
33-95
(2) Push spring (241-1), (241-2) in the range of

that the movement of spring seats (216-1),
(216-2) in a side direction, and install
spools (201-1) through the larger hole of
spring seat.
Installing spools (201-1), (201-2)
Never push down spring seat (216-1) in 7mm (0.276in) or more. (For port 1,3)
Never push down spring seat (216-2) in 9.4mm (0.370in) or more. (For port 2,4)
(3) Place spring (221) into ports 1,3 of casing

(101), and then install pressure reducing
valve assy in it.
Place springs (221) into ports 2,4 and
install it.
Installing pressure reducing valve assy
Install the removed respective assy into respective holes.
33-96
(4) Fit O-ring (214) and seal (213) into plug (211).
-Apply hydraulic oil on surface of push rod.
33
Installing O-ring (214) and seal (213)
(5) Insert push rod (212) in plug (211) and

install spring (*246) and spring seat
(*218-1) to push rod (212) on port 1,3 side.
And install spring seat (*218-2) to push
rod on port 2,4 side.
Assembling push rod, spring (246) and seat

(218)
The parts marked * might not be equipped depending on valve type.
(6) Fit plug (211) assy to casing (101).
1. When the force of spring (211) is weak, it

stops at the position where it is pushed in
by the sliding resistance of O-ring (214).
Installing plug assy
33-97
2. When the force of spring (221) is strong,

attach plate (151) and press 4 push rods
by hand at the same time, and tighten joint
(301) temporarily.
-Install spool (201) straight and evenly into
the hole of casing (101).
-Take care so that plug (211) and plate
(151) do not jump out of casing (101).
Installing plug assy and plate (151)
(7) Install joint (301) on casing (101) with jig A

securely.
Jig A : See 33.2.3.7 JIG.
Tightening torque : 47.1N-m (32.8 to 37.2
lbf-ft)
Installing joint (301)
(8) Install circular plate (302) to joint (301)

(9) Screw adjusting nut (312) in until it touches
circular plate (302), and tighten it applying
spanner to stop circular plate returning.
Tools: Socket: 22mm
-Apply Loctite #277 to threads of joint.
Tightening torque: 68.6N-m (51 lbf-ft)
Installing circular plate (302)
-Screw it in until it comes in contact with 4 push rods (212) equally.

-The exceeding of screw in may cause malfunction of machine.
33-98
(10) Apply heat-resisting grease to joint (301)

rotating section and the top of push rod
(212).
33
(11) Cover it with boots.
(12) Spray rust preventives through each port
and attach plug respectively.
Applying grease to joint section and push rod
33-99

Check item Standard Remarks
When leakage quantity reaches to 1000 cc/
min. or more where handle is set in neutral
Conditions
position, or to 2000 cc/min. or more in
Leakage Primary pressure 2.94 MPa (426 psi)
operation, replace spool with new one.
Hydraulic oil viscosity 23 cSt
If leaked, even if the spool is replaced,
replace pilot valve assy with new one.
When the wear of sliding section is 10 μm
This condition may be the same as the
Spool more than the that of non sliding section,
above.
replace it with new one.
Push rod When the wear of top is 1 mm (0.04 in) or more, replace it with new one.
When looseness of 2 mm (0.08 in) or more
Looseness of control on circular plate (302) on control section and In case of the looseness due to the
section joint section (301) due to wear is produced, loosening on tightening section, adjust it.
replace them with new ones.
When trouble such as noise, hunting, drop of
primary pressure, etc. has occurred in op-
eration, and it does not restore after taking
Stability of operation
corrective action according to below 33.2.3.6
(TROUBLESHOOTING), replace pilot valve
assy with new one.
-O-ring, etc. should be replaced with new one at every disassembling.

-If socket bolt (125) was loosened, seal washer (121) should be replaced.
33-100
It is very difficult to find defective section. The following table explains the several estimated causes.
For repair, refer to the estimated causes and corrective actions.
33
The following table explains general phenomenon, estimated causes and corrective actions. However,
most machine problems are not caused by the failure of only one part, but involve relations with
other parts. Therefore corrective action other than those described in this table is often required. The
following table does not cover causes and corrective actions for all the troubles. So it may be
necessary to perform further investigation of troubles and causes.
Phenomenon Possible Cause Corrective action

1. 1.
Primary pressure is insufficient. Secure primary pressure.
2. 2.
Secondary pressure springs (241) are Replace with new ones.
broken or fatigued.
Secondary pressure
3. 3.
does not rise.
Clearance between spool (201) and cas-ing Replace spool (201).
(101) is abnormally large.
4. 4.
Handle has a looseness. Disassembly and reassembly or replace
handle section.
1. 1.
Sliding parts are caught. Repair the unsmoothed section.
Secondary pressure 2. 2.
is unstable. Tank line pressure varies. Bring pressure directly to oil tank.
3. 3.
Air has mixed into pipeline. Bleed air by operating it several times.
1. 1.
Secondary pressure Tank line pressure is high. Bring pressure directly to oil tank.
is high. 2. 2.
Sliding parts are caught. Correct.
33-101
33.2.3.7 JIG
(1) Jig for removing and installing joint (301)
33-102
33.2.4 PILOT VALVE (FOR TRAVEL)

33.2.4.1 CONSTRUCTION 33
Pilot valve (Travel)
Torque Torque
101 CASING 1 29.4 (22) 251 RO PLUG 3
102 CASING (DAMPER) 1 6.9 (5.1) 252 PLUG 6
191 SEAT 1 2 253 RO PLUG 2
192 SEAT 2 2 261 O-RING 3
193 BUSHING 2 2 263 O-RING 2
194 STEEL BALL 2 8.8 (6.5) 271 SOCKET BOLT 4
201 COVER 2 301 SPOOL 4
202 PLUG 4 311 SPRING SEAT 4
203 GREASE CUP 4 313 WASHER 4
210 PACKING 4 324 SPRING 4
213 O-RING 2 413 CAM SHAFT 2
214 PUSH ROD 4 414 BUSHING 4
217 SHIM 4 420 CAM 2
218 SPRING SEAT 4 471 STEEL BALL 4
224 PISTON 4 6.9 (5.1) 472 SET SCREW 2
225 STEEL BALL 12 501 BELLOWS (BOOTS) 2
33-103

(1) Special jig for disassembly and assembly
Special jig 1(for removal of bushing)
(2) Precautions for disassembly and assembly

1. Disassemble and assemble the pilot valve paying attention to the rust protection for dust, dirt, etc.
in order not to allow them to enter in.
2. Handle parts carefully not to damage.
3. Write down the installing positions of respective part during disassembly, and assemble respective
part to the position as they were before.
(3) Disassembly
1. Stop respective port (P, T, 1, 2, 3, 4, 5 and 6) of the valve with plugs and clean the outer
surface.
2. Fix the cleaned valve with vise.
3. Remove bellows (501) from cover (201).
4. Remove set screw (472).
5. Contact pry bar (ø7 or less) to one end of cam shaft (413), and strike it lightly with a hammer.
6. Remove cam (420).
7. Remove socket bolt (271).
9. Remove the casing upper assembly and fix the assembly with vise, again.
10. Draw push rod (214) out of plug (202).
11. Remove plug (202) with grease cup (203), packing (210) and O-ring (212).
12. Remove piston (224).
13. Remove damping spring (336) from the casing.
14. Take out spring seat (218) from casing (102) with tweezers.
15. Take out steel ball (225) using magnet.
16. Fix the lower casing assy with vise, and take out O-rings (211,213) from casing (101).
17. Remove reduction unit valve assembly and return spring (335) from casing (101).
18. Place cover (201) on the flat bench transverse, apply bushing (414) to special jig 1, strike it lightly
with hammer, and pull the bushing out.
33-104
19. For disassembly of the reduction unit valve assy first push spring seat (311) in and shift the
spring seat crosswise making secondary pressure spring (324), remove it from spool (301)
passing through the large hole.
33
・ Handle the assembled unit as an assembly.
20. Separate spool (301), spring (324) for secondary pressure setting, shim (217) and washer.
・ Handle the assembled unit as a assy. And there may be unit on which washer is not installed.
21. Remove grease cup (203) from plug (202).

22. Remove O-ring (212) from plug (202).
(4) Assembly
1. Clean all parts before assembly, and dry them by means of compressed air. Do not use rag.
・ Repair the parts damaged when being disassembled, clean them, apply oil to the moving section,
and install the same parts on the positions where they are before.
・ Replace every O-ring and packing with new ones.
2. Install washer (313), shim (217), spring (324) for resetting the secondary pressure, and spring
seat on spool (301) in order.
3. Pass spool (301) through the larger hole of spring seat (311), push the spring seat in , and install
it making the spring for the secondary pressure flex and shifting the spring seat crosswise.
4. Fix casing (101) with vise, and place spring (335) for return in casing (101).
5. Place the reduction unit subassy described in Articles 2. and 3. in casing (101).
・ Install them on the positions as they were before.

・ When placing the reduction unit subassy in, pay attention to the spool lower end so as not to
bring into contact with the corner of the casing.
33-105
6. Place O-rings (211,213) in casing (101).

7. Fix upper casing (102) with vise and place the steel ball in it.
8. Place spring seat (218) in casing (102) with tweezers.
9. Place damping spring (336) in casing (102).
10. Install piston (224).
11. Place O-ring (212) in plug (202).
12. Place packing (210) in plug (202).
・ Pay attention to the direction when placing the packing in.

・ Apply grease slightly before placing packing in.
13. Place grease cup (203) in plug (202).

14. Install push rod (214) on plug (202).
15. Place the push rod subassy which is sub-assembled by the procedures in Articles 11) to 14) in
casing (102).
16. Put cover (201) on the flat work bench, press bushing (414) with special jig 1, and press fit the
bushing striking lightly.
17. Fix the lower cover assy which is assembled by the procedures in Articles 2) to 6) with vise, and
install the upper cover assy which is assembled by the procedures in Articles 7 to 15) on it.
18. Install cover (201) on casing (102).
19. Tighten socket bolt (271) to the specified torque.
20. Install cam (420) on cover (201).
21. Insert cam shaft (413) from the outside pressing cam (420).
22. Apply Loctite #241 or equivalent to the thread of socket bolt.
23. Tighten socket set bolt (472) to the specified torque.
24. Incline cam (420), apply grease to the top end of push rod (214), and fill grease cup (203) of
plug (202) with grease.
25. After fitting the top end of bellows (501) in cam (402), fit the lower side in the groove of cover
(201).
33-106
Phenomenon Cause Corrective action
Secondary pressure 1. 1. 33
does not rise. Insufficient primary pressure Secure primary pressure.
2. 2.
Permanent set in fatigue of spring (324) for Replace it with new one.
setting of secondary pressure.
3. 3.
The gap between spool and casing is too Replace it with complete remote control
large. valve.
4. 4.
The control section is loosened. Replace parts of control section.
is unstable. Sliding part is not smooth. Repair unsmooth section.
2. 2.
Variation of pressure of tank line Return oil to oil tank directly.
3. 3.
Air contamination in piping Bleed air by operating several times.
is high. Pressure of tank line is high. Return oil to oil tank directly.
2. 2.
Sliding part is not smooth. Repair unsmooth section.
Damping does not 1. 1.
work. Air is accumulated in piston chamber. Bleed air by operating several times.
2. 2.
Sliding part is not smooth. Repair unsmooth section.
3. 3.
Permanent set in fatigue of damping spring Replace it with new one.
(336)
4. 4.
Gap between damping piston (224) and Replace it with complete remote control
casing (damper) (102) is too large. valve.
5. 5.
Malfunction of check valve Disassemble and check on check valve
section.
6. 6.
Orifice of damping piston (224) is too large. Replace damping piston.
Damping torque is 1. 1.
heavy. Sliding part is not smooth. Repair unsmooth section.
2. 2.
Orifice of damping piston (224) is clogged. Repair or replace damping piston.
33-107

(1) Swing motor Composition
Swing motor
33-108
Torque Torque
M-1 TAPERED ROLLER 1 M-21 PISTON ASSY 7 33
BEARING M-22 RETURN PLATE 1
M-3 FRICTION PLATE 1 M-23 CAM PLATE 1
M-4 SEPARATOR PALATE 2 M-24 LEVEL GAUGE 1
M-5 SNAP SING 2 M-25 O-RING 1
M-6 NEEDLE BEARING 1 M-26 HOUSING 1
M-7 O-RING 1 M-27 COLLAR 1
M-8 O-RING 1 M-28 OIL SEAL 1
M-9 O-RING 1 M-30 BACK UP RING 2
M-10 BALANCE PLATE 1 M-31 O-RING : 1B P21 2
M-11 PISTON 2 M-33 BACK UP RING 2
M-12 TEFLON RING 2 M-34 O-RING : 1B P26 2
M-13 PLUG ; PT 1/4 2 M-35 PARALLEL PIN 2
M-14 BUSHING 4 M-36 PLUG : PF3/8 1
M-15 SCROLL WAVE 4 M-37 O-RING : 1B P14 1
M-16 TEFLON RING 4 M-38 SOCKET BOLT : M12X30 4
M-17 SPRING 13 M-39 COVER 1
M-18 PISTON 1 M-40 PLUG 1
M-19 CYLINDER 1 70 RELIEF VALVE ASSY 2
M-20 RETAINING SPRING 1 100 BY-BASS VALVE ASSY 2
1. Relief and check valve assy (70)
2. By-pass valve assy (100)
33-109
(2) Swing reduction unit
Swing reduction unit
Torque Torque
R-1 PINION SHAFT 1 R-15 HOLDER 2 ASSY 1
R-2 COLLAR 1 R-16 NEEDLE BEARING 6
R-3 PLATE 1 R-17 SHAFT 2 3
R-4 TAPER ROLLER BEARING 1 R-18 SPUR GEAR 5 3
R-5 GEAR CASE 1 R-19 THRUST PLATE 2 6
R-6 GREASE NIPPLE 1 R-20 SPRING PIN : 8X5 3
R-7 OIL SEAL 1 R-21 HOLDER 2 1
R-8 TAPER ROLLER BEARING 1 R-22 COLLAR 2
R-9 PIN 2 R-23 RELIEF NIPPLE 1
R-10 RING GEAR 1
R-11 SPUR GEAR 4 1
R-12 SUN GEAR 1
R-13 HOLDER 1 ASSY 1
R-14 SOCKET BOLT : M12X95 6
33-110
33.2.5.2 DISASSEMBLY AND ASSEMBLY OF SWING MOTOR

(1) Disassembly
1. Remove the relief assy (70).
33
Tools: Socket: 27 mm
2. Remove the by-pass valve (100).
Removing relief valve assy and by-pass valve
Install it in the original position.
3. Apply match mark on cover (39) and

housing (26).
Maching marks on cover and housing
4. Remove socket bolt (38).

Removing cover mounting bolts
33-111
5. Lift up and remove cover (39).
Removing cover
6. Remove snap ring (5) with plier.

7. Remove inner race of needle bearing (6).
Removing bearing (6) inner race
8. Remove the O-ring (9).
Removing O-ring (9)
9. Remove the balance plate (10).
Removing balance plate
33-112
10. Remove the bushing (14) with a teflon

ring (16) on it, and the scroll wave (15).
33
Removing bushing (14) and scrollwave (15)
11. Remove spring (17) from brake piston (18).
Removing spring (17)
Fit spring in the original position.
12. Remove brake piston (18).
Removing brake piston (18)
The O-ring (7) (8) make it difficult to slide the piston (18) easily from the housing (26). For this
reason, use tapped hole (M6) provided in the piston (18) to remove it, as shown in the above Fig.
33-113
13. Remove the separator plate (4) and friction

plate (3).
Removing separator plate (4) and friction

plate (3)
14. Remove cylinder assy (19) from housing

(26).
Removing cylinder assy (19)
-Oil seal (28) and outer race of taper roller bearing (1) are left in housing.
-Take care not to damage the sliding surface on upper section of cylinder housing.
-Assemble piston bore of cylinder (19) and piston assy (21) in the same original combination.
15. Remove the outer race of tapered roller

bearing (1) from the housing.
Removing outer race of tapered roller bearing

(1)
33-114
16. Remove oil seal (28) from housing (26)

with driver and hammer.
33
-The reuse of the removed oil seal is not
allowed.
Removing oil seal (28)
17. Removing the cylinder assy.
a. Attach an gear puller to two positions of

the inner race of the tapered roller bearing
(1) and to the splined end of the cylinder
(19), and pull out the inner race along
with the collar (27).
Pulling inner race of tapered roller bearing (1)
b. Remove the cam plate (23), piston assy

(21) and return plate (22) together from
the cylinder (19).
Removing cam plate (23), piston assy (21)

and return plate (22)
33-115
c. Remove cam plate (23) from the piston

assy (21) as is by sliding it on sliding
surface of piston assy (21).
Removing cam plate (23)
Handle cam plate with care so as not to damage its sliding surface.
d. Remove retaining spring (20) from cylinder

(19).
Removing retaining spring (20)
33-116
(2) Installation
Install swing motor unit in the reverse procedure of disassembling.
33
1. Jigs
Jig used for installing is not provided with part number.
2. Assembling relief assy

Fit relief assy (70) to cover (39).
Assembling relief assy (70)
3. Confirming correct assembly

Open the brake release port, apply a pilot
pressure of 1.96 MPa (280 psi) to the P
port and confirm that the output shaft
rotates more than 1 turn smoothly by
19.6~29.4 N-m (14~22 lbf-ft) torque. In case
the output shaft does not rotate,
disassemble it again and readjust.
Confirming correct assembly
33-117
33.2.5.3 DISASSEMBLY AND ASSEMBLY OF SWING REDUCTION UNIT

(1) Removal
1. Remove the sun gear (12) and then
remove the holder 1 assy (13).
-Because the shafts in the holder 1 assy

(13) are press-fit in the holder (1), and
caulked at the end, further removal of the
assy is impossible.
Removing spring pin (20)
2. Remove spur gear 4 (11) and then

remove the holder 2 assy (15).
3. Removing the holder 2 assy (15).
a.
Drive the spring pin (20) through the holder
2 assy (15).
-The spring pin (20) cannot be reused.
b.
Holding spur gear 5 (18) with your hand,
remove the shaft 2 (17) from holder 2 (15). Removing shaft (17)
4. Remove the ring gear (10).
-The mating surface between the ring gear

(10) and the gear case (5) is coated with
liquid packing (Three Bond #1215, gray) to
prevent oil leakage. Use the notch in the
gear case (5) to remove the ring gear (10).
5. Removing the collar (16).
Remove the collar (16) from the shaft (1)
by tapping the collar with a screwdriver and Removing ring gear (10)
hammer.
6. Removing the shaft (1) assy.

Place blocks about 300 mm high under
the flange of the gear case (5) to allow
removal of the shaft (1) and push the end
of the shaft with a hydraulic press to
remove the shaft (1), collar (2), plate (3)
and taper roller bearing (4) as an assy.
7. Remove the oil seals (7) from the gear
case (5).
Removing shaft (1) assy
33-118
33
-Do not remove any further, unless the bearings etc. are abnormal.
-Do not reuse the oil seals.
(2) Installation
The jigs to be used for installation are shown below.
1. Apply grease to the rollers of the taper

roller bearing (4).
-Grade : SHELL ALVANA EP2 or equivalent
(grease for extreme pressure duty)
-Quantity : About 150cc (9.15 cu-in)
Applying grease to taper roller bearing (4)
2. Press-fitting the oil seal (7)

Degrease the oil seal position on the gear
case (5) and the oil seal (7). Apply liquid
packing (Three Bond #1211, white) to the
outside of the oil seal. Using the seal
press-fitting jig and a hand press, install the
oil seal (7) on the gear case (5).
Press-fitting oil seal (7)
-After press-fitting, apply grease to the oil
seal lips.
33-119
3. Place the gear case (5) with the output

shaft side facing upward, and install the
pinion shaft (1) assy into the gear case (5).
-Use the seal protector to prevent the

spline of the pinion shaft (1) from damaging
the lips of the oil seal (7).
Installing pinion shaft (1) assy
4. Installing the taper roller bearing (8)

Place gear case (5) directing pinion shaft
downward, warm collar (22) of taper roller
bearing to temperature adding +50 degC
(122 degF) to the room temperature and fit
it.
Installing taper roller bearing (8)
5. Installing the collar (22)

The nominal thickness of the collar (22) is
7.0 mm (0.2756 in). Adjust this thickness
so that the clearance between the collar
(22) and the groove in the shaft (1) is 0.06
mm (0.0024 in).
Adjusting clearance between collar (22) and

shaft (1)
33-120
6. Installing the ring gear (10).
・ Degrease the mating surface between the

33
gear case (5) and the ring gear (10) and
the pin (9).
・ Apply liquid packing (Three Bond #1215,
gray) to the area of the gear case (5)
inside the bolt circle, and install the ring
gear (10) on the gear case (5).
・ Apply sealant equally so that the thickness
projecting from nozzle is about 1.5 mm
Applying liquid packing to gear case (5)
(0.06 in) in diameter.
Installing ring gear (10)
7. Installing the holder 2 assy (15)
a. Install the needle bearing (16) in spur

gear 5 (18). Install this assy together with
the thrust plate 2 (19) into holder 2 (21),
and insert the shaft 2 (17) into the spur
gear.
-Apply hydraulic oil to the inside diameter

of spur gear 5 (18), needle bearing (16)
and the outside diameter of the shaft 2
(17).
Installing holder assy 2 (15)
33-121
b. Drive the spring pin (20)
Drive spring pin facing the split to gear side.
Driving spring pin (20)
8. Carefully mesh the holder 2 assy (15) in

the internal teeth of the ring gear (10),
and the spline of the pinion shaft (1) with
its mating part. In this condition, insert the
holder 2 assy (15) while turning it.
9. Carefully mesh spur gear 4 (11) in the spur
gear 5 (18).
Inserting holder 2 assy (15)
10. Installing the holder 1 assy (13)

a.
Carefully mesh the holder 1 assy (13) in
the internal teeth of the ring gear (10),
and holder 1 (13) in the teeth of sun gear
(12). In this condition, insert the holder 1
assy (13) while turning it slowly.
b.
Place sun gear (12) in while engaging
with planet gear of holder 1 assy (13)
slowly.
Inserting holder 1 assy (13)
11. Turn the holder 1 assy (13) with your
hand to confirm that the pinion shaft rotates
smoothly.
33-122

Parts Maintenance
Gear, Pinion Replace if harmful wear, pitting, peeling, scratch, etc. are found on the tooth face. 33
Replace if harmful wear, indentation, etc. are found on the spline portion, there is a
Holder 1, 2 assy backlash on the pin portion (For holder 1 assy, loosening of caulking, for holder 2
assy, wear of pin bore), or the needle bearing is worn making a backlash.
Even if the bearing works normally, when the "Hour meter" arrives to the time in
3000 hours, replace them with new ones.
Taper roller bearing, Even through the "Hour meter" is within 3000 hours, when the rolling contact
Needle bearing surface of needle bearing is flawed while removing, replace them with new ones.
And if possible we will recommend that you replace bearings with new ones
because they will often be damaged during removing.
When the lip is damaged, replace it with a new one.
Oil seal And even if there is no leak, replace seal every 3000 hours.
Also, replace it with new ones without fail while installation.
Other parts Replace parts worn or damaged with new ones.
33-123
33.2.6 SWIVEL JOINT

33.2.6.1 CONSTRUCTION VIEW
Construction of swivel joint

1 BODY 1 8 O-RING 2
2 STEM 1 9 SOCKET BOLT (M8X20) 3
3 THRUST PLATE 1 10 SOCKET BOLT (M8X30) 1
4 COVER 1 11 PLUG : PT1/8 3
5 SEAL 7 12 PLUG : PF1/4 2
6 SEAL 1 13 PLUG : PT3/8 1
7 O-RING (G95 1A) 1 16 O-RING 2
33-124

33.2.6.2.1 Tools
33
33.2.6.2.2 Apparatus
(1) Hoist or crane
The lifting device should be capable of lifting the swivel joint assy.
(2) Work bench
The work bench should have an area of 1.2mX1.5m (4ftX5ft).
(3) Others
Also prepare cloth, wooden block and oil pan.
33.2.6.2.3 Cleaning outside

Clean the swivel joint to be free from dirt and dust, using steam and cleaning oil.
・ Keep all ports plugged up while cleaning.
33-125
33.2.6.2.4 Disassembly
The part numbers used in this disassembly procedure correspond to those of a construction drawing in
Fig."Construction of swivel joint".
(1) Removing cover

1. Mark cover (4) and body (1) with matching
marks for convenient reassembly.
2. Place a V-block on a work bench, place a
swivel joint set on the side, fix it and
loosen socket bolt (10) by means of a
pipe and wrench. Alternately, the swivel
joint may be fixed by holding stem (2) in a
vise.
Removing cover (4)
3. Remove cover (4) from body (1) and draw

out O-ring (7) from cover (4).
Removing O-ring (7)
(2) Removing thrust plate

Loosen socket bolt (9) fastening thrust plate (3),
in the same manner as the removing of the
above-mentioned cover.
Removing thrust plate (3)
When removing thrust plate (3) by fixing body (1), support stem (2) so it may not fall down.
33-126
(3) Removing stem

Place body (1) on a V-block. Put a wooden
block against stem (2) via the body so about
33
half of the stem is covered by the wooden
block and knock it out using a mallet.
By hitting out the stem over about 1/2 from
the body, it can be easily pulled out by hand.
Stem weight: 13kg (29 lbs)
Drawing out stem (2)
(4) Removing sealing parts

1. Remove rings (8) of seal assemblies (6)
and (5) with spatula (f).
Removing O-ring (8)
Pay attention to the body (1) not to be damaged by the top edge of spatula (f).
2. Pierce slipper ring of seal assemblies (6)

and (5) with pin (e) and remove them
from the seal groove. Right Fig. shows only
one pin, but use two pins to remove it
securely.
Removing out seal assy (5)(6)
33-127
33.2.6.2.5 Assembly
Prior to assembly, clean each parts (excluding the O-ring and seal), and arrange in the sequence of
assembly.
Apply grease on the groove of seal to be installed on seal assembly (6) and O-ring (8).
(1) Assembling seals to body

1. Apply hydraulic oil to O-ring (8) thinly and insert it in O-ring groove.
Check the twist of O-ring
2. Slipper ring is assembled, after first

inserting the backup ring, by
slightly-distorting the shape as shown in
Right Fig. Also after inserting all of the
seals, be certain that these are installed in
the seal groove by use of the spatula.
3. Assemble seal (5) by the same procedure
above mentioned.
Inserting slipper ring (6)
Remove grease, hydraulic oil and vaseline from the groove of seal.
And insert seal (5).
Seals (5) have no back-up ring.
(2) Assembling stem

Lightly coat the outer circumference of stem
(2) and the inner surface of body (1) with
grease or vaseline and slowly insert stem (2)
into body (1).
Inserting stem (2)
-If stem (2) is pressed in too fast, the seal may be damaged. Do it slowly.
-The clearance between body (1) and stem (2) is about 0.1mm (0.004in). Push stem straight along
the shaft center.
33-128
(3) Assembling thrust plate

1. While holding stem (2) and body (1), match
the hole of thrust plate (3) and the stem
33
(2) hole.
2. Next, after removing any oil from the thread
of socket bolt (9), coat it with Loctite #242
and tighten to stem (2).
Tools: Allen wrench: 6mm,
Tightening torque: 30.4N-m (22lbf-ft)
Tightening socket bolt (9)
(4) Assembling cover

After installing O-ring (7) to cover (4) and
aligning the matching marks of the cover (4)
and body (1), coat socket bolt (10) with Loctite
#242 and tighten it which will then complete
assembly.
Tools: Allen wrench: 6mm,
Tightening torque : 30.4N-m (22lbf-ft)
Tightening socket bolt (10)
33-129

33.2.6.3.1 USABLE LIMIT OF PARTS
33-130
33.2.6.3.2 INSPECTION AFTER ASSEMBLY

After completion of assembly, inspection for oil leakage, pressure resistance, etc., using a device as
shown in Right Fig.
33
(1) High pressure port
Install a directional valve and pressure
gauge to the stem side port and body
side port respectively, and while watching
the pressure gauge (for high pressure)
installed on the body side and also by
regulating high pressure relief valve (7),
gradually increase the pressure and when
the pressure has reached 1.5 times the
maximum working pressure, close stop
valve (3) and lock in the hydraulic oil in
the swivel. Keep stop valve (6) on the low
pressure relief valve side closed at this
time.
Check that it is free from looseness,
deformation, breakage, etc. under three
minutes pressurizing.
And, the oil leakage must be checked for
the first 1 minute, and if there be a
pressure drop for any reason, the pressure
drop should be in 10% of the trapped Hydraulic circuit for inspection equipment
pressure.
This checking must be carried out for every
circuit.
(2) Low pressure port (Drain port, return port,

etc.)
Similar to the high pressure port, install a
directional valve and pressure gauge on
each port of the stem side and body side.
Open stop valve (6) on the side of low
pressure relief valve (5) and while
watching the pressure gauge (for low
pressure) connected to the body side and
also by regulating low pressure relief valve
(5), gradually increase the pressure and
check for outside leakage with a color
check at a pressure of 0.49 MPa (71 psi).
・ The maximum working pressure stands for pressure of hydraulic excavator equipped with swivel
joint.
33-131
33.2.6.3.3 TROUBLESHOOTING
Trouble Cause Remedy
1.
External leakage of hydraulic oil Defective O-ring & seal Replace all seals.
2. 1) 1)
Internal leakage of hydraulic oil Defective slipper seal Replace all seals.
2) 2)
Sliding face worn excessively Replace assy.
3. 1) 1)
Swivel stem seized Stem and body seized Grind and hone.
Replace assy, if stem and body are too
loose and causing oil leakage.
2) 2)
Inappropriate swivel stopper Reinstall
bracket Secure 2 to 3 mm (0.08 to 0.12 in)
allowance for bolt stopper.
4.
Loose swivel stem and cover Socket bolt tightened Retighten to specified torque.
insufficiently.
33-132
［34. TRAVEL SYSTEM］
34
34. TRAVEL SYSTEM
TABLE OF CONTENTS

34.1.1 TRAVEL SYSTEM …………………………………………………………………………………………34-3
34.1.2 CRAWLER …………………………………………………………………………………………………34-3
34.1.3 UPPER ROLLER …………………………………………………………………………………………34-8
34.1.4 LOWER ROLLER (TRACK ROLLER) …………………………………………………………………34-14
34.1.5 FRONT IDLER (IDLER ADJUSTER ASSY) …………………………………………………………34-21
34.1.6 SPROCKET …………………………………………………………………………………………………34-31
34.1.7 TRAVEL MOTOR …………………………………………………………………………………………34-33
34.1.8 SWING BEARING …………………………………………………………………………………………34-36
34.2.1 TRAVEL MOTOR …………………………………………………………………………………………34-41
34-1

S5YT3415E01
(AUS)
PREFACE
(1) This Manual describes all the procedures from removing to attaching, arranging them by item.
(2) This Manual consists of first part. Removing and attaching, and sequel. Disassembling and
assembling.
(3) The removing and attaching can be performed in the procedure specified in Table of Contents, but
in view of actual repairing or time saving some process can be omitted.
(4) The removing and attaching procedure does not completely cover all possible situations because of
(5) Please be aware that the procedure to be followed must be determined according to the above
conditions.
When disassembly and assembly are required, select the necessary section, itemize the work
contents with good understanding, then starts working.
34-2
34.1.1 TRAVEL SYSTEM
34
Designation and location of undercarriage
34.1.2 CRAWLER
34.1.2.1 REMOVING CRAWLER
(1) Position the machine to remove crawler.
(2) Pushing out master pin.
1.
Find the master pin and place it in its
removing/fixing position in right Fig..
2.
Loosen the grease nipple and slacken crawler.
Crawler removing position
-When loosening the grease nipple of the adjuster, do not loosen it more than one turn.
-Where grease does not come out well, move the machine back and forth. The over loosening of
grease nipple may cause it to jump out incurring danger of injury. So be careful not to over loosen
the grease nipple.
34-3
3.
Pushing out master pin
Apply jig on master pin and strike it out with a
mallet.
(Refer to 34.1.2.2(4) Fig. "Press fitting of master
pin")
Removing/fixing position of master pin
When using a big hammer, wear protective goggles and a long-sleeved uniform so you do not injure
yourself by flying objects.
(3) Removing crawler

Put attachment on ground so that weight is
not loaded to the lower frame, and remove
track link assy rotating sprocket.
Removing crawler
Crawler end section may fall on the ground just before extending it on the ground incurring danger of
injury.
Please keep well away from the equipment.
34-4
34.1.2.2 INSTALLING
(1) Checking crawler installation direction.

Place the track links on the ground so they
converge, facing the front idler, as shown
in the figure on the right.
34
Installing direction of crawler
(2) Installing crawler

1. Preparation for installation
Treat paint flaking protection with care not
to damage lower flame.
2. Winding crawler
Insert bar into master pin hole, lift lower
frame up 1 or 2 cm (0.4 in~0.8 in) using
attachment and hold it, then turn sprocket
in rearward positioning the machine so
that the weight is not loaded to shoe.
(3) Preparation for press fitting master pin Winding crawler
1. Preparing for installation
Put square wood under the shoe plate.
2. Aligning master pin holes
Aligning master pin holes through fine
adjustment turning sprocket.
Preparation for press fitting master pin
-When using a big hammer, exercise care so you are not injured by flying objects the same way as
when pushing out the master pin.
-Coat the master pin with molybdenum disulfide grease, before pressing it in.
34-5
(4) Press fitting of master pin

Apply press fitting jig on master pin, and
strike it with a mallet to press fit.
Press fitting of master pin
(5) Adjusting crawler tension (See right Fig.)

After installing, adjust tension of crawler.
Adjusting crawler tension
Shoe assy
34-6
34
34.1.2.5 TOOLS AND JIGS

(1) Tightening tools (2) Jig
34-7
34.1.3 UPPER ROLLER

34.1.3.1 UPPER ROLLER ASSY
Upper roller assy
34.1.3.2 REMOVING
Remove crawler (Above mentioned).
(2) Removing upper roller (1)
1.
Remove nuts on support tightening
section, and also remove capscrew (2)
M16X90.
Removing upper roller (1)
34.1.3.3 INSTALLING
(1) Inspection
Before reassembling, check it that it
rotates smooth manually and for leak.
(2) Installing upper roller (1)
1.
Fit it directing nut toward idler side.
2.
Insert it until collar comes in contact with
support.
3.
Fit it directing the countersinking mark of
shaft end upward. Installing upper roller (1)
4.
Apply Loctite #262 on capscrew M16X90,
and tighten it to the specified torque.
Tightening torque: 279 N-m (210 lbf-ft)
Installing upper roller (1)
34-8
34
Construction of upper roller

(1) Disassembly
1. Draining out oil
Remove plug (10) and drain out oil.
2. Removing snap ring (9)
Mount the end face inside upper roller (1)
on stand jig (f) and separate snap ring
(9), using snap ring pliers.
3. Removing cover (4)
Take off cover (4) upwards, utilizing the
screwed hole for the plug.
Removing snap ring (9), cover (4), O-ring (7),

plate (3)
4. Removing O-ring (7)

Separate O-ring (7) from cover (4).
5. Removing plate (3)
Loosen 2 socket bolts (8) and draw out
plate (3) from roller (1).
6. Removing shaft (2)
Put the extrusion jig (g) against the end
face of shaft (2) and push shaft (2) with
collar (11) for floating seal (6), using a
press or hammer.
Extruding shaft (2)
34-9
7. Removing floating seal (6).

Take out floating seal (6) from roller (1).
Taking out floating seal (6)
8. Removing floating seal (6).

Remove from collar (3), floating seal (6)
that is located on the side from which shaft
(2) was disassembled.
Removing floating seal (6)
Collar (3) is press fitted into shaft (2). Therefore do not disassemble it.
9. Removing bushing (5)

Since the bushing is thin, machine it on a
lathe or scrape it off, take care so as not
to damage the bore of roller (1).
If the bushing is not worn much, mount
upper roller (1) on jig (f), insert jig (g) into
the end face of bushing (5) and push it out
with a press.
Pushing in bushing (5)
(2) Assembly
Assembly of the upper roller is done in the reverse order of disassembly.
1. Pressing the bushing (5).

Align inner hole of roller (1) and bushing
(5) and press fit it vertically with press so
that jig (h) for bushing push-in jig (h) is
inserted into bushing (5).
Pushing in bushing (5)
34-10
If you fail in this operation by pressing the bushing unevenly, the bushing is distorted and gets
unserviceable. In that case, do not re-use the bushing as it may develop malfunctioning after assembly.
2. Installing floating seals (6).

Two floating seals (6) make a pair. Attach
one floating seal to retainer fixed in shaft 34
(2), and another to the inside of upper
roller (1).
-Prior to placing floating seal (6) in, apply
engine oil lightly to seal surface.
Installing floating seal (6)
3. Inserting shaft (2).

Coat shaft (2) with a thin film of oil and
insert it into upper roller (1).
4. Installing plate (3).
Mount upper roller (1) on the stand jig (f)
and attach plate (3) to the end face of the
shaft with socket bolt (8). In that case, coat
the screwed part of socket bolt (8) with
Loctite #242 beforehand.
Tightening torque : 33 N-m (25 lbf-ft) Pressing the shaft (2)
5. Installing O-ring (7).

Fit O-ring (7) to the groove of cover (4).
-Apply grease to O-ring.
6. Installing cover (4).
Attach cover (4) to upper roller (1). Use a
press in this operation as a press fit is
used.
7. Installing snap ring (9).
Fix snap ring (9) into upper roller (1), using
snap ring pliers.
Installing plate (3), O-ring (7), cover (4), snap
ring (9)
34-11
8. Filling oil
Fill in 20 cc (1.22 cuoin) of engine oil API
grade CD #30 through the plug hole in
cover (4).
9. Installing plug (10).
Place seal tape around plug (10) and
screw it into the plug hole of cover (4).
-After assembling the upper roller, confirm
that oil is not leaking from it and that it
rotates smoothly by hand.
Filling oil
34-12
34
34-13
34.1.4 LOWER ROLLER (TRACK ROLLER)

34.1.4.1 LOWER ROLLER ASSY
Lower roller assy
34.1.4.2 REMOVAL
1. Preparation for removal
Loosen grease nipple to slacken the link.
Put wood blocks on the front and rear
sides of under section of lower frame, and
stabilize the machine.
2. Removing lower roller
Remove capscrew (2) M14X55.
Tools: Socket: 22mm
Weight of lower roller : Approx.15 kg (33
Holding up the lower frame
lbs)
(2) Where crawler is installed

1. Preparation for removal
Slacken crawler, and stop engine keeping
lower frame lifted up with front attachment.
2. Put safe blocks under the front and rear
sides of lower frame.
3. Remove lower roller
Remove capscrews (2) in the same
procedure as that shown in Fig. "Lower
roller assy".
Removing lower roller
(1) Securing lower roller temporarily
Apply Loctite #262 on 4 capscrews (2)
and tighten them temporarily.
(2) Securing lower roller regularly.
Tighten capscrews (2) to the specified
torque.
(3) Adjusting tension of crawler.
Tighten grease nipple and fill it with grease.
Adjusting tension of crawler
34-14
34
Construction of lower roller

(1) Disassembly
1. Drain oil
Remove plug (8) and drain out oil.
2. Removing pin (4)
Put both ends of lower roller assy on the
V-shaped blocks (K), apply push-out bar
(j) on upper end face of pin (4), and push
pin out striking with mallet.
Drawing out collar fixing pin (4)
3. Removing collar (7), O-ring (6)

Put lower roller on jig (m) for repair stand
so that the shaft is perpendicularly located,
apply pushout jig (P) on shaft end on
upper side, and push shaft (2) until the
O-ring separate from collar (7) with press
or mallet, and take out collar (7) and O-ring
(6).
4. Removing shaft (2)
In addition, push out and remove shaft (2)
together with the lower collar (7) and O-ring
(6).
Removing shaft (2), collar (7), O-ring (6)
The shaft (2) extrusion operation may cause the remaining lube oil to flow out. Prepare an oil
container beforehand.
34-15
5. Removing collar (7), O-ring (6)

Insert shaft (2) with collar (7) and O-ring
(6) removed in the said procedure into
roller (1) directing the collar (7) side
upward, and take out collar (7) and O-ring
(6) from shaft (2) in the same procedure as
that described in Item 3).
6. Removing floating seal (5) Removing floating seal (5)
Take out floating seal (5) from collar (7).
7. Removing floating seal (5)

Take out floating seal (5) from roller (1).
Removing floating seal (5)

Since thickness of bushing (3) is thin,
remove it through lathe or strip it with
care not damage inner hole of roller.
When the wear of bushing is not large,
place upper roller (1) on jig (m) for repair
stand and apply the end of push-out jig
on the end face of bushing (3) end, and
push it out striking it with mallet.
Extruding bushing (3)
Hammer the inside surface of roller lightly so as not to damage the surface. Put the extrusion jig (n)
uniformly over the circumference of bushing (3) and extrude it little by little.
(2) Installing
1. Attach O-ring (6) to one side
Install O-ring (6) to shaft groove.
-Replace O-ring with new one.
Attach O-ring (6) to one side
34-16
2. Press fitting bushing (3)

Align inner hole of roller (1) and bushing
(3) and press fit it vertically in capacity of
press fit load, 3600kg (7940 lbs), in the
condition that bushing push-in jig (g) is
inserted into bushing (3).
-Apply molybdenum disulfide grease on
press-fit section of bushing, and press-fit it
in ordinary temperature. 34
-Bushing which fails to press-fit because of Press fitting bushing (3)
the one-side pressing should not be fitted.
3. Press fitting collar (7)

Fit O-ring to the one side of shaft (2)
mating pin hole of collar (7) on which
floating seal (5) is fit with pin hole of shaft
(2) in advance.
-Care should be taken not to damage
O-ring (6) while press-fitting collar (7) to
shaft.
4. Inserting pin (4)
Press-fit pin (4) to pin hole on aligning pin
Inserting pin (4)
holes of shaft (2) and collar (7).
5. Attach floating seal (5) to roller side

Fit floating seal (5) to inner holes on both
ends of roller (1).
-Check that the seal surface is free from
flaws, rusts, etc. before reusing the floating
seal.
6. Inserting roller (1)
Insert roller (1) from the side where collar
(7), O-ring (6) is not press-fitted to the
shaft (2).
Inserting roller (1)
34-17
7. Installing O-ring (6)

Install O-ring (6) to shaft groove.
-Replace O-ring with new one.
8. Press fitting collar (7)
Press-fit collar (7) to shaft (2).
-Press-fit collar (7) on aligning pin (4) hole.
9. Inserting pin (4)
Press-fit pin (4) described in to the pin hole
mating pin hole of collar (7) with pin hole
on the end side of shaft (2).
Installing O-ring (6), collar (7)
10. Filling oil

Remove plug (8) and fill in 90 cc (5.49
cuoin) of engine oil API grade CD #30.
11. Check it for leakage
Before tightening plug (8), check it for
leakage in the condition of air pressure
0.2 MPa (28 psi).
12. Installing plug (8)
Apply oil resistant sealant on plug (8), and
tighten it in the plug hole on the collar (7)
end face. Installing filling oil plug (8)
Tightening torque : 23 Nom (17 lbfoft)
After assembling the lower roller, confirm that oil is not leaking and that the roller rotates smoothly by
hand.
34-18
34
Lower roller (Track roller)
34-19
34-20
34.1.5 FRONT IDLER (IDLER ADJUSTER ASSY)

34.1.5.1 FRONT IDLER ASSY
34
Front idler assy
34.1.5.2 REMOVING
Remove crawler. (Above mentioned)
(2) Removing idler assy
Sling idler assy, and push it forward with
bar.
Weight of front idler assy (one side): 73
kg (160 lbs)
(3) Installing
Installing is done in the reverse order of
removing.
Removing and installation the front idler
Keep away from the front side of front idler.
(4) Where idling assy (1) has to be separated

Loosen capscrew (4), and separate idler
assy (1) from idler adjuster assy (2).
Tools: Socket: 19mm
Weight of idler assy : 45 kg (99 lbs)
Weight of idler adjuster assy : 49 kg (110
lbs)
-The separated idler assy (1) should be

placed on square timbers.
Separating idler assy (1) from idler adjuster
34-21
34.1.5.3 IDLER ASSY

34.1.5.3.1 CONSTRUCTION
Idler assy
34.1.5.3.2 REMOVING AND INSTALLING

(1) Removing
1. Drain oil
Remove plug (8) on the side of collar (3)
to drain.
2. Removing pin (5)
Apply pin push bar (jig R) to the top of
pin, and push out striking bar (jig R)
lightly by hammer. Removing pin (5)
3. Removing collar (3)

Put idler (1) on stand (U), apply push-out
jig (S) on shaft (2), push out shaft (2) with
collar (3), then remove collar (3).
Removing collar (3)
4. Removing collar (3) from shaft (2)

If removal of collar (3) on the opposite side
is required, turn over front idler and
proceed with the procedure described in
Par. 3.
Removing collar (3)
34-22

With idler (1) mounted on the stand, tap
bushing (4) lightly by hammer, while placing
the bushing drawing rod (T) against the
end face of bushing (4) evenly all round, till
it comes out.
6. Removing floating seals (6)
Take out floating seals (6) from idler (1),
Removing bushing (4)
collar (3). If you intend to re-use floating 34
seals (6), confirm that there is no scoring
and rusting on the contact surface and
store the floating seals in pairs by placing
card board between the sealing faces.
7. Removing O-ring (7)
Separate O-ring (7) from shaft (2).
(2) Assembly
1. Pressing in bushing (4)
Align inner hole of idler (1) and bushing (4)
and press fit it vertically with press so that
jig (V) for bushing press-fitting is inserted
into bushing (4).
2. Installing O-ring (7)
Fit O-ring (7) to O-ring groove on shaft (2).
Pressing in bushing (4)
-Apply grease to O-ring
3. Installing collar (3) (See right Fig.)

Press fit the O-ring (7) installed side of
shaft (2) into collar (3), and drive pin (5).
4. Installing floating seal (6)
Fit the half of floating seal (6) on each
side of collar (3) and idler (1).
Installing collar (3), shaft (2)
5. Inserting idler (1)

Insert floating seal (6) fitted side of idler (1)
into shaft (2).
6. Installing floating seal (6)
Fit floating seal (6) on the other side of
idler (1).
Inserting idler (1) and installing floating seal

(6)
34-23
7. Installing collar (3)

Fit the half of floating seal (6) on the
other collar (3), press fit it in shaft (2),
and drive pin (5) in with hummer.
8. Filling oil and Inspection
Fill in 150~160 cc (9.15~9.76 cu-in) of
engine oil API grade CD #30 through the
plug hole of collar (3), wind seal tape and
Installing collar (3) and filling oil
tighten plug (8).
-After installing the idler assy to the idler adjuster assy, make certain that no oil leaks from floating
seal and plug (8) and that idler (1) rotates smoothly.
34.1.5.3.3 MAINTENANCE STANDARD
Front idler
34-24
34.1.5.3.4 TOOLS AND JIGS
34
34-25
34.1.5.4 IDLER ADJUSTER ASSY

34.1.5.4.1 CONSTRUCTION
Idler adjuster assy
34.1.5.4.2 DISASSEMBLY AND ASSEMBLY

(1) Disassembly
1. Spring set special jig
Before disassembling and assembling the
idler adjuster assy, prepare spring setting
jig (V).
Capacity of hydraulic jack : more than 10
tons (22000 lbs)
2. Preparation for working
Place a hydraulic jack between the jig base
and the stand.
Loosen the holding-down nuts of the jig
and draw out the retainer plate upward. Spring set special jig (V)
Large power is needed to set the spring. Prepare a special jig before disassembly and assembly.
34-26
3. Draw out grease cylinder (See Fig. "Idler

adjuster assy".)
Draw out piston (6) from grease cylinder (1)
of the idler adjuster assy.
4. Removing oil seal (8), O-ring (7)
(See Fig. "Idler adjuster assy".)
Remove oil seal (8) and O-ring (7) from
grease cylinder (1).
5. Slinging work idler adjuster 34
Set the idler adjuster assy on the stand of
the jig, with its bracket (2) side facing up.
Slinging work idler adjuster
6. Fixing idler adjuster assy

Fit retainer plate to bracket (2), tighten
holding-down nuts alternately, and secure
idler adjuster assy.
Fixing idler adjuster assy
7. Compression of spring (5)

Remove spring pin (4), press spring (5)
lifting it with jack so that nut (3) can be
turned freely, and remove nut (3).
Compression of spring (5)
8. Removing bracket (2)

Allow the hydraulic jack to retract slowly
till the spring is extended to its free
length. Remove the retainer plate and take
off bracket (2), cover (10).
The free length of the spring: 320 mm
(12.6 in)
Removing retainer plate, bracket (2)
34-27
9. Removing spring (5), grease cylinder (1)

Hook lifting eye nut (W) to screw M36 X
P3 on grease cylinder (1) top end and
hoist it. Then, remove the set of grease
cylinder (1) and spring (5) using crane from
the jig.
Remove spring (5) and grease cylinder (1),
in that order.
Removing spring (5), grease cylinder (1)
34-28
(2) Assembly
Assembly is done in the reverse order of disassembly.
1. Installing spring (5), grease cylinder (1)

Insert grease cylinder (1) into spring (5)
and attach lifting eye nut (W) to screw M36
X P3 at the tip of the grease cylinder. Lift
the grease cylinder by crane and erect it in
the center of the jig stand upright. 34
2. Fixing idler adjuster assy
Install bracket (2), cover (10) on top of
spring (5). Center the rod of grease Attach spring (5) and grease cylinder (1) to
cylinder (1) and the holes in bracket (2). the jig
Attach the retainer plate and four
holding-down nuts. Fasten the nuts evenly
all round and fix the idler adjuster assy to
the jig body.
3. Compressing spring (5) and tightening nut

(3)
Extend the hydraulic jack, compress spring
(5) to a set length and screw in nut (3) to
the screwed part at the tip of grease
cylinder (1).
Set length of the spring: 270 mm (10.63 in)
4. Installing spring pin (4)
Tighten nut (3) till the holes for locking
spring pins (4) are aligned. Then fit spring
pin (4).
Compression of spring (5), and attaching nut
(3) and spring pin (4)
5. Removing idler adjuster assy

Remove idler adjuster assy from jig.
Removing idler adjuster assy
34-29
6. Installing oil seal (8), O-ring (7)

Fit oil seal (8) and O-ring (7) to grease
cylinder (1).
-Grease oil seal (8) and O-ring (7).
7. Filling grease cylinder(1) with grease.
Fill up grease in cylinder (1), remove the
grease nipple from piston (6) to discharge
the inside air, and press in the piston by
hand.
Grease cylinder (1)
-Direct grease nipple hole downward to
make air discharge easier.
8. Installing grease nipple
Tighten grease nipple to piston (6).
34.1.5.4.3 MAINTENANCE STANDARD
34-30
34.1.6 SPROCKET
34.1.6.1 REMOVING
Remove crawler referring to "34.1.2
CRAWLER", lift up crawler frame with
attachment, and put it on square timbers
to float and stabilize.
34
(2) Removing sprocket

Loosen 12 capscrews (3) M14, for the
attaching of the sprocket by means of a
socket and remove the sprocket (2).
Weight of sprocket: 29 kg (64 lbs)

Removing sprocket
34.1.6.2 INSTALLING
(1) Check before installing
Check the mating portion of the travel
reduction unit and the sprocket, eliminate
burrs and contamination thoroughly and
install the sprocket.
(2) Installing sprocket temporarily
Coat the sprocket attaching capscrews
with Loctite #262 and fasten the sprocket
temporarily.
(3) Installing sprocket completely
Remove the wooden blocks under the
truck frame, bring the machine down on the Installing sprocket completely
ground and tighten the sprocket.
34-31
34.1.6.3 MAINTENANCE STANDARD (2404N267)

PITCH 78.7mm (3.10in) NUMBER OF TEETH 21
SPECIFICATION
ROLLER DIA. Dia. 41mm (1.61in) PITCH DIA. 527.9 (20.78in)
Sprocket
34.1.6.4 SPROCKET TOOTH PROFILE GAUGE
Tooth profile gauge
34-32
34.1.7 TRAVEL MOTOR

34.1.7.1 TRAVEL MOTOR
34
Installing travel motor
34.1.7.2 REMOVING
Remove crawler, lift up crawler frame
using attachment, and put it on square
timbers to float and stabilize.
(2) Removing cover (1)
Remove capscrew (2) and also remove
covers (1).
(3) Preparation of oil pan
Removing and installing cover (1)
(4) Removing hydraulic pipe

Release pressure from travel circuit, and
bleed air in hydraulic oil tank, then remove
all pipes connecting to travel motor. Then
plug up all pipes and joint section to
protect them from entry of dust.
Tools: Spanner: 19 mm, 22 mm, 24 mm,
27 mm, 32 mm
Refer to "Hydraulic pipe plug" 4.1
(See Chapter 11. TOOLS) Removing and installing hydraulic pipe
34-33
(5) Removing sprocket

Removing 24 (one side) capscrews (3) M14
X 35.
Removing and installing sprocket
(6) Loosening travel motor attaching bolts (2)

Apply match marks on travel motor and
crawler frame, and remove 24 (one side)
capscrews (2) M16 X 40.
Removing and installing travel motor

attaching bolts
(7) Slinging travel motor assy

Sling travel motor with nylon sling applied
on the side close to sprocket installing
section and remove the motor.
Weight of motor: About. 90 kg (198 lbs)
Slinging travel motor
34-34
34.1.7.3 INSTALLING
Installing of the travel motor piping is performed in the reverse order of removal.
1. Cleaning
Check that contact surface of travel motor and crawler frame is free from burr and stain.
Tighten capscrew and hydraulic pipes to the torque specified in "Tightening Torque".
3. Fill inside from motor drain port to casing with hydraulic oil before piping for drain. When starting
operation, operate motor in low idling and at low speed for several minutes, and check it for 34
possible oil leakage and noise.
Tightening Torque
Parts Size Tools No. Remarks
N-m(lbf-ft)
Capscrew M14 22 3 181 (134) Apply loctite #262
M16 24 2 279 (210) Apply loctite #262
Flareless nut for ø10 X 1.5 19 - 49 (36)
pipes, sleeve ø15 X 2.0 27 - 118 (87)
ø18 X 2.5 32 - 147 (110)
Connector PF1/4 19 PP 36.3 (27)
PF3/8 22 T1,T2 73.6 (54)
PF1/2 27 P1,P2 108 (80)
34-35
34.1.8 SWING BEARING

34.1.8.1 SWING BEARING ASSY
Swing bearing assy
34.1.8.2 REMOVING
(1) Matchmarks
Remove upper structure, apply matchmarks
on inner race of swing bearing and lower
frame.
(2) Remove 30 capscrews (2) M16 X 85 for
installation inner race.
Matchmarks
(3) Removing grease

Remove grease in grease bath.
(4) Removing swing bearing
Attach eyebolt on swing bearing (1) and
sling it.
Weight of swing bearing: 100 kg (221 lbs)

Removing and installing swing bearing
34-36
34.1.8.3 INSTALLING
(1) Cleaning
Clean it completely so that installing
surfaces of swing bearing and lower frame
are free from dust and dirt.
(2) Installing
Install swing bearing on lower frame
meeting the matchmarks and positioning the
S mark on inner race as shown in the right 34
Fig..
(3) Temporary fastening of inner race
Coat the threads of the capscrews (2) with
Loctite #262 and tighten all the capscrews
(2) temporarily.
Tools: Socket: 24 mm Location of S mark on swing bearing
(4) Regular tightening of inner race

Tighten the capscrews (2) at 180 degrees
intervals alternately to a specified torque.
(5) Filling grease
Fill grease bath with 4.9 kg (11 lbs) of
grease NLGI-2 (molybdenum disulfide
Removing and installing capscrew (2)
grease) or equivalent.
Sectional view of swing bearing
34-37

(1) Disassembly
1. Remove seal (9) fitted in the groove in the
outer circumference under inner race (1)
and seal (8) fitted in the groove in the
inner circumference on top of outer race (2)
and place them level on a square wooden
block or something.
2. Remove taper pin (7), using a hammer and
an extrusion rod.
3. Remove plug (6), utilizing an pull bolt
inserted in the screwed hole in the center Disassembling swing bearing
of the plug and using a puller.
4. While rotating outer race (2) little by little,

take out ball (3) and retainer (4) through
plug hole, in that order.
Removing balls (3) and retainers (4)
(2) Installing
1. Thoroughly remove the grease from the
groove of the seal (8) located on the inner
surface of the outer race (2) and from the
groove of the seal (9) located on the
surface of the inner race (1).
Coat the grooves with adhesive Cyano
Bond P0-1 equivalent. fit seal (9) and place
it on a surface plate.
Fitting balls (3)
2. Lower outer race (2) to the position where

upper surface of inner race (1) and lower
portion of seal groove is mated, put
adjusting washer under outer race (2) so
that outer raceway surface of ball (3) aligns
with inner raceway, and support it.
3. Insert ball (3) and retainer (4), on which
grease is applied, through plug (6) hole on
outer race (2), alternately.
Fitting retainer (4)
34-38
To insert ball (3) and retainer (4), use a push rod, etc., to protect persons from injury from inserting
fingers into plug hole.
4. Fit plug (6) to outer race (2) while checking it for direction and position of taper pin hole.
5. Coat seal (8) with adhesive Cyano Bond P0-1 equivalent and fit it in the groove of outer race (2).
6. Check that grease nipple (10) is properly fitted, and fill it with grease. Then, check bearing for 34
smooth rotation and flaws on seal lip portion.

Maintenance standard concerning wear of swing bearing is described in the section 13.6 MEASURING
SWING PERFORMANCES of "Maintenance Standard and Test Procedure" in this manual.
34-39
34-40
34.2.1 TRAVEL MOTOR

(1) General view
34
HYDRAULIC CIRCUIT
34-41
(2) Structure of Travel unit
34-42
(3) Parts list

1 TRAVEL GEAR ASSY 1 14 SPRING 1
1-1 CASING B DY 1 15 SPRING 1
1-2 FLOATING SEAL 1 16 STEEL BALL 2
1-3 BALL BEARING 2 17 PIN 3
1-4 RING NUT 1 18 SNAP RING 1
1-5 CASING GEAR 1 19 SPRING PIN 1 34
1-6 SUN GEAR A 1 20 BRAKE PISTON 1
1-7 PLANETARY GEAR A 3 21 FRICTION PLATE 2
1-8 NEEDLE BEARING A 3 22 STEEL PLATE 2
1-9 CARRIER 1 23 SPRING 1
1-10 SUN GEAR B 1 24 PLATE 1
1-11 PLANETARY GEAR B 4 25 PLUG 2
1-12 BUSHING 4 26 POPPET 2
1-13 NEEDLE BEARING B 4 27 SPRING 2
1-17 THRUST PLATE 4 4 31 BACK UP RING 1
1-18 SCREW 8 32 O-RING 1
1-19 WASHER 1 33 BACK UP RING 1
1-20 PARALLEL PIN 1 34 O-RING 1
1-21 COVER 1 41 PIN 2
1-22 SPRING WASHER 12 42 BOLT 8
1-23 BOLT 12 43 MOTOR COVER 1
1-24 PLUG 2 44 SPOOL ASSY 1
1-25 O-RING 2 44-1 SPOOL (LL) 1
2 SHAFT 1 44-2 ORIFICE 2
3 CYLINDER BARREL 1 45 PUSHER 2
4 BALL RETAINER 1 46 SPRING 2
5 RETAINER 1 47 COVER 2
6 CAM 1 48 O-RING 2
7 PISTON ASSY 9 50 ORIFICE 1
7-1 PISTON 9 51 SPOOL 1
7-2 SLIPPER 9 56 ORIFICE 1
8 VALVE PLATE 1 57 STEEL BALL 2
9 PLATE 1 58 PLUG 2
10 PISTON ASSY 1 59 O-RING 4
10-1 PISTON 1 60 RELIEF VALVE ASSY 2
10-2 PUSHER 1 60-1 BODY 2
11 BALL BEARING 1 60-2 POPPET 2
12 BALL BEARING 1 60-3 ROD 2
13 OIL SEAL 1 60-4 SEAT 2
34-43

60-5 PISTON 2 63 PLUG 7
60-7 NUT CAP 2 65 PLUG 3
60-8 SPRING 2 67 NAME PLATE 1
60-11 O-RING 2 68 RIVET 2
60-12 O-RING 2 73 SPRING 1
60-13 O-RING 2 74 PLUG 2
60-15 BACK UP RING 2 75 O-RING 1
60-16 BACK UP RING 4 80 PLUG 1
61 PLUG 2 81 O-RING 1
62 O-RING 2
34-44
34.2.1.2 JIGS
(1) Jig for floating seal fitting
34
34-45
34.2.1.3 DISASSEMBLING
(1) Disassembling
1. Clean the outside surface of travel unit
prior to disassembly. Be sure to attach the
parts to the original positions.
For this purpose, we strongly recommend
to record the original positions of parts
before and during disassembling.
2. Remove the drain plug and drain lubricating
oil.
The travel unit oil capacity is 1.35L. Place
the travel unit on flat and clean ground.
3. Remove the relief valves (1) on both sides.
Remove the relief valve (1) first, and the removal of 8 bolts (2) and the motor cover (3) becomes
easier.
4. Loosen 8 bolts (2) and remove cover (3).
Be careful not to drop the valve plate.

Be careful not to damage the valve plate. Valve plate is located at the internal surface side of the
motor cover.
34-46
Raise the motor cover and insert 2 flat-blade screwdrivers in the space between the casing and the
body, and pry them slowly and the motor cover can be removed with relative ease.
(Do not damage the O-ring on the mating surface.)
5. Place the motor cover (3) on the wood

blocks (5). 34
6. Remove the backup rings (6) and O-rings

(7) from the relief valve (1).
7. Remove the cover (8) from the motor cover

(3) as shown by the right figure.
The strong spring force is applied to the cover (8). Loosen bolts gradually with care to ensure safe
and prevent the cover from damaging when removing.
34-47
8. Remove the spring (9), pusher (10), and

spool (11) from the motor cover. These
parts are located under the cover (8).
9. Remove the plug (12) from top of the

motor cover.
10. Remove the spring (13) and spool (14)

from the motor cover. These parts are
located under the plug (12).
11. Remove 2 plugs (15).
34-48
12. Remove the O-rings (16) from respective

plugs. And remove the steel balls (17) from
the motor cover.
34
13. Remove the plug (18) from the motor cover.
14. Remove the spring (19) and poppet (20)

from under the plug (18). Remove the
O-ring (21) from the plug (18).
15. Turn the motor cover over. And remove the

valve plate (22) from the motor cover.
34-49
16. Remove the bearing (23) if required.
17. Next, remove the 3 O-rings (24) (25) from

the casing body.
18. Remove the brake piston from the casing

body. The brake piston rises from the
casing body by the air blow from "A" port.
Be sure to cover the brake piston to prevent being injured by springing out of the brake piston in
blowing air in.
34-50
19. Remove the O-rings (27) (28) and the

backup rings (29) (30) from the brake
piston.
34
20. Using the steel wire or magnet, remove the

friction 2 plates (31) and 2 steel plates
from the body casing.
Do not remove the cylinder barrel yet.
34-51
21. Place the travel unit on the wood blocks as

shown by the photo. And block the unit to
prevent from rolling.
Remove the cylinder barrel assembly (33)
22. Make sure that reassemble the retainer

(34), piston assembly (35), and cylinder
barrel to the original position.
To avoid misassembling, record the
original positions of parts before
disassembling.
23. Remove the retainer (34) and piston
assembly (35) from the cylinder barrel
(36). And remove the piston assembly
from the retainer.
24. Remove the retainer ball (37) from the

cylinder barrel.
34-52
25. Remove 3 pins (38) from the cylinder barrel.
34
26. Using the suitable jig in diameter, compress

the plate (39) slightly with the press
machine. And remove the snap ring (40).
Then, remove the plate (39) and plate (42)
from the cylinder barrel.
The strong spring force is applied to the plate (39).
During disassembling the cylinder barrel, use a press machine and hold the spring in compressed state
to ensure the safety and to prevent the parts damage.
34-53
27. Remove the cam (43) from the body casing.
28. Remove the 2 steel balls (44) and piston

(45) from the body casing. And remove
the spring (46) which is located under the
piston.
34-54
29. Place the travel motor unit on the wood

blocks.
To avoid the damage of X shaft, do not
place the travel motor unit on a flat board
directly, and place the unit on the wood
blocks surely. Remove 12 bolts (47) and 12
washers (48).
34
30. Using a soft head hammer, tap and

loosen the sealant between the cover (49)
and gear casing (50).
And remove the cover (49).
34-55
31. Remove 3 bolts (51) and the thrust plate

(52).
32. Remove the sun gear (53), 3 planetary

gears (54), and 3 bearings (55).
33. Remove the carrier (56).
34-56
34. Remove the 3 inner races from the shaft of

carrier, if required.
34
35. Remove the sun gear (58).
36. Remove 4 bolts (59) and the thrust plate

(60).
34-57
37. Remove each of 4 planetary gears (61),

bearings (62), bushings (63), and plates
(64).
38. Remove the bolt (65) and the washer (66).
39. Using a magnet, remove the pin (67). If it

is difficult to remove, follow the next
procedures.
a.
Apply an adhesive tape or a magnet plate
to cover the thread hole as shown by the
photo.
b.
Drill a hole in the pin (67).
c.
Do the tapping work in the drilled hole of
the pin (67).
d.
Screw a suitable bolt in the thread hole,
and lift up the pin.
40. Remove the ring nut (68) from the body
34-58
casing.
41. Using a crane, remove the gear casing (50)

34
42. Remove one of the angular bearings (69)

from the gear casing.
43. Turn the gear casing over. Remove the

floating seal (72) and the other angular
bearings (69) from the gear casing.
44. Remove another floating seal (72) from the

body casing (73).
To remove them from the body casing,
strike the shaft (74) and the bearing (75)
with plastic hammer and suitable jig in
direction shown in the figure.
34-59
45. Remove the bearing (75) from the body

casing, if required.
And remove the oil seal (76) from the body
casing.
46. Remove the bearing (75) from the shaft

(74), if required.
This completes disassembly.
34-60
(2) Assembling
1. Be sure to check that all parts are clean and free from earth and dirt.
Check all O-ring, backup ring and oil seal fitted on travel unit for poor condition. When any
defect was found, replace it with new one.
Install the new floating seal.
Place the body casing on clean sheet spread on flat ground.
2. Install the oil seal in the body casing.

And install the bearing (75) on the shaft 34
(74).
Then, install the shaft (74) in the body
casing.
3. Place body casing on wooden block or

suitable jig directing the shaft side
downward.
Do not place the body casing directly on
flat surface to prevent shaft from damaging.
4. Using the "Jig for floating seal fitting",

install the floating seal (72) in the body
casing.
34-61
Clean and dry O-ring (rubber) and seal ring (metal) before attaching the floating seal.
Apply SAE30 engine oil or gear oil 80W-90 to the contact surface of the seal ring.
5. Apply SAE30 engine oil or gear oil

80W-90 to the contact surface (flat
surface) of the seal ring (metal).
6. Install the angular bearing (69) in the gear

casing.
7. Turn the gear casing over as shown by the

photo. Install the other angular bearings
(71) in the gear casing.
34-62
8. Using the "Jig for floating seal fitting",

install the other floating seal (70) in the
body casing. Apply SAE30 engine oil or
gear oil 80W-90 to the contact surface
(flat surface) of the seal ring (metal).
34
-Clean and dry O-ring (rubber) and seal ring (metal) before attaching the floating seal.
Apply SAE30 engine oil or gear oil 80W-90 to the contact surface of the seal ring.
-When joining 2 parts, use caution to prevent damage like scratch and so on to the floating seal.
9. Lift the gear casing (50) on the body

casing (73) by means of a crane as
shown in the figure. Install the gear casing
to the body casing (73).
With the ring gear placed on the body casing, there is a space left between them. This space is not a
problem because it is caused by the action of a floating seal. This space is eliminated by attaching
ring nut (68).
34-63
10. According to the following procedure,

adjust the precompression between the
bearings (69) and (71).
a.
To avoid narrow gap among the body
casing, 2 bearings, the gear casing, and
the ring nut, tighten the ring nut (68) tightly.
b.
Rotate the gear casing (50) several turn.
c.
Pull the ring nut in tangential direction with
the weight scale as shown by the photo,
and adjust the position of the ring nut
(68). During tightening or loosening of the
ring nut, the scale reading should be
adjusted within the range from 100N to
135N (22.5 lb~30.4 lb).
11. Apply an adhesive tape or a magnet plate

to cover the thread hole. Drill the new
hole at middle position between the body
casing and the ring nut as shown by the
photo.
Specification of the hole:
Hole diameter: 6.00 to 6.15 mm
(ø0.236"~ø0.242") in diameter
Hole depth: 7.0 to 7.5 mm (0.276"~0.295")
in depth
When attaching the pin (67) to the ring nut (68), new hole must be drilled on the opposite side of
the original hole. Because the ring nut position is not always the same after adjustment performed by
the procedure 10).
12. Remove the all drilling chips.

Install the pin (67) into the new hole
which is drilled at middle position between
the body casing (73) and the ring nut (68).
34-64
13. Apply the sealant "Three Bond #2403" to

the bolt (65). Install the bolt (65) and the
washer (66) in the casing. Tighten the bolt
to the specified torque 35.3±2.0 N-m
(26±1.5 lbf-ft).
34
14. Place the travel unit as shown by the

photo. Install the 2 steel balls (44), spring
(46), and piston (60) in the body casing.
15. Install the cam (43) into the body of the

travel unit. Push the cam several times,
and check that the motion is smooth.
16. Install the plate (42), the spring (41), and

the plate (39) in the cylinder barrel.
34-65
17. Using the press machine, push the plate

(39) to compress the spring (41). And
install the snap ring (40).
18. Install 3 pins (38) in the cylinder barrel.
19. Install the retainer ball (37) in the cylinder

barrel.
Apply clean hydraulic oil to the retainer ball
(37).
20. Install the piston assembly (35) in the

respective original holes of the retainer (34).
Apply clean hydraulic oil to the hole of
cylinder barrel and the piston assembly (35).
Install the assembly of retainers and pistons
into the original positions in the original
combinations.
34-66
21. Apply clean hydraulic oil to the cam, the

sliding surface of 9 piston shoes, and the
spline of motor shaft.
Then, lay the travel unit down, and install
the integrated cylinder barrel assembly (33)
into the shaft.
34
22. Apply the clean hydraulic oil to 2 friction

plates and 2 steel plates (32).
23. Install these plates in the body of travel

unit alternately. The innermost plate is the
friction plate, and the nearest plate is steel
plate.
24. Check that brake piston (26) is clean and

is free from earth and dirt. Check the
backup rings (29) (30) and O-rings (27)
(28) for possible damage. When any
irregularity or damage was detected, replace
it with new one.
Fit the backup rings (29) (30) and O-rings
(27) (28) as shown in the figure.
Apply a small amount of grease to the
backup rings and O-rings.
Be careful about the fitting positions of the
O-rings and the backup rings. (See figures)
34-67
25. Apply clean hydraulic oil to the sliding

surface of brake piston (26) of the body
casing. Using a soft head hammer, install
the brake piston (26) in to the travel unit
body.
26. Install 3 O-rings (24) (25) into the casing

body.
27. Install the bearing (23) into the motor cover.
28. Turn the motor cover over, and place it on

the wood blocks.
34-68
29. Install the spring (19) and the poppet (20)

into the motor cover. Install the O-ring (21)
in the plug (18).
34
30. Tighten the plug (18) to the specified

torque 65.7 N-m (48.5 lbf-ft).
31. Install the O-rings (16) in 2 plugs (15).

Put the steel ball (17) in the motor cover.

torque 19.6±1.0 N-m (14.5±0.7 lbf-ft).
34-69
33. Install the spring (13) and spool (14) in

the motor cover.

35. Apply the appropriate amount of hydraulic

oil to the spool (11), and install it in the
motor cover.
36. Tighten the cover (8) to the specified

torque 176.4 N-m (130 lbf-ft).
34-70
37. Turn the motor cover over. Install the

valve plate (22) in the original position.
Apply the appropriate amount of hydraulic
oil to the surface of the valve.
34
38. Apply grease to the 10 holes of the motor

cover. Install the springs (76) into the holes.
To prevent the springs (76) from falling
from holes, the grease was applied.
39. Place the motor cover (3) on the body

casing. Check if the springs (76) are not
fallen.
Tighten 8 bolts (2) to install the motor
cover.
Tighten the bolts (2) to the specified
40. Install the backup ring (6) and O-ring (7)

into the relief valve (1).
34-71
41. Tighten the relief valve (1) to the specified

42. Place the travel unit with directing the

brake side downwards as shown by the
photo. Apply the torque load to the shaft
(74), and check the value of the parking
brake torque. At the start of the rotation,
the torque should be 239 N-m (176.3
lbf-ft) or more.
43. Install each four of plates (649, bushings

(63), bearings (62), and planetary gears
(61).
44. Install the thrust plate (60) as shown by

the photo. Apply the sealant "Three Bond
#2403" to the bolt (59), and tighten 4
bolts (59). Tighten the bolts to the specified
torque 35.3±2.0 N-m (26±1.5 lbf-ft).
Next, install the sun gear (58).
34-72
45. Install 3 inner races (57) in the shaft of the

carrier (56).
34
46. Install the carrier (56) as shown by the

photo.
47. Install 3 bearings (55) and 3 planetary

gears (54) into the carrier (Inner race was
installed already).
Next, install the sun gear (53).
48. Install the thrust plate (52) in the carrier.

Apply the sealant "Three Bond #2403" to
the bolt (51), and tighten 3 bolts (51), and
install the plate (52) in the carrier. Tighten
the bolts to the specified torque 35.3±2.0
N-m (26±1.5 lbf-ft).
34-73
49. Check that the machined surfaces of the

gear casing (59) and the cover (49) are
clean, are free from earth and dirt and are
dried. Apply "Three Bond #1389" to the
machined surface of gear casing as shown
in the figure.
50. Attach the cover (49) to the original position

with 12 bolts (47) and 12 washers (48).
Tighten bolts to the specified torque
13.7±1.0 N-m (10.1±0.7 lbf-ft).
Fill lube oil from drain port. The optimum
oil quantity for the reduction gear is 1.35L.
Attach 2 drain plugs (77).
Fill the case of motor with hydraulic oil to prevent damage of the motor before starting operation.
34-74
［46. TROUBLE SHOOTING (BY ERROR CODES)］
46. TROUBLE SHOOTING

(BY ERROR CODES)
TABLE OF CONTENTS
46.1 JUDGMENT OF ACTUAL THING AT SITE ………………………………………………………………46-3

46.2 CLASSIFICATION OF FAILURE AND TROUBLESHOOTING …………………………………………46-4
46.3 THE BLOWN FUSE OF MECHATRO CONTROLLER ……………………………………………………46-5
46.4 TROUBLESHOOTING BY ERROR CODE …………………………………………………………………46-6
46
46-1

S5YT4609E01
First Edition June, 2010 E70BSR : YT06-18001~
(NHK-EUR)
E80BMSR : LF06-04501~
(NHK)
SK80CS-2 : LF06-04501~
(NA)
SK70SR-2 : YT06-18001~
(NA)
October, 2010 SK70SR-2 : YT06-18444~

(AUS)
Preface
Troubleshooting provides process locating for
the cause of trouble in the order that trouble
occurred. This manual describes how to solve
the specific phenomenon systematically as
early as possible. For troubleshooting
concerning the inside of equipment, refer to
troubleshooting for each manual of equipment.
Attending the field to verify actual thing.
46-2
46.1 JUDGMENT OF ACTUAL THING AT SITE
(1) Get to the site as quickly as possible.

Verify model, serial number, situation of trouble
and field, and notify person of arrival time.
(2) Verify background of trouble occurred
1. Model name and serial number
2.
Kind of attachment
Check that the combination of attachment is
proper or that the operating method is not
unreasonable.
3. Operating time by hour-meter
Verifying background of trouble occurred.
4.
History of trouble occurred and additional works.
5.
Recurrence of past trouble, or problems on the
additional works.
(3) How to diagnose trouble

1. Verify defective part
2. Make the condition of trouble again
3.
Where defective parts can not be verified,
surmise causes systematically.
4. Verify reasons for surmise
5.
Report methods, procedure, and period for
repairing to user.
Confirm the symptoms of the trouble. 46
(4) Explanation of the cause of trouble

1.
Explain the cause of trouble to clients. For
example, oil leak through piston is caused by
flaws on the piston rod. And the method of
using the machines should be explained so that
the same kind of trouble does not reoccur. Diagnosing fail by means troubleshooting.
2.
Treatment of damaged parts
The damaged parts to be claimed and
returned are evidence so they should be
handled with care. Protect them from entry of
water, soils, etc. into port of hydraulic unit, etc.
and return them. And also use care not to
flaw and damage those surfaces.
46-3
46.2 CLASSIFICATION OF FAILURE AND TROUBLESHOOTING
Classify failures into the following 3 types and carry out the troubleshooting.
No. Classes of failure Troubleshooting

A When error code after self-diagnosis is displayed Carry out troubleshooting according to the error code.
on gauge cluster
B When no failure is detected currently but error When it is hard to recreate the failure situation,
code after self diagnosis is remained in trouble cancel the data in the history and reproduce the
history failed situation or suppose the cause according to
the troubleshooting by error code, and then repair it.
C When error code after self diagnosis is not -Carry out troubleshooting according to instructions in
displayed or is not remained in the history Chapter 47 "TROUBLESHOOTING BY TROUBLE".
46-4
46.3 THE BLOWN FUSE OF MECHATRO CONTROLLER
If the fuse of mechatro controller has blown, the following display appears on the gauge cluster.
(1) The blown fuse of mechatro controller
a. Blown fuse 5A of mechatro controller :

"DATA COMMUNICATION ERROR" is displayed on the gauge cluster in the condition where the
controller program is not executed.
b. Blown fuse 20A of mechatro controller
The controller functions normally but the power supply applied when the controller drives the
solenoid, etc. stops.
Many error codes are displayed on the gauge cluster.
F021, F031
46
46-5
46.4 TROUBLESHOOTING BY ERROR CODE
When error code was displayed on the gauge cluster with the aid of self-diagnosis display function,
carry out the troubleshooting referring to applicable page in the contents of error codes.
Error Code Trouble

A015 Engine adjustment (A adjustment) is not adjusted yet or is failed.
A215 Written data of ROM adjustment data is incorrect.
A225 Writing of ROM adjustment data is incorrect.
A235 Written data of ROM hour meter data is incorrect.
A245 Writing of ROM hour meter data is incorrect.
A255 Writing of proportional valve adjustment data is incorrect.
B012 Incorrect output of boom up pressure sensor
B013 Disconnection of boom up pressure sensor
B014 Short-circuit of boom up pressure sensor
B022 Incorrect output of boom down pressure sensor
B023 Disconnection of boom down pressure sensor
B024 Short-circuit of boom down pressure sensor
B032 Incorrect output of arm out pressure sensor
B033 Disconnection of arm out pressure sensor
B034 Short-circuit of arm out pressure sensor
B042 Incorrect output of arm in pressure sensor
B043 Disconnection of arm in pressure sensor
B044 Short-circuit of arm in pressure sensor
B052 Incorrect output of bucket digging pressure sensor
B053 Disconnection of bucket digging pressure sensor
B054 Short-circuit of bucket digging pressure sensor
B062 Incorrect output of bucket dump pressure sensor
B063 Disconnection of bucket dump pressure sensor
B064 Short-circuit of bucket dump pressure sensor
B072 Incorrect output of swing pressure sensor
B073 Disconnection of swing pressure sensor
B074 Short-circuit of swing pressure sensor
B082 Incorrect output of swing left pressure sensor
B083 Disconnection of swing left pressure sensor
B084 Short-circuit of swing left pressure sensor
B092 Incorrect output of travel right pressure sensor
B093 Disconnection of travel right pressure sensor
B094 Short-circuit of travel right pressure sensor
B102 Incorrect output of travel left pressure sensor
B103 Disconnection of travel left pressure sensor
B104 Short-circuit of travel left pressure sensor
46-6
Error Code Trouble

C033 Disconnection of boom head pressure sensor
C034 Short-circuit of boom head pressure sensor
F021 Failure of output transistor OFF and GND short of swing parking SOL valve
F023 Failure of output transistor ON and disconnection of swing parking SOL valve
F031 Failure of output transistor OFF and GND short of travel 1-2 speed SOL valve
F033 Failure of output transistor ON and disconnection of travel 1-2 speed SOL valve
G032 Overrun of speed sensor of direct input Mechatro-controller
G033 Disconnection of speed sensor of direct input Mechatro-controller
H013 Disconnection of acceleration potentio
H014 Power short-circuit of acceleration potentio
H081 Short-circuit of coolant temperature ground sensor
H091 Failure of GND short-circuit of fuel sensor
H093 Disconnection of fuel sensor
I313 Received error of cluster communication (time-out error)
K014 Adhesion of battery relay terminal
R014 Failure of arc prevention relay of wiper motor
R024 Failure of normal rotation relay of wiper motor
R034 Failure of reverse rotation relay of wiper motor
R044 Failure of washer motor relay
R134 Failure of swing right flasher relay
R144 Failure of swing left flasher relay
R154 Failure of travel alarm relay
R164 Failure of auto idling stop relay 2
R174 Failure of engine forcible stop relay
R184 Failure of lever lock relay
46
46-7
Table 46-1
Error code A015
Trouble Not yet adjusted engine or failed adjustment of engine (A adjustment)
Judging Engine adjustment is missed. Or it is impossible to set the adjusting value within the adjusting
condition range.
Symptom Deviated from the reqired value, but no problem in normal operations.
Control in the
Rotate with the default engine
event of failure
Returned in
The engine adjustment is completed normally.
normal condition
Service Screen No. 2 G-3 SPEED SET

diagnosis Screen No.
checking screen Screen No.
Checking object Checking contents and remedy
1 -Checking Carry out engine adjustment (A adjustment). When "ERROR ENG" was
displayed during adjustment, refer to the section "Adjustment procedure -
Measures to be taken with the adjustment failed"
2 -Mechatro controller Check that the error is corrected after replacement of controller.
3
Table 46-2
Error code A215
Trouble The data of ROM adjustment is written incorrectly.
Judging Check adjustment data, and judge the content of memory is correct or not. (Trouble history
condition only)
Symptom No affect.
Control in the
Control at side of correct memory data.
event of failure
Returned in
It does not regain. Replace controller.
normal condition
Service Screen No.

1 Mechatro controller Check that the error is corrected after replacement of controller.
2
3
46-8
Table 46-3
Error code A225
Trouble The data of ROM adjustment is written incorrectly.
Judging
Check adjustment data, and judge the data is correct or not.
condition
Symptom It is not normal output, but no problem in normal operation
Control in the
Control can be done by default value.
event of failure
Returned in
normal condition
Service Screen No.

2
3
Table 46-4
Error code A235
Trouble The data of ROM hourmeter is written incorrectly.
Judging
Check hourmeter memory, and judge the data is correct or not. (Trouble history only)
condition
Symptom No affect.
Control in the
Control at side of correct memory data.
event of failure
Returned in
normal condition
Service Screen No. 46

2
3
46-9
Table 46-5
Error code A245
Trouble The data of ROM hourmeter is written incorrectly.
Judging
Check hourmeter memory, and judge the data is incorrect.
condition
Symptom The hour meter data which was judged as error is taken as 0 Hr. No problem in normal
operation
Control in the
Normal control is available.
event of failure
Returned in
normal condition
Service Screen No.

2
3
Table 46-6
Error code A255
Trouble The data of proportional valve adjustment is written incorrectly.
Judging
Check proportional valve adjustment data, and judge the data is incorrect.
condition
Symptom It is not normal output, but no problem in normal operation
Control in the
Using fixed value of proportional valve correction data, usual control is done.
event of failure
Returned in
normal condition
Service Screen No.

2
3
46-10
Table 46-7
Error code B012
Trouble Boom up pressure sensor outputs error
Judging After starter switch ON and engine does not start yet. And the input voltage from the sensor
condition after starter switch ON is in the range of 1.4V or more to less than 4.7V.
Symptom In case that auto acceleration is turned ON, even when control lever was shifted to neutral,
engine speed does not slow down.
Control in the
Normal control
event of failure
Returned in Not returned automatically under normal condition. Switch the power OFF once and turns on
normal condition it again.
Service Screen No. 5 B-1 BOOM RAISE

1 -Boom up pressure sensor When B012 is cancelled and other error occurs by turning starter switch
SE-3 on after exchanging the connector with other sensor.
Check sensor unit for possible failure. If failure found, replace it.
2 -Wiring between boom up When B012 is displayed after turning the starter switch on after the
pressure sensor and controller connector is exchanged with other sensor.
CN-126F Check wiring for possible failure according to the wiring checking
CN-101F procedure and repair it if necessary.
Table 46-8
Error code B013
Trouble Boom up pressure sensor's wiring disconnects.
Judging
The input voltage from boom up pressure sensor is less than 0.1V.
condition
Symptom In case that auto acceleration is turned ON, even when control lever was shifted to neutral, 46
Control in the
Normal control
event of failure
Returned in
It returns automatically in normal condition.
normal condition

1 -Boom up pressure sensor When B013 is cancelled and other error occurs after exchanging the
SE-3 connector with other sensor.
2 -Wiring between boom up When B013 is displayed after the connector is exchanged with other
pressure sensor and controller sensor.
46-11
Table 46-9
Error code B014
Trouble Boom up pressure sensor's power source is shortcut.
Judging
The input voltage from boom up pressure sensor is 4.7V or more.
condition
Control in the
Normal control
event of failure
Returned in
normal condition

1 -Boom up pressure sensor When B014 is cancelled and other error occurs after exchanging the
2 -Wiring between boom up When B014 is displayed after the connector is exchanged with other
Table 46-10
Error code B022
Trouble Boom down pressure sensor outputs error
Control in the
Normal control
event of failure
Service Screen No. 5 B-2 BOOM LOWER

1 -Boom down pressure sensor When B022 is cancelled and other error occurs by turning starter switch
2 -Wiring between boom down When B022 is displayed after turning the starter switch on after the
46-12
Table 46-11
Error code B023
Trouble Boom down pressure sensor's wiring is disconnecting.
Judging
The input voltage from boom down pressure sensor is 0.1V or less.
condition
Symptom In case that auto acceleration is turned ON, even when control lever was shifted, engine
speed dose not rise.
Control in the
Normal control
event of failure
Returned in
normal condition

1 -Boom down pressure sensor When B023 is cancelled and other error occurs after exchanging the
2 -Wiring between boom down When B023 is displayed after the connector is exchanged with other
Table 46-12
Error code B024
Trouble Boom down pressure sensor's power source is shortcut.
Judging
The input voltage from boom down pressure sensor is 4.7V or more.
condition
Symptom In case that auto acceleration is turned ON, even when control lever was shifted, engine 46
Control in the
Normal control
event of failure
Returned in
normal condition

1 -Boom down pressure sensor When B024 is cancelled and other error occurs by turning starter switch
2 -Wiring between boom down When B024 is displayed after turning the starter switch on after the
46-13
Table 46-13
Error code B032
Trouble Arm-in pressure sensor outputs error
Control in the
Normal control
event of failure
Service Screen No. 5 B-3 ARM OUT

1 -Arm-out pressure sensor When B032 is cancelled and other error occurs by turning starter switch
2 -Wiring between arm-out When B032 is displayed after turning the starter switch on after the
Table 46-14
Error code B033
Trouble Arm-out pressure sensor's wiring is disconnecting.
Judging
The input voltage from arm-out pressure sensor is 0.1V or less.
condition
Control in the
Normal control
event of failure
Returned in
normal condition

1 -Arm-out pressure sensor When B033 is cancelled and other error occurs after exchanging the
2 -Wiring between arm-out When B033 is displayed after the connector is exchanged with other
46-14
Table 46-15
Error code B034
Trouble Arm-out pressure sensor's power source is shortcut.
Judging
The input voltage from arm-out pressure sensor is 4.7V or more.
condition
Control in the
Normal control
event of failure
Returned in
normal condition

1 -Arm-out pressure sensor When B034 is cancelled and other error occurs by turning starter switch
2 -Wiring between arm-out When B034 is displayed after turning the starter switch on after the
Table 46-16
Error code B042
Trouble Arm-in pressure sensor outputs error
Judging After starter switch ON and engine does not start yet. And the input voltage from the arm-in
condition pressure sensor after starter switch ON is in the range of 1.4V or more to less than 4.7V.
Symptom Swing parking brake cannot be released during arm-in. 46
Control in the
The arm-in pressure is controlled to 0 MPa.
event of failure
Service Screen No. 5 B-4 ARM IN

1 -Arm-in pressure sensor When B042 is cancelled and other error occurs by turning starter switch
2 -Wiring between arm-in When B042 is displayed after turning the starter switch on after the
46-15
Table 46-17
Error code B043
Trouble Arm-in pressure sensor's wiring is disconnecting.
Judging
The input voltage from arm-in pressure sensor is 0.1V or less.
condition
Symptom Swing parking brake cannot be released during arm-in.
Control in the
event of failure
Returned in
normal condition

1 -Arm-in pressure sensor When B043 is cancelled and other error occurs after exchanging the
2 -Wiring between arm-in When B043 is displayed after the connector is exchanged with other
Table 46-18
Error code B044
Trouble Arm-in pressure sensor's power source is shortcut.
Judging
The input voltage from arm-in pressure sensor is 4.7V or more.
condition
Symptom Swing parking brake cannot be released during arm-in.
Control in the
event of failure
Returned in
normal condition

1 -Arm-in pressure sensor When B044 is cancelled and other error occurs by turning starter switch
2 -Wiring between arm-in When B044 is displayed after turning the starter switch on after the
46-16
Table 46-19
Error code B052
Trouble Bucket digging pressure sensor outputs error
Judging After starter switch ON and engine does not start yet. And the input voltage from the bucket
condition digging pressure sensor after starter switch ON is in the range of 1.4V or more to less than
4.7V.
Control in the
Normal control
event of failure
Service Screen No. 5 B-5 BUCKET DIG

1 -Bucket digging pressure When B052 is cancelled and other error occurs by turning starter switch
sensor on after exchanging the connector with other sensor.
SE-1 Check sensor unit for possible failure. If failure found, replace it.
2 -Wiring between bucket digging When B052 is displayed after turning the starter switch on after the
Table 46-20
Error code B053
Trouble Bucket digging pressure sensor's wiring is disconnected.
Judging
The input voltage from bucket digging pressure sensor is 0.1V or less.
condition 46
speed does not rise.
Control in the
Normal control
event of failure
Returned in
normal condition

46-17
Table 46-21
Error code B054
Trouble Bucket digging pressure sensor's power source is shortcut.
Judging
The input voltage from bucket digging pressure sensor is 4.7V or more.
condition
Control in the
Normal control
event of failure
Returned in
normal condition

Table 46-22
Error code B062
Trouble Bucket dump pressure sensor outputs error
Judging After starter switch ON and engine does not start yet. And the input voltage from the bucket
condition dump pressure sensor after starter switch ON is in the range of 1.4V or more to less than
4.7V.
Control in the
Normal control
event of failure
Service Screen No. 5 B-6 BUCKET DUMP

1 -Bucket dump pressure sensor When B062 is cancelled and other error occurs by turning starter switch
2 -Wiring between bucket dump When B062 is displayed after turning the starter switch on after the
46-18
Table 46-23
Error code B063
Trouble Bucket dump pressure sensor's wiring is disconnected.
Judging
The input voltage from bucket dump pressure sensor is 0.1V or less.
condition
Control in the
Normal control
event of failure
Returned in
normal condition

Table 46-24
Error code B064
Trouble Bucket dump pressure sensor's power source is shortcut.
Judging
The input voltage from bucket dump pressure sensor is 4.7V or more.
condition
Symptom In case that auto acceleration is turned ON, even when control lever was shifted, engine 46
Control in the
Normal control
event of failure
Returned in
normal condition

46-19
Table 46-25
Error code B072
Trouble Swing right pressure sensor outputs error
Judging After starter switch ON and engine does not start yet. And the input voltage from the swing
condition pressure sensor after starter switch ON is in the range of 1.4V or more to less than 4.7V.
Symptom Swing parking brake does not work.
Control in the
Swing parking solenoid valve is changed to non-excitation.
event of failure
B-7 SWING
Service Screen No. 6 (Higher Pressure is selected between swing left and right, and the
diagnosis higher one is indicated.)
Screen No.
1 -Swing right pressure sensor When B072 is cancelled and other error occurs by turning starter switch
2 -Wiring between swing right When B072 is displayed after turning the starter switch on after the
46-20
Table 46-26
Error code B073
Trouble Swing right pressure sensor's wiring is disconnected.
Judging
The input voltage from swing pressure sensor is 0.1V or less.
condition
Control in the
event of failure
Returned in
normal condition
B-7 SWING
Service Screen No. 6 (Higher Pressure is selected between swing left and right, and the higher
diagnosis one is indicated.)
Screen No.
46
46-21
Table 46-27
Error code B074
Trouble Swing pressure sensor's power source is shortcut.
Judging
The input voltage from swing pressure sensor is 4.7V or more.
condition
Control in the
event of failure
Returned in
normal condition
B-7 SWING
Screen No.
46-22
Table 46-28
Error code B082
Trouble Swing left pressure sensor outputs error
Judging After starter switch ON and engine does not start yet. And the input voltage from the swing
condition left pressure sensor after starter switch ON is in the range of 1.4V or more to less than 4.7V.
Control in the
event of failure
B-7 SWING
Screen No.
1 -Swing pressure sensor When B082 is cancelled and other error occurs by turning starter switch
2 -Wiring between swing When B082 is displayed after turning the starter switch on after the
46
46-23
Table 46-29
Error code B083
Trouble Swing left pressure sensor's wiring is disconnected.
Judging
The input voltage from swing left pressure sensor is 0.1V or less.
condition
Control in the
event of failure
Returned in
normal condition
B-7 SWING
Screen No.
46-24
Table 46-30
Error code B084
Trouble Swing left pressure sensor's power source is shortcut.
Judging
The input voltage from bucket dump pressure sensor is 4.7V or more.
condition
Control in the
event of failure
Returned in
normal condition
B-7 SWING
Screen No.
Table 46-31
Error code B092
Trouble Travel right pressure sensor outputs error
Judging After starter switch ON and engine does not start yet. And the input voltage from the travel
condition right pressure sensor after starter switch ON is in the range of 1.4V or more to less than 46
4.7V.
Symptom Engine speed of high idling at H mode rises to 2400 rpm.
Control in the
During parking, the 2200 rpm limitation of engine speed is not done.
event of failure
Service Screen No. 6 B-9 TRAVEL (R)

1 -Travel right pressure sensor When B092 is cancelled and other error occurs by turning starter switch
2 -Wiring between travel right When B092 is displayed after turning the starter switch on after the
46-25
Table 46-32
Error code B093
Trouble Travel right pressure sensor's wiring is disconnected.
Judging
The input voltage from Travel right pressure sensor is 0.1V or less.
condition
Control in the
event of failure
Returned in
normal condition

Table 46-33
Error code B094
Trouble Travel right pressure sensor's power source is shortcut.
Judging
The input voltage from Travel right pressure sensor is 4.7V or more.
condition
Control in the
event of failure
Returned in
normal condition

46-26
Table 46-34
Error code B102
Trouble Travel left pressure sensor outputs error
Judging After starter switch ON and engine does not start yet. And the input voltage from the travel
condition left pressure sensor after starter switch ON is in the range of 1.4V or more to less than 4.7V.
Control in the
event of failure
Service Screen No. 6 B-10 TRAVEL (L)

1 -Travel left pressure sensor When B102 is cancelled and other error occurs by turning starter switch
2 -Wiring between travel left When B102 is displayed after turning the starter switch on after the
Table 46-35
Error code B103
Trouble Travel left pressure sensor's wiring is disconnected.
Judging
The input voltage from Travel left pressure sensor is 0.1V or less.
condition
Control in the
46
event of failure
Returned in
normal condition

46-27
Table 46-36
Error code B104
Trouble Travel left pressure sensor's power source is shortcut.
Judging
The input voltage from Travel left pressure sensor is 4.7V or more.
condition
Control in the
event of failure
Returned in
normal condition

Table 46-37
Error code C033
Trouble Boom head pressure sensor's wiring is disconnected.
Judging
The input voltage from boom head pressure sensor is 0.1V or less.
condition
Symptom Over load alarm function does not actuate.
Control in the
Normal control
event of failure
Returned in
normal condition
Service Screen No. 7 C-3 BOOM-HEAD

1 -Boom head pressure sensor When C033 is cancelled and other error occurs by turning starter switch
2 -Wiring between boom head When C033 is displayed after turning the starter switch on after the
46-28
Table 46-38
Error code C034
Trouble Boom head pressure sensor's power source is shortcut.
Judging
The input voltage from boom head pressure sensor is 4.7V or more.
condition
Symptom Over load alarm function does not actuate.
Control in the
Normal control
event of failure
Returned in
normal condition
Service Screen No. 7 C-3 BOOM-HEAD

1 -Boom head pressure sensor When C034 is cancelled and other error occurs by turning starter switch
2 -Wiring between boom head When C034 is displayed after turning the starter switch on after the
Table 46-39
Error code F021
Trouble Swing parking solenoid valve and output transistor OFF are failure, and grounding is
short-circuit.
Judging
The feed-back signal is grounding level while exciting command is output.
condition
Symptom Swing parking is not available. 46
Control in the
Normal control
event of failure
Returned in
The feed-back signal is 24V level while exciting command is output.
normal condition
Service Screen No. 3 F-2 SWING-BRAKE

1 -Swing parking solenoid valve When F021 is cancelled and other error occurs by exchanging the
SV-1 connector for other solenoid valve. Check solenoid valve unit for
possible failure. If failure found, replace it.
Check solenoid valve unit for possible failure. If failure found, replace it.
2 -Wiring between swing parking When F021 is displayed after the connector is exchanged with other
solenoid valve and controller solenoid valve.
46-29
Table 46-40
Error code F023
Trouble Swing parking solenoid valve and output transistor ON are failure, and disconnection.
Judging
The feed-back signal is 24V level while exciting command is not output.
condition
Symptom Swing parking is not available or is leaving available.
Control in the
Normal control
event of failure
Returned in
The feed-back signal is grounding level while exciting command is output.
normal condition
Service Screen No. 3 F-1 POWER BOOST

1 -Swing parking solenoid valve When F023 is cancelled and other error occurs by exchanging the
SV-1 connector for other solenoid valve.
2 -Wiring between swing parking When F023 is displayed after the connector is exchanged with other
Table 46-41
Error code F031
Trouble Travel 1, 2 speed solenoid valve and output transistor OFF are failure, and grounding is
short-circuit.
Judging condition The feed-back signal is grounding level while exciting command is output.
Symptom Travel 2 speed is not obtainable.
Control in the
Normal control
event of failure
Returned in
The feed-back signal is 24V level while exciting command is output.
normal condition
Screen No. 3 F-3 1/2-TRAVEL
Service diagnosis
Screen No.
checking screen
Screen No.
1 -Travel 1, 2speed solenoid valve When F031 is cancelled and other error occurs by exchanging the
2 -Wiring between travel 1, 2speed When F031 is displayed after the connector is exchanged with other
46-30
Table 46-42
Error code F033
Trouble Travel 1, 2 speed solenoid valve and output transistor ON are failure, and disconnection.
Judging condition The feed-back signal is 24V level while exciting command is not output.
Symptom Travel 2 speed is not obtainable or is keeping 1 speed.
Control in the
Normal control
event of failure
Returned in
The feed-back signal is grounding level while exciting command is not output.
normal condition
Screen No. 3 F-3 1/2-TRAVEL
Service diagnosis
Screen No.
checking screen
Screen No.
1 -Travel 1, 2speed solenoid valve When F033 is cancelled and other error occurs by exchanging the
2 -Wiring between travel 1, 2speed When F033 is displayed after the connector is exchanged with other
Table 46-43
Error code G032
Trouble Mechatro controller direct input speed sensor is overrun.
Judging
Engine rpm input is 3000rpm or more. (Only trouble history)
condition
Symptom Operate without problem.
Control in the
Engine speed slows down to 0 rpm.
46
event of failure
Returned in
normal condition
Service Screen No. 2 G-3 MEAS 1 (for mechatro controller)

1 -Engine speed sensor Measure the resistance between terminals of speed sensor.
SE-13 Normal value: 1.6 to 2.0 kilo-ohms
2 -Wiring between engine Check wiring for possible failure according to the wiring checking
speed sensor and controller procedure and repair it if necessary.
CN-136F Especially check wiring for false disconnection and noise included.
CN-106F
(Controller is broken by only applying power to grounding of signal.)
46-31
Table 46-44
Error code G033
Trouble Mechatro controller direct input speed sensor, Disconnection
Judging
Voltage of alternator is 12V or more, and speed sensor indicates excess low engine rpm.
condition
Symptom Operate without problem.
Control in the
Normal control
event of failure
Returned in
normal condition
Service Screen No. 2 G-3 MEAS 1 (for mechatro controller)

1 -Engine speed sensor Measure the resistance between terminals of speed sensor.
SE-13 Normal value: 1.6 to 2.0 kilo-ohms
2 -Wiring between engine Check wiring for possible failure according to the wiring checking
speed sensor and controller procedure and repair it if necessary.
CN-136F
CN-106F
(Controller is broken by only applying power to grounding of signal.)
Table 46-45
Error code H013
Trouble Accel potentiometer is disconnected.
Judging
The input voltage from accel potentiometer is 0.1V or less.
condition
Symptom LOW idling is fixed.
Control in the
LOW idling is fixed.
event of failure
Returned in
normal condition
Service Screen No. 2 H-1 ACCEL VOLT.

1 -Accel potentiometer Measure the resistance between terminals of speed sensor. 1.6 to 2.4
SE-16 kilo-ohms
Turn the potentiometer and measure resistance between signal and GND.
2 -Wiring between accel Check wiring for possible failure according to the wiring checking
potentiometer and controller procedure and repair it if necessary.
CN-402F
CN-102F
46-32
Table 46-46
Error code H014
Trouble Accel potentiometer's power source is shortcut.
Judging
The input voltage from accel potentiometer is 4.7V or more.
condition
Symptom LOW idling is fixed.
Control in the
LOW idling is fixed.
event of failure
Returned in
normal condition
Service Screen No. 2 H-1 ACCEL VOLT.

1 -Accel potentiometer Measure the resistance between terminals of accel potentiometer.
SE-16 1.6 to 2.4 kilo-ohms
Turn the potentiometer and measure resistance between signal and GND.
2 -Wiring between accel Check wiring for possible failure according to the wiring checking
potentiometer and controller procedure and repair it if necessary.
CN-402F
CN-102F
Table 46-47
Error code H081
Trouble Grounding of coolant temperature sensor is short-circuited.
Judging
The input voltage from coolant temperature sensor is 0.1V or less.
condition
Symptom The water temperature is fixed to 20 degrees C.
Control in the
Normal control
46
event of failure
Returned in
normal condition
Service Screen No. 2 G-5 The lower side of water temperature meter on gauge cluster is fixed.
1 -Coolant temperature sensor Measure the resistance between terminals.
SE-14 20 degrees C 10 ohms to 878 ohms
2 -Wiring between coolant Check wiring for possible failure according to the wiring checking
temperature procedure and repair it if necessary.
sensor and controller
F-4
CN-104
46-33
Table 46-48
Error code H091
Trouble Fuel sensor grounding is short-circuited.
Judging
The input voltage from fuel sensor is 0.1V or less.
condition
Symptom Warning for low fuel level is indicated.
Control in the
Fuel level becomes 0%.
event of failure
Returned in
normal condition
Service Screen No. 10 H-9 FUEL LEVEL

1 - Fuel sensor potentiometer Move fuel sensor and measure the resistance between terminals of fuel
SE-15 sensor.
EMPTY 95 ohms to FULL 5 ohms
2 -Wiring between fuel Check wiring for possible failure according to the wiring checking
sensor and controller procedure and repair it if necessary.
CN-152F
CN-104F
Table 46-49
Error code H093
Trouble Fuel sensor's wiring is disconnection.
Judging
The input voltage from fuel sensor is 4.7V or more.
condition
Symptom Warning for low fuel level is indicated.
Control in the
Fuel level becomes 0%.
event of failure
Returned in
normal condition
Service Screen No. 10 H-9 FUEL LEVEL

1 - Fuel sensor potentiometer Move fuel sensor and measure the resistance between terminals of fuel
SE-15 sensor.
EMPTY 95 ohms to FULL 5 ohms
2 -Wiring between fuel Check wiring for possible failure according to the wiring checking
sensor and controller procedure and repair it if necessary.
CN-152F
CN-104F
46-34
Table 46-50
Error code I313
Trouble Reception of cluster communication is abnormal. (Time-out error)
Judging
Reception from gauge cluster can not receive correctly.
condition
Symptom Switch operation of gauge cluster can not be done.
Control in the
Keep the condition after immediately key-on is operated.
event of failure
Returned in
normal condition
Service Screen No.

1 -Wiring between gauge cluster Check wiring for possible failure according to the wiring checking
and controller procedure and repair it if necessary.
CN-600F
CN-101F
46
46-35
Table 46-51
Error code K014
Trouble Battery relay contact welded
Judging The power 24V is continuously supplied to controller for 40 seconds or more while the key
condition switch ON signal turned OFF
Symptom The power on the battery relay secondary side does not turn OFF even if the key switch is
turned OFF.
Control in the
Normal control with key switch OFF
event of failure
Returned in Turn key switch ON.
normal condition Or when the power supply 24V to mechatro controller is stopped
Service Screen No. 4 K-1 AIS RELAY 2

diagnosis Screen No. 4 K-3 KEY SWITCH OFF
1 -Battery relay Turn key switch off and disconnect the connector (CN-256F) on the
R-1 battery relay coil. If 24V power lives on battery relay secondary side,
CN-256F check on battery relay for failure and replace it if failed.
2 -Auto idle stop relay 2 Turn off the key switch, and remove the connector (CN-256F) on the
R-24 battery relay coil side. If power of battery relay on secondary side falls,
-Alternator relay remove either auto idling stop relay 2 or alternator relay.
R-28 The failure may be occurred in case where the power falls after the
relay was removed, and therefore check on the relay unit and replace it
with new one if failed.
3 -Wiring between auto idle stop When K014 is left displayed with the relay removed
relay/alternator relay and Check that no power 24V is produced on relay (-) line according to the
controller wiring checking procedure and replace it if necessary.
CN-109F, CN2-1 When no failure found after checking on wiring and K014 is left displayed
-Fuse & relay box Replace fuse/relay box.
E-1
46-36
46
46-37
46-38
46
46-39
46-40
46
46-41
46-42
［47. TROUBLESHOOTING (BY TROUBLE)］
47. TROUBLESHOOTING
(BY TROUBLE)
TABLE OF CONTENTS
47.1 HYDRAULIC SYSTEM …………………………………………………………………………………………47-3

47.2 ELECTRIC SYSTEMS …………………………………………………………………………………………47-25
47.2.1 WIRING CHECKING PROCEDURE ……………………………………………………………………47-25
47.2.2 TROUBLE……………………………………………………………………………………………………47-28
47.3 ENGINE RELATED TROUBLESHOOTING …………………………………………………………………47-31
47
47-1

S5LF4712E01
First Edition June, 2010 SK80CS-2 : LF06-04501~
(NA)
SK70SR-2 : YT06-18001~
(NA)
October, 2010 SK70SR-2 : YT06-18444~

(AUS)
47-2
47.1 HYDRAULIC SYSTEM
Preface:
The troubleshooting for the failures shown below is explained here.
Identify the failure and trouble and carry forward the troubleshooting in order of the failure item number.
(1) All controls do not function/slow

(2) Engine down/stalled
(3) Move at lever neutral position
(4) Poor fine operability
(5) When auto deceleration function is ON and lever is in neutral, engine rpm dose not decrease.
When the lever is operated, engine rpm dose not increase.
(6) Slow boom up, insufficient power
(7) Slow boom down, insufficient power for lifting up body
(8) Slow arm in, insufficient power
(9) Slow arm out, insufficient power
(10) Slow bucket digging, insufficient power
(11) Slow bucket dumping, insufficient power
(12) Slow dozer up, insufficient power
(13) Slow dozer down, insufficient power for lifting up body
(14) Swing operation not functioned/slow
(15) Noise during swing operation
(16) Swing on a slope drifts when control lever is in neutral position
(17) Swing drifts when swing operation is stopped
(18) Slow travel speed/weak
(19) Travel deviation
(20) Travel 1st/2nd speed not changed
(21) Travel parking on a slope is not held
(22) Travel does not run straightly when both crawlers and attachment operated simultaneously.
(23) Slow breaker (crusher) operation, weak power
(24) Selector valve malfunction: not switched to breaker circuit
(25) Selector valve malfunction: not switched to nibbler (crusher) circuit
(26) Boom right swing is slow.
(27) Boom left swing is slow.
47
47-3
(1) All controls do not function/slow

No. Sections Contents/normal value Corrective action, others
1 Safety lever lock Check that the Measure both terminals of Check solenoid unit for
switching solenoid is solenoid connector. 24V by pushing possible failure.
switched correctly the lever down, 0V by pushing it Check harness for
up possible failure.
2 Solenoid valve for Measure About 0MPa by pushing the lever Replace solenoid valve
safety lock lever pressure of up, and 3MPa or more by push it
solenoid A1 port down.
3 Pilot line filter Disassemble and Check filter for clogging Clean filter
check it visually
4 Pilot gear pump Measure pilot Check that it is 3MPa or more in Check gear pump and the
primary pressure high idling relief valve for possible
at gear pump failure
5 Multi control valve Change position Since all are blocked due to poor
(in case that switching performance, check that
travel is operable) the lever select pattern is set to
the proper position.
6 Negative control Measure negative Check that negative control Check flow control valve
pressure control pressure pressure decreases in boom up full
at Pn port of lever, high idling compared with
control valve lever neutral.
7 Flow control valve Visual check When removing, free from Spring is free from
abnormal resistance against breakage.
sliding. Free from abnormal
damage on outside of valve.
8 Main relief pressure Check set -See Service Diagnosis Data List Measure the relief
pressure Operation No.3 Boom up full lever pressure actually
& relief
Check that pump pressure is Replace
26MPa or more in boom up full
lever, high idling and H mode
operation.
9 Pump regulator Visual check When removing, free from Replace
abnormal resistance against sliding.
Free from abnormal damage on
outside of regulator.
Spring free from breakage and
damage.
10 Pump Visual check When removing, inside parts Replace
(cylinder block, piston, valve plate,
shaft, etc.) are free from abnormal
resistance against sliding and
abnormal damage.
47-4
(2) Engine down/stalled

Spring free from breakage.
2 Pump Visual check When removing, inner parts Replace
abnormal damage.
(3) Move at lever neutral position

1 Remote control Measure the Check that targeted pilot pressure Check remote control
pressure targeted remote is 0MPa. valve
control pressure
directly
2 Remote control Check targeted Check that spool is free from Replace
valve remote control abnormal damage and Spring is
valve free from breakage.
3 Main spool Check targeted Check that spool is free from Replace
spool visually abnormal damage and Spring is
free from breakage.
4 Over load relief Check targeted Free from dust entered in port Replace
valve spool visually relief valve. Seat is free from
abnormality
5 Lock valve poppet Check targeted Seat is free from abnormality Replace
(in case of boom poppet visually
and arm)
6 Lock valve selector Exchange lock Check that the trouble is reversed Replace
(in case of boom valve selector of
and arm) boom/arm and
boom/arm
7 Holding valve spool Check that Free from abnormal resistance Replace
for boom smooth sliding of against sliding. Do not pull spool out of
(* In case that spool in sleeve sleeve forcibly. 47
this machine
equips the boom
H/V)
8 Holding valve Check targeted Filter free from abnormal Replace
relief valve for spool visually contamination
boom
(* In case that
this machine
equips the boom
H/V)
9 Cylinder Check targeted Make sure of no problem of seals Replace cylinder or seals
cylinder visually by disassembling and investigation
47-5
(4) Poor fine operability

1 Main spool Check targeted Free from abnormal damage and Replace
spool visually spring breakage
2 Slow return check Visual check Check that slow return valve
valve of pilot line installed on pilot line is free from
(Boom down) dust entered.
(5) When auto deceleration function is ON and lever is in neutral, engine rpm dose not
decrease. When the lever is operated, engine rpm dose not increase.
1 Pilot pressure Carry out Service At full lever position : Replace the targeted
sensor Diagnosis to ATT and Swing operations are to pilot pressure sensor
check the targeted be 3.0 MPa, and other operations
pilot secondary are to be 2.1 MPa or more.
pressure.
47-6
(6) Slow boom up, insufficient power

1 Boom up pressure Carry out service -See Service Diagnosis Data List Check and replace
sensor diagnosis Operation No.3 boom up full lever pressure sensor
and relief Check remote control
valve
2 Pilot proportional Measure directly Check that pressure is 3.0MPa or Check remote control
secondary pressure remote control more in boom up full lever and valve
pressure of high idling operation When equipped with
boom up (b5 port) multi control valve, check
it while changing lever
pattern
4 Lock valve poppet Visual check Free from abnormal resistance Replace
<Trouble> against sliding. (Check on the casing for
Pump pressure is Free from abnormal damage on damage)
high. outside of valve
5 Holding valve for Visual check Free from abnormal resistance Replace
boom (poppet) against sliding. (Check on the casing for
(* In case that Free from abnormal damage on damage)
this machine outside of valve
equips the boom
H/V)
<Trouble>
Pump pressure is
high.
6 Boom spool Visual check Free from abnormal resistance Replace
<Trouble> against sliding. (Check on the casing for
Pump pressure is Spring is free from breakage. damage)
high.
7 Check boom Visual check Free from abnormal resistance Replace spool assembly
spool for against sliding. (Check on the casing for
recirculation Spring is free from breakage. damage)
<Trouble>
Pump pressure is
low.
8 Main relief valve Check set Operation : Boom up full lever Replace 47
<Trouble> pressure from Pd1 and relief 26MPa or more
Relief pressure is port on pump
low.
9 Over load relief Visual check Pressure is 26MPa or more in When only relief
valve (Head side) boom up full lever and high idling. pressure of boom up is
<Trouble> Free from dust entered in over low, replace valve
Relief pressure is load relief valve. Seat is free from
low. abnormality
10 Pressure Visual check Free from abnormal resistance Replace
compensation valve against sliding. (Check on the casing for
for boom Free from abnormal damage on damage)
outside of valve
47-7
(7) Slow boom down/insufficient power for lifting up body

1 Boom down Carry out service -See Service Diagnosis Data List Check and replace
pressure sensor diagnosis Operation No.5 boom down full pressure sensor
lever and relief Check remote control
valve
2 Pilot proportional Measure remote Check that pressure is 3.0MPa or Check remote control
secondary pressure control pressure more in boom down full lever and valve
of boom down high idling operation When equipped with
directly (a5 port) multi control valve, check
pattern.
3 Remote control valve Check targeted Check that spool is free from Replace
remote control abnormal damage and Spring is
4 Lock valve poppet Visual check When removing, free from Replace
<Trouble> abnormal resistance against sliding. (Check on the casing for
Boom down is low. Free from abnormal damage on damage)
outside of valve
5 Holding valve Visual check When removing, free from Replace
(poppet) abnormal resistance against sliding. (Check on the casing for
(* In case that Free from abnormal damage on damage)
this machine outside of valve
equips the boom

H/V)
<Trouble>
Boom down is
slow.
6 Boom spool Visual check When removing, free from Replace
Boom down is slow. Free from abnormal damage on damage)
outside of valve
Spring is free from breakage.
7 Check boom spool Visual check Free from abnormal resistance Replace
for recirculation against sliding. (Check on the casing for
<Trouble> Spring is free from breakage. damage)
Machine can not
be lifted by
supporting with
boom.
8 Main relief valve Measure pump Operation : Boom up full lever Replace
<Trouble> pressure from Pd1 and relief 26MPa or more
Relief pressure is port on pump
low.
9 Over load relief Visual check Free from dust entered in port Replace
valve relief valve.
<Trouble> Seat is free from abnormality
Machine can not
be lifted by
supporting with
boom.
47-8

10 Pressure Visual check Free from abnormal resistance
compensation valve against sliding. and Spring is free
for boom from breakage.
(8) Slow arm in, insufficient power

1 Arm in pressure Carry out service -See Service Diagnosis Data List Check and replace
sensor diagnosis Operation No.6 arm in full lever pressure sensor
valve
secondary pressure pilot proportional more in arm in full lever and high valve
secondary idling operation When equipped with
pressure of arm multi control valve, check
in (b7 port) it while changing lever
pattern
4 Main relief valve Check set Operation : Boom up full lever Replace
<Trouble> pressure of and relief 26MPa
Relief pressure is pump from Pd1
low. port
5 Over load relief Visual check Pressure is 26MPa or more in When only relief
valve (Head side) arm in and relief. pressure of arm in is
Pump pressure is load relief valve.
low. Seat is free from abnormality
6 Arm spool Visual check When removing, free from Replace
high. outside of spool.
7 Check arm spool Visual check Free from abnormal resistance Replace
for recirculation against sliding. (Check on the casing for
<Trouble>
Arm in is slow.
Spring is free from breakage. damage)
47
8 Check lock valve Visual check Free from abnormal resistance Replace
poppet against sliding. (Check on the casing for
<Trouble> Free from abnormal damage on damage)
Pump pressure is outside of poppet.
high.
9 Arm pressure Visual check Free from abnormal resistance Replace
47-9
(9) Slow independent arm out (in the air)

1 Arm out pressure Carry out service -See Service Diagnosis Data List Check and replace
sensor diagnosis Operation No.8 arm out full lever pressure sensor
valve
2 Remote control Measure directly Check that pressure is 3.0MPa or Check remote control
valve remote control more in arm out full lever and high valve
pressure of arm idling operation When equipped with
out (a7 port) multi control valve, check
pattern
<Trouble> pressure of and relief 26MPa or more
low. port
5 Over load relief Visual check (Rod Pressure is 26MPa or more in When only relief
valve side) arm out and relief. pressure of arm out is
Pump pressure is load relief valve. Seat is free from
low. abnormality
6 Arm spool Visual check When removing, free from Replace
high. outside of spool
7 Check arm spool Visual check Free from abnormal resistance Replace
for recirculation against sliding.
<Trouble> Spring is free from breakage.
Pump pressure is
low.
8 Check lock valve Visual check Free from abnormal resistance Replace
poppet against sliding. (Check on the casing for
Pump pressure is outside of poppet
high.
9 Arm pressure Visual check Free from abnormal resistance Replace
47-10
(10) Bucket digging is slow

1 Bucket digging Carry out service -See Service Diagnosis Data List Check and replace
pressure sensor diagnosis Operation No.12 bucket digging pressure sensor
full lever and relief Check remote control
valve
secondary pressure remote control more in bucket digging full lever valve
pressure of bucket and high idling operation When equipped with
digging (b port) multi control valve, check
pattern
low. port
5 Bucket spool Visual check When removing, free from Replace
6 Over load relief Check targeted Free from dust entered in over Replace
valve spool visually load relief valve.
Seat is free from abnormality.
7 Check valve for Visual check Free from abnormal resistance Replace
bucket recirculation against sliding.
for bucket Spring is free from breakage. damage)
47
47-11
(11) Bucket dump is slow

1 Bucket dump Carry out service -See Service Diagnosis Data List Check and replace
pressure sensor diagnosis Operation No.14 bucket dump full pressure sensor
valve
2 Pilot proportional Measure directly Check that pressure is 3.0 MPa Check remote control
secondary pressure remote control or more in bucket dump full lever valve
pressure of bucket and high idling operation When equipped with
dump multi control valve, check
pattern
low. port
5 Bucket spool Visual check When removing, free from Replace
Both P1, P2 Free from abnormal damage on damage)
pressures are high. outside of spool
7 Check valve for Visual check Free from abnormal resistance Replace
bucket recirculation against sliding.
for bucket Spring is free from breakage. damage)
47-12
(12) Slow dozer up, insufficient power

1 Dozer up pressure Carry out service -See Service Diagnosis Data List Check and replace
sensor diagnosis Operation No.11 Dozer up full lever pressure sensor
valve
secondary pressure remote control more in dozer up full lever and valve
pressure of high idling operation
dozer up (b4 port)
<Trouble> pressure of and relief 26MPa
low. port
5 Dozer spool Visual check When removing, free from Replace
for dozer Spring is free from breakage. damage)
47
47-13
(13) Slow dozer down, insufficient power for lifting up body

1 Dozer down Carry out service -See Service Diagnosis Data List Check and replace
pressure sensor diagnosis Operation No.12 Dozer down full pressure sensor
valve
secondary pressure remote control more in dozer down full lever and valve
pressure of high idling operation
dozer down (a4
port)
4 Dozer spool Visual check When removing, free from Replace
Both P1, P2 Free from abnormal damage on damage)
pressures are high. outside of spool
low. port
for dozer Spring is free from breakage. damage)
47-14
(14) Swing does not move/slow

1 Swing pressure Carry out service -See Service Diagnosis Data List Check and replace
sensor diagnosis Operation No.6 Swing full lever and pressure sensor
in operation Check remote control
valve
secondary pressure remote control more in boom up full lever and valve
pressure of swing high idling operation When equipped with
multi control valve, check
pattern
3 Swing parking Carry out service No.3 F-2 SWING-BRAKE Check swing pressure
brake solenoid diagnosis Lever neutral: COMP ON, MEAS sensor
ON Check harness
Swing: COMP OFF, MEAS OFF
Measurement of Lever neutral: 0MPa Replace solenoid valve
solenoid valve A2 In operation: 3MPa or more
port
5 Swing spool Visual check When removing, free from Replace
compensation valve against sliding. (Check on the casing side
for swing Spring is free from breakage for damage)
7 Swing relief valve Check set Operation : Swing full lever and Reset or replace
<Trouble> pressure relief 26MPa or more
Relief pressure is
low.
8 Swing motor Visual check Inner parts (cylinder block, piston, Replace
valve brake etc) are to be Free
from abnormal resistance against
sliding.
Free from abnormal damage on 47
outside of brake plate etc.
9 Swing reduction Take sample oil Sampling oil does not include a Disassemble and inspect
gear oil from swing lot of metal powder. reduction gear
reduction gear
drain
10 Swing reduction Visual check Tooth surface is not worn Replace
abnormally and is not chipped.
47-15
(15) Noise occurred at swing operation

ON Check harness
Swing: COMP OFF, MEAS OFF
port
2 Boost check valve Visual check When removing, free from Replace
(Sound of abnormal resistance against sliding.
cavitation at Spring is free from breakage.
stopping)
3 By-pass check Visual check When removing, free from Replace
valve abnormal resistance against sliding.
(Sound of Spring is free from breakage.
cavitation at
stopping)
4 Swing motor Visual check Disassemble and inspect abnormal Replace
Brake valve/friction wear and scuffing
plate)
5 Swing motor piston Visual check When removing, free from Replace
6 Swing reduction Take sample oil Sampling oil does not include a Disassemble and inspect
gear oil from swing lot of metal powder. reduction gear
reduction gear
drain.
7 Swing reduction Visual check Tooth surface has no abnormally Replace
worn and chipped.
47-16
(16) Swing drifts on a slope while swing control lever is in neutral position
1 Swing pressure Carry out service -Engine stop & starter key ON Check and replace
sensor diagnosis All pilot low pressure sensors are pressure sensor
within range of 0 to 0.1MPa.
ON Check harness
Swing: COMP OFF, MEAS OFF Check parking brake
release switch
port
4 Swing motor Visual check Disassemble and inspect abnormal Replace
(Brake valve/friction wear and scuffing
plate)
5 Parking brake Visual check Piston and friction plate do not Replace
have abnormal resistance against
sliding
Free from spring damage
(17) Swing drifts at stopping

1 Swing pressure Carry out service -Engine stop & starter key ON Replace pressure sensor
sensor diagnosis All pilot low pressure sensors are
within range of 0 to 0.1MPa.
2 Swing relief valve Check set Operation : Swing full lever and Reset or replace
<Trouble> pressure relief 26MPa or more
Relief pressure is
low.
3 Anti-reaction valve Visual check Free from dirt entering Clean or replace
Sliding part should be free from
foreign matter entering, abnormal
damage and wear.
47
5 Swing motor Visual check Inner parts (cylinder block, piston, Replace
valve brake etc) are to be Free
from abnormal resistance against
sliding.
47-17
(18) Travel speed is slow/poor

1 Travel right and left Carry out service No.6 B-9, B-10 Check and replace
pressure sensor diagnosis Operation : Travel right full lever pressure sensor
and idling Check remote control
Operation : Travel left full lever valve
and idling
2 Secondary pressure Measure the pilot Check that the secondary Check remote control
of pilot proportional proportional valve pressures of travel right (left), valve
valve secondary forward (reverse) full lever and high
pressure directly idling operation
Pressure : 3.0MPa or more
Check sealing ability of shuttle
valve and entry of dust in orifice
4 Travel spool Visual check When removing, free from Replace
for travel Spring is free from breakage. damage)
6 Travel motor relief Check set Check pump pressure is 29MPa Lock travel motor and
valve pressure or more in right and left travel relieve oil, and identify
levers full lever (relief operation at which travel motor is
locked crawler belt) and high idling lower in relief pressure.
And lower pressure
motor is failed.
7 Travel motor Visual check Inner parts (piston, cylinder block, Replace
valve plate, brake valve spool) are
to be free from abnormal
resistance against sliding.
8 Parking brake in Visual check When removing, free from Replace
travel motor abnormal resistance against sliding.
No sticking on friction plate and
separator plate.
9 Travel reduction Take sample oil Sampling oil does not include a Disassemble and inspect
gear oil from travel lot of metal powder. reduction gear
reduction gear
drain
10 Travel reduction Visual check Tooth surface is not worn Replace
47-18
(19) Travel deviation

1 Travel right and left Carry out service No.6 B-9, B-10 Check and replace
pressure sensor diagnosis Operation : Travel right full lever pressure sensor
and idling Check remote control
Operation : Travel left full lever valve
and idling
2 Secondary pilot Measure directly Check that pressure is 2.1MPa or Check remote control
proportional valve remote control more in travel right (left), forward valve
pressure of travel (reverse) full lever and high idling
right and left operation
valve remote control abnormal damage and spring is
valve free from breakage. Check sealing
ability of shuttle valve and entry
of dust in orifice
4 Right and left Exchange right for Check the direction of deflection If the direction is
travel spool left travel spool changed, replace the
spool. If the direction is
not changed, inspect a
pressure compensation
valve for right/left travel
and travel unit.
5 Right / left travel Visual check When removing, free from Replace
pressure abnormal resistance against sliding. (Check on the casing for
compensation valve Free from abnormal damage on damage)
outside of valve.
6 Travel spool Visual check of When removing, free from Replace
<Trouble> targeted spool abnormal resistance against sliding. (Check on the casing for
7 Travel motor relief Check set Check pump pressure is 26MPa Lock travel motor and
valve pressure or more in right and left travel relieve oil, and identify
levers full lever (relief operation at which travel motor is
locked crawler belt) and high idling lower in relief pressure.
And lower pressure
motor is failed. 47
8 Travel motor Visual check Inner parts (piston, cylinder block, Replace
valve plate, brake valve spool) are
to be free from abnormal
resistance against sliding.
9 Travel reduction Take sample oil Sampling oil does not include a Disassemble and inspect
gear oil from travel lot of metal powder. reduction gear
reduction gear
drain
10 Travel reduction Visual check Tooth surface is not worn Replace
47-19

damage.
12 Pump Visual check When removing, inside parts Replace
abnormal damage.
(20) Travel 1, 2 speed cannot be switched

(In case of the traveling under heavy loading (for example traveling on a slope or traveling on a soft
ground), the speed may sometimes does not change from 1st to 2nd because this machine equips the
function of automatic speed change.)

1 Travel 1, 2 speed Carry out service Switch Travel 1, 2 speed to 2nd Check pressure sensor
switching solenoid diagnosis speed No.3 F-3 1/2-TRAVEL Check harness
Lever neutral COMP OFF, MEAS Check Travel 1, 2 speed
OFF switch on gauge cluster
Travel operation COMP ON, MEAS
ON
Measure A2 port Lever neutral: 0MPa Replace solenoid valve
pressure on In operation: 3MPa or more
solenoid valve
2 1, 2 speed Visual check Check that spool is free from Replace
switching spool in abnormal damage and Spring is (Check on the casing for
travel motor free from breakage. damage)
3 1, 2 speed Visual check Free from entry of dust Remove dust or replace
switching orifice in
travel motor
4 Tilting piston in Visual check Free from abnormal wear on piston Replace
travel motor and seal (Check on the casing for
damage)
47-20
(21) Machine does not stay on a slope in traveling

1 Pilot pressure Carry out service -Engine stop & starter key switch Check pressure sensor
sensor diagnosis is ON and replace as necessary
Targeted pilot low pressure sensor Check remote control
is in range of 0 to 0.1MPa valve
3 Parking brake in Visual check When removing, free from Replace
travel motor abnormal resistance against sliding.
damage.
4 Orifice of passage Visual check Free from entry of dust Remove dust or replace
for parking brake
in travel motor
(22) Machine does not travel straight in simultaneous operation of traveling and attachment
1 Right / left travel Visual check When removing, free from Replace
pressure abnormal resistance against sliding. (Check on the casing side
compensation valve Free from abnormal damage on for damage)
outside of valve.
47
47-21
(23) Breaker works slowly and power is poor

1 Breaker pressure Carry out service -See Service Diagnosis Data List Check and replace
sensor diagnosis Operation No.13, No.14 in full lever pressure sensor
valve
2 Secondary pressure Measure directly Check pressure is 2.1MPa or Check the ermote control
of proportional valve the proportional more in breaker attachment full valve
valve secondary lever and high idling operation
pressure of N&B
3 Remote control Check targeted Check sealing ability of shuttle Replace
valve remote control valve and entry of dust in orifice.
valve
4 Relief pressure Check set Operation of breaker full lever and Reset or replace
pressure relief
(Set value of factory shipment is
26MPa.)
5 Spool for optional Visual check When removing, free from Replace
attachment abnormal resistance against sliding. (Check on the casing for
Pump pressure is outside of spool.
high. Spring is free from breakage.
valve spool visually load relief valve
7 Pressure Visual check When removing, free from Replace
compensation valve abnormal resistance against sliding. (Check on the casing for
for N&B Free from abnormal damage on damage)
outside of valve.
(24) Selector valve malfunctions: Breaker circuit is not obtained.

1 N&B selector spool Check the Does the lever switched correctly Replace
switching (Check on the casing for
damage)
2 N&B selector spool Visual check When removing, free from Replace
abnormal resistance against sliding. (Check on the casing for
Free from abnormal damage on damage)
outside of spool.
compensation valve abnormal resistance against sliding. (Check on the casing for
for N&B Free from abnormal damage on damage)
outside of valve.
47-22
(25) Selector valve malfunctions: Nibbler circuit is not obtained.

1 N&B selector spool Check the Does the lever switched correctly. Replace
switching (Check on the casing side
for damage)
2 N&B selector Visual check When removing, free from Replace
solenoid abnormal resistance against sliding. (Check on the casing side
Free from abnormal damage on for damage)
outside of valve.
compensation valve abnormal resistance against sliding. (Check on the casing side
for N&B Free from abnormal damage on for damage)
outside of valve.
(26) Slow boom swing right

1 Boom swing right Carry out service See Service Diagnosis Data List Check and replace
pressure sensor diagnosis Operation No.15 boom swing right pressure sensor
valve
secondary pressure pilot proportional or more in boom swing right full valve.
secondary lever and high idling operation.
pressure of
boom swing right
(b9 port)
3 Remote control Check targettd Check that spool is free from Replace
<Trouble> abnormal resistance against (Check on the casing for
Pump pressure is sliding. Free from abnormal damage)
high damage on outside of poppet.
5 Relief pressure Check set Operation : Relief pressure is 26.0 Reset or replace
pressure MPa or more at boom swing right
full lever 47
6 Boom swing spool Visual check When removing, free from Replace
high damage on outside of spool. Spring
is free from breakage.
abnormality
compensation valve abnormal resistance against (Check on the casing for
for boom swing sliding. Free from abnormal damage)
damage on outside of spool. Spring
47-23
(27) Slow boom swing left

1 Boom swing left Carry out service See Service Diagnosis Data List Check and replace
pressure sensor diagnosis Operation No.16 boom swing left pressure sensor
valve
secondary pressure pilot proportional or more in boom swing left full valve.
secondary lever and high idling operation.
pressure of
boom swing left
(a9 port)
3 Remote control Check targettd Check that spool is free from Replace
high damage on outside of poppet.
5 Relief pressure Check set Operation : Relief pressure is 26.0 Reset or replace
pressure MPa or more at boom swing left
full lever
6 Boom swing spool Visual check When removing, free from Replace
high damage on outside of spool. Spring
(ROD side) abnormality
compensation valve abnormal resistance against (Check on the casing for
for boom swing sliding. Free from abnormal damage)
damage on outside of spool. Spring
47-24
47.2 ELECTRIC SYSTEMS
47.2.1 WIRING CHECKING PROCEDURE

Check for continuity between connector terminals, presence or absences of short-circuit with other
wires, and presence or absences of short-circuit with machine body grounding.
(1)
Checking for disconnection between connectors.
(When both ends measurement is easy because
of short distance between connectors,)
Measure the resistance using tester.
Pull out opposite connector first.
When the resistance is zero (0), it is in normal
condition.
(When both ends measurement is difficult

because of long distance between connectors,)
Where the resistance is zero (0), if the
terminal on one side is connected to frame
body grounding with jumper wire, it is in normal
condition.
The resistance is 1M-ohm or more when the
terminal on one side is not connected to frame
body grounding with jumper wire, it is in normal
condition.
(2)
Checking for presence or absence of
short-circuit with machine body
When the resistance is 1M-ohm or more, it is
in normal condition.
47
(3)
Checking for presence or absence of
short-circuit between wirings.
When the resistance is 1M-ohm or more, it is
in normal condition.
47-25
(4)
Checking connector terminal for contact
Insert male terminal into female terminal unit,
and then check that the inserting force is
equivalent to other female terminals.
If looseness is there, replace the female
terminal with new one.
Clean the dirt terminal.
Do not insert the male terminal the thickness differs. It may cause loose connection.
(5)
Caution which should be paid in measuring voltage
When measuring the power supply to electric equipment at connector position with the grounding
terminal contained inside of connector, measure the voltage between grounding inside of connector and
power terminal.
When measuring the voltage between frame body grounding and power source, the disconnection of
wiring to grounding inside of connector cannot be identified.
Since the voltage may vary between with connector connected and with connector not connected.
Measure the voltage with each connector connected whenever possible.
(6)
Checking the general view of connector
a. Check the terminal crimped condition.

Pull one electric cable with the about 3kg
force, and make sure that the cable does
not come out of the terminal.
When came out, replace the terminal and
crimp it again.
b. Check connector for imperfect insertion
Check that all top ends form a line on the
same position as seen from the connector
engaged side.
When moved along, push it in further
through wire inserting hole.
c. Check connector for intruding of water.
Pull out the connector and check that the
inside is free from intruding of water.
When water intruding is found, check
rubber plug for damage and also that the
sealing is fitted properly.
47-26
(7)
When abnormality occurs at intervals
When the abnormality situation can not be reoccurred during checking operation, try the following
operations.
a. Check that variable of display exists or not on the service diagnosis screen while shaking the
harness or giving shock by operating the machine.
b. Check that variables of resistance and voltage exist or not using tester while shaking the harness.
c. Turn starter switch on and apply electricity continuously, and check it again after the temperature
of wiring and equipment was raised.
(8)
Checking on body grounding
Check attaching bolts of grounding terminal for
loosening.
And also check that there is no loose
connection due to corrosion.
There are multiple groundings like centralized

grounding box shown in the figure and battery
grounding, engine grounding, horn grounding
fixed together with horn, body grounding
placed on attaching section of boom working
light.
47
47-27
47.2.2 TROUBLE
(1) Engine does not stop.
(2) "CPU DATA COMMUNICATION ERROR" is displayed on multi display.
(3) Auto accel does not actuate. (The engine speed does not automatically slow down.)
(4) Auto accel does not actuate. (The engine speed does not automatically speed up.)
(5) Wiper does not function.
47-28
(1) Engine does not stop.

1 Starter key switch Check signal of No.4 K-3 Key switch Check continuity between
starter key switch OFF at starter key switch OFF terminals of starter switch
ON by carrying position using tester
out service ON at starter key switch ON
diagnosis. position
2 Engine forcible When ON is No.4 K-3 Key switch Check on engine forcible
stop relay displayed with OFF at starter key switch OFF stop relay
the starter switch position
OFF, then pull out ON at starter key switch ON
R-25 engine position
forcible stop
relay and carry
out the service
diagnosis.
3 Wiring Voltage between 0V when starter switch is OFF Check harness
line No.762 Check diode D-9
among starter between starter switch
switch, engine and auto idling stop relay
forcible stop relay, 1
mechatro
controller and the
body grounding
(2) "CPU DATA COMMUNICATION ERROR" is displayed on multi display.

1 Fuse No.1 fuse (5A) Not blown fuse Check harness
Replace fuse
2 Mechatro controller Accel control Engine speed varies according to Check mechatro
accel potentiometer operation. controller and replace as
(Use remote control because the necessary
auto accel function is working.)
3 Wiring Transmission See "WIRING CHECKING Repair wiring
circuit line PROCEDURE"
No.770 from
mechatro
controller to
gauge cluster
47
4 Gauge cluster Gauge cluster Replace gauge cluster
(3) Auto accel does not actuate. (The engine speed does not automatically slow down).
1 Gauge cluster Indication of auto Mark "Display/not display" for auto Replace gauge cluster
accel accel switches by auto accel switch
operation on gauge cluster.
2 Low pressure Service diagnosis Each control pressure of Check low pressure sensor
sensor No.2~No.16 is in the range of
0~0.1MPa at control lever neutral
position.
47-29
(4) Auto accel does not actuate. (The engine speed does not automatically speed up.)
1 Low pressure Service diagnosis Each control pressure of Check low pressure sensor
sensor No.2~No.16 is raised with control
lever operated.
(5) Wiper does not function
47-30
47.3 ENGINE RELATED TROUBLESHOOTING
47
47-31
47-32
47
47-33
47-34
［51. ENGINE］
51. ENGINE
PREFACE
51
This service manual explains the single engine. Note that this manual is edited without modification by
based on the service manual of ISUZU MOTORS, Ltd.
51-1
［51. ENGINE］

S5YT5112E01
First Edition July, 2009 SK70SR-2 : YT06-18001~
(SE Asia & Oceania)
August, 2009 SK80MSR-2 : LF06-04501~

(Oceania)
June, 2010 SK80CS-2 : LF06-04501~

(NA)
SK70SR-2 : YT06-18001~
(NA)
October, 2010 SK80MSR-2 : LF06-04547~

(AUS)
SK70SR-2 : YT06-18444~
(AUS)
51-2
INDUSTRIAL
DIESEL ENGINE
AU-4LE2X
MODEL
AU-4LE2X
ISUZU MOTORS LIMITED
07/12/05
IDE-2450
[S5YT0015E01] [0713CsCshWbYs]
General Information 0A-1
General Information
General Information
Table of Contents
General Information .............................................. 0A-2
Service Precautions ........................................... 0A-2
Reading the Model ............................................. 0A-7
General Information ........................................... 0A-8
Recommended Lubricant ................................. 0A-14
List of Trouble Symptom .................................. 0A-15
Repair Standard ............................................... 0A-24
0A-2 General Information
General Information
Service Precautions 5. Always use the correct specialized tool indicated in
the instructions. Using the incorrect tool may
In order to carry out work safely cause damage to the parts or injury to the person
1. Always use an engine stand when taking the using the tool.
engine down from the vehicle.
Do not place the engine directly onto the ground,
or place in a manner that interferes with the oil
pan.
2. If you are working together with others, always pay
attention to each other's safety.
3. If you are repairing any part of the electrical sys-
tem, always remove the minus side cable from the
battery terminal before starting work. If you are
removing the battery cover, always remove the
cover in a place that is away from sources of fire/
heat.
WSHK0190
6. All regular tools, gauges and special tools should

be regularly inspected, and prepared before start-
ing work. Do not use bent spanners, hammers with
damaged edges, chipped chisels, or any other
faulty or damaged tools.
4. Do not perform painting work or leave the engine

running for long periods of time in an enclosed or
badly ventilated indoor workshop.
7. Always pay close attention to safety and handling 9. Pay close attention to the risk of ignition if you are
requirements when using grinders, cranes, weld- handling parts that carry a high voltage.
ers, and other such equipment. Furthermore, any oil or grease spilt onto rubber
Moreover, always wear the correct protective gar- parts must be wiped off immediately, as it will
ments and use the necessary safety tools for the cause deterioration of the rubber.
job in hand.
WSHK0192
WSHK0191
8. Always check that there are no fuel leaks when Replacement parts and part numbers
performing maintenance work on the fuel system. 1. Always replace packing, oil seals, O-rings, caulk-
(It may cause a fire.) ing lock nuts, folding lock plates, split pins and
other such parts with brand new parts.
2. The parts numbers contained in this manual may
not represent the supply condition of the parts, and
the part numbers may be changed due to revi-
sions. Therefore, parts should always be checked
against a parts catalogue before use.
Liquid gasket 3. Please take care not to apply too much or too little
liquid gasket.
1. Each time you disassemble parts that use liquid
Also, you should always re-apply the liquid gasket
gasket, completely remove the old gasket residue
upon itself when you start and finish application.
from each of the parts and matching sections using
a scraper, then clean each of the parts to com- 4. Make sure that there are no gaps when reinstalling
pletely remove oil, water, and dirt etc. from the var- the liquid gasket parts to each other. If there are
ious surfaces by a cloth. Using the specified type gaps between the two parts, re-apply the liquid
of liquid gasket, apply new liquid gasket to each of gasket. Some parts, especially the oil pan, use the
the surfaces before reassembling the parts. same size studs as a guide to eliminate the need
for knock pin positioning etc.
2. In order to make it easier to clean liquid gasket sur-
faces, apply gasket remover liquid (Pando- 391D 5. Re-install these parts within 5 minutes of applying
made by ThreeBond Co., Ltd.) and leave the part the liquid gasket.
to stand for approximately 10 minutes, after which If more than 5 minutes passes, remove the previ-
the old liquid gasket residue will be easier to ous liquid gasket and re-apply it.
remove. 6. Please wait for at least 30 minutes since the last
However, this should not be used on resin compo- part is installed before starting the engine.
nents or painted components.
Liquid gasket
Applied area Use conditions

Liquid gasket
Parts Matching parts Seal object Application name
groove
Engine oil (10W
1 Rocker bracket Cylinder head Equipped TB 1207B
— 30)
2 Air inlet pipe Cylinder head cover Air Equipped TB 1207C
Engine oil (10W
3 Timing case Cylinder block Equipped TB 1207B
— 30)
Engine oil (10W
4 Housing cover; injection pump Cylinder block None TB 1207C
— 30)
Engine oil (10W
5 Solenoid; fuel cut Cylinder block Equipped TB 1207C
— 30)
Engine oil (10W
6 Retainer; oil seal Cylinder block Equipped TB 1207B
— 30)
7 Housing ASM; PCV Cylinder head cover Blow-by gas None TB 1207C
8 Indicator; air cleaner Air cleaner Air None (Seal tape)
• Always use the liquid gasket products listed above,

or a liquid gasket identical to the ones listed above.
• Use the correct quantity of liquid gasket. Always
follow the handling instructions for each product.
Application procedure Example: Procedure for measuring the clearance
1. Wipe the contact surfaces clean of all water, oil or between the connecting rod bearing and crank pin.
grease. The contact surfaces should be dry. • Clean the connecting rod and bearing, and install
2. Apply a regular bead width of liquid gasket to one the bearing to the rod.
of the contact surfaces. Make sure that the bead • Cut the plastigauge to the same width as the crank
does not break at this point. pin, and while avoiding the oil hole of the crank pin
lay the gauge parallel to the pin.
Note: • Line up the marks on the connecting rod and cap,
If there are special regulations concerning the applica- and install the crank pin. Apply molybdenum disul-
tion procedure in the repair document, please follow fide to the thread section and seating surface of
those regulations. the tightening bolt, and rotate both cap and bolt to
the correct torque.
Work procedure
1. Wipe the joint surfaces of the bolt, bolt hole, and Important:
threads clean of water, grease, and oil. The con- Do not move the connecting rod while using the
tact surfaces should be dry. plastigauge.
2. Apply Loctite to the top 1/3 of the screw.
• Gently remove the cap and connecting rod, and
3. Tighten the bolt to the specified torque. measure the crushed width of the plastigauge
(clearance between rod and pin) using the scale
printed on the bag.
Important:
After tightening the bolt, do not apply excessive
torque or try to rotate the bolt until at least one
hour has passed, and the Loctite has hardened.
Procedure for using the plastigauge
Type Measurable range mm {in}

PG-1 (Green) 0.025 — 0.076 {0.001 — 0.003}
PR-1 (Red) 0.051 — 0.152 {0.002 — 0.006}
PB-1 (Blue) 0.102 — 0.229 {0.004 — 0.009}
Example: Measuring the clearance between the crank
bearing and crank journal
• Clean the clamp face of the cylinder block and
crankcase bearing, and also the bearing, and
install the cylinder block to the crankcase.
• Gently rest the crankshaft on the cylinder block,
and rotate it approximately 30 degree to stabilize it.
• Cut the plastigauge to the same size as the journal
width, and while avoiding the oil hole of the journal
lay the gauge parallel to the journal.
• Gently rest the crankcase on the cylinder block,
apply molybdenum disulfide to the thread section
and seating surface of the tightening bolt, and
tighten in sequence to the correct torque.
Important:
Do not rotate the crankshaft while using the plasti-
gauge.
• Gently remove the crankcase, and measure the

crushed width of the plastigauge (clearance
between bearing and journal) using the scale
printed on the bag.
Reading the Model
Engine number stamping position
WSLE0352
General Information Description of abbreviations
Terminology, description of abbreviations
Abbrevia- Description
Terminology definitions tion
Maintenance standard AC Alternating Current
The generic name for reference values required for
ACC Accessory
maintenance, such as nominal dimension, assembly
specification, and limit. ACG Alternating Current Generator
Nominal dimension API American Petrol Institute
Shows the standard value at the point of manufacture ASM Assembly
that does not include the common difference. (Assy)
Assembly specification ATDC After Top Dead Center
Shows the standard value after assembling, repairing,
or adjusting. BAT, BATT Battery
BRG, Brg Bearing
Service limit
When this value (dimensions) is reached, it shows that BKT, BRKT Bracket
the part has reached its full limit and must be replaced
BTDC Before Top Dead Center
or repaired.
CO Carbon Oxide
Wear
Shows the difference between the dimension of non- CONN Connector
worn part (nominal dimension unless there is such part) CPU Central Processing Unit
and that of the most worn part (the dimension of worn
part). C/U Control Unit
DC Direct Current
Uneven wear
Shows the difference between the maximum and the DI Direct Injection
minimum wear amount. ECU Engine Control Unit/Electronic Control Unit
Front/Rear, Right/Left, Top/Bottom ECM Engine Control Module
These show each orientations of parts installed to the
vehicle when looking from the vehicle's forward direc- EGR Exhaust Gas Recirculation
tion. Exh, EXH Exhaust
Unit Ft, FRT Front
Units written to SI conventions (mainly torque, pres-
FWD Forward
sure, force)
[Example] Length: mm, Torque: N⋅m {kgf⋅m} F/C Fuel Cut
Warning GND Ground

Items that carry the warning mark pose a danger to life IC Integrated Circuit
or threat of serious injury if not strictly observed.
ID Plate Identification Plate
Caution
Items that carry the caution mark may cause injury or IN Intake, Inlet
lead to accidents if not strictly observed. ISO International Organization for Standardiza-
tion
Important
Items that carry the important mark may cause the I/PUMP Injection Pump
vehicle to break down, or may prevent the guaranteed JIS Japanese Industrial Standard
normal operation of the system or related parts if not
strictly observed. L/H, LH Left Hand
Note M/V Magnetic Valve

Items that should receive special mention within a work NOx Nitrogen Oxide
procedure.
N-TDC Number - Top Dead Center
OPT Option
P Pole(S)
PCV Pump Control Valve/Positive Crankcase
Ventilation
Abbrevia- Description SI (International System of Units)

tion With regards the conversion to SI (International
PM Particulate Matter System of Units)
PS Pre-Stroke The introduction of the SI systems aims to internation-
ally unify the metric system and the various units used
PTO Power Take Off by different countries (traditional weights and mea-
QOS Quick On System sures, the foot pound method etc.), and to curb the
confusion that occurs between the different units (con-
Rr, RR Rear
version calculations etc.).
R/H, RH Right Hand The new calculating method which adopted SI units
R/L Relay was completely adopted in Japan in 1992, and is stan-
dardized by JIS-Z-8203.
STD Standard All of the units in this manual are written in line
SW Switch with the International System of Units SI units, and
conventional units are written in { } brackets.
TICS Timing & Injection rate Control System
VGS Turbo Variable Geometry turbocharger System SI
Abbreviation of French word “Le Systeme International
W/L Warning Lamp
d’Unites”
Connection between main SI units and conventional units
SI Conventional unit Item, unit conversion

Length m m Same as the conventional unit
Weight (Mass) kg kg Same as the conventional unit
Force N * kg, kgf 1 kgf = 9.80665 N
Torque N⋅m * kg⋅m, kgf⋅m 1 kgf⋅m = 9.80665 N⋅m
Pressure Pa * kg/cm2, mmHg 1 kgf/cm2 = 9.80665 kPa, 1 mmHg = 133.3 Pa
Power output, W PS 1 PS = 0.74 kW
horsepower
Capacity, air vol- m3 Liter, L, cc 1 Liter = 1 dm3, 1 cc = 1 m Liter = 1 cm3
ume displacement
Fuel consumption g/(kW⋅h) g/(PS⋅h) 1 g/(PS⋅h) = 1.360 g/(kW⋅h)
*1 Published service data may conveniently use kg for force and mass (weight) instead of kgf.
*2 Some conversion results may be rounded off to 1 or 2 decimal places.
Converting expressions of quantity Conversion formula

When converting, prefixes such as k (kilo) or m (milli) Length
are used. • km × 0.6214 = mile
M Mega 106 1,000,000 • m × 3.281 = ft
• mm × 0.03937 = in
k Kilo 103 1,000
Pressure
h Hecto 102 100 • kPa × 0.0101972 = kg/cm2
d Deci 10-1 0.1 • kPa × 0.145038 = psi
c Centi 10-2 0.01 • MPa × 10.197162 = kg/cm2
m Milli 10-3 0.001 • MPa × 145.03774 = psi
Tightening torque
µ Micro 10-6 0.000001
• N⋅m × 0.101972 = kg⋅m
• 200 kgf/cm2 = 19,620 kPa = 19.6 MPa • N⋅m × 0.737562 = lb⋅ft
Speed
• 40 mmHg = 5,332 Pa = 5.3 kPa
• km/h × 0.6214 = MPH
Temperature
• °C × 1.8 + 32 = °F
Table of Isuzu standard tightening torque
The tightening torque values in the table below apply to all situations unless a special tightening torque is specified.
Isuzu standard bolts, nuts
N⋅m {kgf⋅m}
Strength classifica- 4.8
7T
tion 4T
Shape of bolt head Hexagon head bolt Flange bolt Hexagon head bolt Flange bolt
*M10 × 1.5 19.6 — 33.3 {2.0 — 3.4} 22.3 — 37.2 {2.3 — 3.8} 27.5 — 45.1 {2.8 — 4.6} 30.3 — 50.4 {3.1 — 5.1}
M12 × 1.25 49.0 — 73.5 {5.0 — 7.5} 54.9 — 82.3 {5.6 — 8.4} 60.8 — 91.2 {6.2 — 9.3} 68.1 — 102.1 {6.9 —
10.4}
*M12 × 1.75 45.1 — 68.6 {4.6 — 7.0} 51.0 — 76.5 {5.2 — 7.8} 56.9 — 84.3 {5.8 — 8.6} 62.7 — 94.0 {6.4 — 9.6}
M14 × 1.5 76.5 — 114.7 {7.8 — 83.0 — 124.5 {8.5 — 93.2 — 139.3 {9.5 — 100.8 — 151.1 {10.3 —
11.7} 12.7} 14.2} 15.4}
*M14 × 2 71.6 — 106.9 {7.3 — 77.2 — 115.8 {7.9 — 88.3 — 131.4 {9.0 — 94.9 — 142.3 {9.7 —
10.9} 11.8} 13.4} 14.5}
M16 × 1.5 104.0 — 157.0 {10.6 — 115.6 — 173.3 {11.8 — 135.3 — 204.0 {13.8 — 150.1 — 225.2 {15.3 —
16.0} 17.7} 20.8} 23.0}
*M16 × 2 100.0 — 149.1 {10.2 — 109.4 — 164.2 {11.2 — 129.4 — 194.2 {13.2 — 142.5 — 213.8 {14.5 —
15.2} 16.7} 19.8} 21.8}
M18 × 1.5 151.0 — 225.6 {15.4 — — 195.2 — 293.2 {19.9 — —
23.0} 29.9}
*M18 × 2.5 151.0 — 225.6 {15.4 — — 196.1 — 294.2 {20.0 — —
23.0} 30.0}
M20 × 1.5 206.0 — 310.0 {21.0 — — 269.7 — 405.0 {27.5 — —
31.6} 41.3}
*M20 × 2.5 190.2 — 286.4 {19.4 — — 249.1 — 374.6 {25.4 — —
29.2} 38.2}
M22 × 1.5 251.1 — 413.8 {25.6 — — 362.8 — 544.3 {37.0 — —
42.2} 55.5}
*M22 × 2.5 217.7 — 327.5 {22.2 — — 338.3 — 507.0 {34.5 — —
33.4} 51.7}
M24 × 2 358.9 — 539.4 {36.6 — — 430.5 — 711.0 {43.9 — —
55.0} 72.5}
*M24 × 3 338.3 — 507.0 {34.5 — — 406.0 — 608.0 {41.4 — —
51.7} 62.0}
The * mark indicates where soft materials have been used for internal thread sections, such as castings.
N⋅m {kgf⋅m}
Strength classifica- 9.8
8.8
tion 9T
Shape of bolt head Hexagon head bolt Flange bolt Hexagon head bolt Flange bolt
M6 × 1 5.6 — 11.2 {0.6 — 1.1} 6.6 — 12.2 {0.6 — 1.2} — —
M8 × 1.25 13.4 — 25.7 {1.4 — 2.6} 15.3 — 28.4 {1.6 — 2.9} 16.7 — 30.4 {1.7 — 3.1} 18.1 — 33.6 {1.9 — 3.4}
M10 × 1.25 31.3 — 52.5 {3.2 — 5.4} 35.4 — 58.9 {3.6 — 6.1} 37.3 — 62.8 {3.8 — 6.4} 42.3 — 70.5 {4.3 — 7.2}
*M10 × 1.5 31.3 — 51.4 {3.2 — 5.2} 34.5 — 57.5 {3.5 — 5.8} 36.3 — 59.8 {3.7 — 6.1} 40.1 — 66.9 {4.1 — 6.8}
M12 × 1.25 69.3 — 104.0 {7.1 — 77.7 — 116.5 {7.9 — 75.5 — 113.8 {7.7 — 85.0 — 127.5 {8.7 —
10.6} 11.9} 11.6} 13.0}
*M12 × 1.75 64.8 — 96.1 {6.6 — 9.8} 71.4 — 107.2 {7.3 — 71.6 — 106.9 {7.3 — 79.5 — 119.2 {8.1 —
10.9} 10.9} 12.2}
M14 × 1.5 106.2 — 158.8 {10.8 — 114.9 — 172.3 {11.7 — 113.8 — 170.6 {11.6 — 123.4 — 185.1 {12.6 —
16.2} 17.6} 17.4} 18.9}
*M14 × 2 100.6 — 149.8 {10.3 — 108.2 — 162.2 {11.1 — 106.9 — 160.0 {10.9 — 115.5 — 173.3 {11.8 —
15.3} 16.6} 16.3} 17.7}
M16 × 1.5 154.3 — 232.5 {15.7 — 171.1 — 256.7 {17.4 — 160.0 — 240.3 {16.3 — 176.9 — 265.3 {18.0 —
23.7} 26.2} 24.5} 27.1}
*M16 × 2 147.6 — 221.4 {15.0 — 162.5 — 243.8 {16.6 — 153.0 — 229.5 {15.6 — 168.5 — 252.7 {17.2 —
22.6} 24.9} 23.4} 25.8}
M18 × 1.5 222.5 — 334.3 {22.7 — — 229.5 — 345.2 {23.4 — —
34.1} 35.2}
*M18 × 2.5 223.6 — 335.4 {22.8 — — 230.5 — 346.2 {23.6 — —
34.2} 35.3}
M20 × 1.5 307.4 — 461.7 {31.4 — — 316.8 — 475.6 {32.3 — —
47.1} 48.5}
*M20 × 2.5 284.0 — 472.1 {29.0 — — 293.2 — 440.3 {29.2 — —
43.5} 44.9}
M22 × 1.5 413.6 — 620.5 {42.2 — — 424.6 — 636.5 {43.3 — —
63.3} 64.9}
*M22 × 2.5 385.7 — 578.0 {39.3 — — 394.2 — 592.3 {40.0 — —
58.9} 60.4}
M24 × 2 490.8 — 810.5 {50.0 — — 554.1 — 830.6 {56.5 — —
82.7} 84.7}
*M24 × 3 462.8 — 693.1 {47.2 — — 520.7 — 781.6 {53.1 — —
70.7} 79.7}
The * mark indicates where soft materials have been used for internal thread sections, such as castings.
Designations for Isuzu standard bolt heads
Name
1. Hexagon Head Bolt (4.8, 4T) 9. Hexagon Head Bolt (Nonthermal Refined 8.8)
2. Hexagon Head Bolt (4.8, 4T) 10. Hexagon Head Bolt (Nonthermal Refined 8.8)
3. Flange Bolt (4.8, 4T) 11. Flange Bolt (8.8)
4. Flange Bolt (4.8, 4T) 12. Flange Bolt (8.8)
5. Hexagon Head Bolt (7T) 13. Hexagon Head Bolt (9.8, 9T)
6. Flange Bolt (7T) 14. Hexagon Head Bolt (9.8, 9T)
7. Hexagon Head Bolt (Thermal Refined 8.8) 15. Flange Bolt (9.8, 9T)
8. Hexagon Head Bolt (Thermal Refined 8.8) 16. Flange Bolt (9.8, 9T)
Flare nut
Pipe diameter Tightening torque Width across flats of flare nut

(for medium and large size (mm)
vehicles)
Old New
Flare nut tightening torque φ 4.76 mm 12.8 — 18.6 {1.3 — 1.9} 14 14
(service standard value) N⋅m {kgf⋅m}
φ 6.35 mm 23.5 — 49 {2.4 — 5.0} 17 17
φ 8.0 mm 23.5 — 49 {2.4 — 5.0} 19 17
φ 10.0 mm 44.1 — 93.2 {4.5 — 9.5} 22 19
φ 12.0 mm 58.8 — 137.3 {6.0 — 14.0} 27 24
φ 15.0 mm 78.5 — 156.9 {8.0 — 16.0} 30 30
Taper screw from connectors (brass)
N⋅m {kgf⋅m}
Screw size PT (R) 1/8 PT (R) 1/4 PT (R) 3/8 PT (R) 1/12
— 2.0 — 14.7 4.9 — 15.7 9.8 — 16.7 9.8 — 17.7
{0.2 — 1.5} {0.5 — 1.6} {1.0 — 1.7} {1.0 — 1.8}
About angle method tightening

Though the general and current way to tighten bolts
and nuts is torque indication, using this way results in
large unevenness of shaft power to indicated torque.
Therefore, bolts may be damaged at upper limit when
you try to ensure minimal shaft power.
To ensure shaft power with small unevenness, it is nec- A
essary to tighten bolts measuring stretch amount of
C D
bolts, but this is actually impossible. So the angle
method focuses on screw pitch as equivalent to bolt
stretch, and controls using the screw rotation amount. B
E
The method can reduce the unevenness of shaft power
by tightening to plastic range.
F
How to tighten
1. Apply molybdenum disulfide or engine oil to the
threads and the seating surface of the bolt follow-
ing the instruction. WSLE0009
2. Tighten all bolts to the pre-indicated tightening

torque. Be sure to check the mark to see whether you
tighten the bolt to the specified angle or not.
3. Draw lines on the surface of the parts you tighten:
If you fail this, you may tighten the bolt by the
the lines which pass through the bolt’s center (A —
angle method again by accident and damage the
B: bolt side) (C — D: parts side) and the line at the
bolt. Take extreme care.
specified tightening angle from the bolt’s center (E
— F). Important:
• Follow the instructed order to tighten bolts.
• Do not retighten if you tighten by the angle
method.
Bolt angle gauge (5-8840-0266-0), the tool for tighten-

ing bolts by the angle method, is set.
A B C D Special tool classification

A; Essential tool
1
Servicing operation cannot be done with any other
E
tools than the essential tool.
F B; Recommend tool
Servicing work can be done with a general-purpose
tool commercially available. However, it is advisable to
use the recommended tool as much as possible for a
WSLE0008
reduced work time and an improved safety in work
Name operations.
1. Specified Tightening Torque
C; Available tool
4. Tighten the bolt with wrench until the line on the Although it takes a more working time, servicing opera-
bolt (A — B) aligns with the specified angle line (E tions can be made with a tool commercially available as
— F on the surface of the parts). substitute for the available tool.
Recommended Lubricant
Engine oil
Use the engine oil below.
Engine oil grade
Engine classification Engine oil grade (API service category)

With turbocharger CD or CF-4
* (CE, CF, CH-4, CI-4 or CI-4 Plus)
* mark may vary depending on each machine. Refer to the machine manufacturer specification.
ISUZU genuine engine oil

Besco Super: CC
Besco S — 3: CD
Besco Multi Z: CD
Engine oil viscosity chart
ENGINE OIL VISCOSITY GRADE – AMBIENT TEMPERATURE
SAE 5W-20
[Single grade] SAE 20, 20W SAE 40
SAE 10W SAE 30
Ambient -25 C -20 C -15 C -0 C 15 C 25 C 30 C

temperature (-13 F) (-4 F) (5 F) (32 F) (59 F) (77 F) (86 F)
SAE 10W-30
[Multi grade]
SAE 15W-40, 20W-40
WSLE0034
The engine oil affects the startability, driving performance, oil consumption, wear of the sliding part, and seizure,
depending on the viscosity. You should select the engine oil depending to a temperature and the chart above.
Engine oil level

4LE2X model: Approx. 9.3 — 12.1 L {9.8 — 12.8 qts}
Note:
Engine oil level may vary depending on the machine
specification.
List of Trouble Symptom
Engine does not start
Engine does not start
Starter does not run Starter runs but does Engine starts but
not start does not run
continuously.
Check battery
Engine Fuel system Fuel injected Air mixed in

(*2)
Battery in OK fuel pump
discharging Check
(Charge) compression
(*) No fuel Fuel injected
pressure
injected
Retighten, OK
Check wiring
replace
Check if fuel Check OK packing,
Low OK comes preheating bleed air
Loosened OK compression to fuel pump circuit
connector or pressure
broken wire
(Retighten or Check for air
replace with Defective mixing Poor Normal Disordered
new wiring) valve, spring, operation operation idling
gasket, etc. of glow of glow
(Overhaul) plug plug
Air mixed OK control control
Check starter switch resistance resistance
(Retighten it,
replace (Replace) OK
packing, bleed
air) OK
Defective OK Adjust
(Replace) Check idling
injection
Check fuel timing
filter (*2)
Check magnetic
switch Abnormal OK Check for the
(Adjust) stuck EGR valve
Clogged OK
(opened position)
(*) (Clean)
(*3)
Defective OK Check nozzle
(Replace)
Check engine stop Replace the EGR OK
solenoid return cut solenoid and
Defective OK
(Repair or valve case by
Check starter bush replace) the set
Check solenoid
(*3) Refer to "EGR Control"

OK Defective injection
Poor contact in the Exhaust System
Stuck solenoid or OK pump (Bring
(Repair or section.
poor operation it to a specialty
replace)
(Repair or replace) shop for repair)
Defective starter Note: "Bring it to a specialty shop" means that defective parts of the injection pump
(Bring it to a specialty and electricals must be brought to a specialty shop for repair. (This note is
shop for repair) applicable to all the following procedures.)
WSLE0192
Engine speed lacks smoothness
Unstable engine rotation
Unstable engine Idling speed Unstable rotation at Unstable rotation at Engine does not
idling too high medium speed high speed change from high to
(Hunting) low rotation
Defective idling Defective control Governor spring Check fuel for air Check accelerator
adjustment lever adjustment deteriorated mixing pedal
Defective OK Defective OK Air mixed OK Pedal OK

valve return (Repair or (Bleed air) sticking or
(Adjust) replace) hitching
(Clean or
replace)
Check high pressure Defective injection Check fuel pipe for Check fuel filter for
pipe for cracking, pump (Bring it to a crash clogging
clogging or bending specialty shop for Defective injection
repair) pump (Bring it to a
specialty shop for
repair)
Crash OK Clogged OK
Cracked, OK (Replace) (Clean or
clogged or replace)
bent
(Replace)
Check uneven fuel

injection
Check nozzle
Uneven OK
Defective OK
(Adjust)
(Repair or
replace)
Check valve clearance

Check cylinder for adjustment
uneven compression
pressure
Poor OK
adjustment
Uneven OK (Adjust)
compression
pressure
(Adjust)
Defective injection
pump (Bring it to a
specialty shop for
Defective injection repair)
pump (Bring it to a
specialty shop for
repair)
WSLE0193
Output shortage
Insufficient output
Fuel system Mechanical There is insufficient

system torque and a lot of
black smoke at
low-speed
Check fuel for air
mixing Check engine
control Check for the
stuck EGR valve
(opened position)
Air mixed OK (*)
(Bleed air) Poor OK
adjustment
(Adjust) Replace the OK
Check fuel filter EGR cut
or fuel hose for solenoid
clogging and valve
Check inlet air case by
temperature the set
Clogged OK
(Clean or OK Check the fuel
Temperatu
Replace) system and
re too high
(Improve mechanical system
ventilation)
Check high (*) Refer to "EGR Control"
pressure pipe for in the Exhaust System
clogging or section.
bending Insufficient inlet
air
Clogged OK
Air cleaner OK
or bent
(Replace) stained
(Clean or
replace)
Check nozzle
Check valve
clearance and
Defective OK cam lift
(Repair or
replace)
Abnormal OK
(Adjust or
Check injection
replace)
timing
Abnormal OK Check compression

(Adjust) pressure
Low
Defective
injection pump
(Bring it to a
specialized shop
Low
for repair)
Excessive
blow-by Gas leak from
gas valve and gasket
(Overhaul) (Repair or replace)
WSLE0194
Overheat
Overheat
Cooling system Handling
Check cooling Check fan belt Check if oil used

water level for slip is inferior quality,
or engine oil is
too much
Insufficient OK Slipping OK
(Adjust)
Care must OK
be taken
when
Replenish Check Check thermostat replenishing
for (Replace)
leakage
Malfunction OK
(Replace)
Engine Overloaded
Leak to Leak to rotation

external internal too high
Check cooling
system for stain,
and radiator for
Repair or clogging
Repair
replace Temperature
abnormally high
Stained or
clogged
(Clean) OK Improve
ventilation
WSLE0195
Exhaust fault
Abnormal exhaust gas
White smoke too much Black smoke too much Check for the stuck EGR
valve (opened position) (*)
Check if fuel used is of Check fuel for water Check nozzle Air cleaner clogged
inferior quality mixing
Defective (Repair OK Replace air OK Replace the EGR OK

or replace) cleaner cut solenoid and
Change fuel OK Water mixed OK
element valve case by
(Change fuel) the set
Check if engine oil is too Check injection timing Check air hose for crash
much (*) Refer to "EGR Control"
Check injection timing in the Exhaust System
Advanced too much OK section.
OK (Adjust)
Delayed
(Adjust)
Check injection pump

Check compression ratio
Defective injection pump OK

Low OK (Bring it to a specialty
shop for repair)
Gas leak from

Check up and 1. Disordered valve timing
Excessive valve and
down 2. Broken piston ring or
blow-by gas gasket (Repair
movement of oil misassembly
(Overhaul) or replace)
3. Worn camshaft
4. Worn valve or insert
Stuck (Overhaul) (Overhaul)
WSLE0196
Battery over discharge
Over-discharge of battery
Battery Wiring Regulator and generator
Check electrolyte level Check terminals for warp, Check belt for slip or damage
deformation or corrosion
Low OK Slipping or OK
OK damaged (Repair
Poor contact
or replace)
(Repair or replace)
Battery Natural
case consumpt Over
cracked ion charge Test charging condition
(Replace) (Replenish) Check for broken wire
(Repair or replace)
Note: Improper maintenance Abnormal OK
Bring it to a battery shop

Check specific gravity
Low
Recharging
Recharge impossible
Bring it to a battery specialty shop
WSLE0197
Oil pressure is too low Fuel consumption deteriorates
Oil pressure too low Fuel consumption too much
Check oil level Check for fuel leakage
Low (Replenish) OK Leaking (Retighten, OK

replace packing seal)
Check cooling water temperature

Check nozzle
High OK
(See "Overheat") Defective OK
(Repair or replace)
Check oil in crankcase

Check injection timing
Improper OK
viscosity
Abnormal (Adjust) OK
Water or fuel mixed. Check fuel
system and cooling system Check compression ratio
Check relief valve Low OK
Defective OK Defective injection pump

(Repair or replace) (Bring it to a specialty
shop for repair)
1. Oil pump malfunction

2. Loosened or cracked pipe Excessive Gas leak from
3. Wear of sliding part blow-by gas valve and gasket
4. Oil pump clogged (Repair or
(Overhaul) replace)
WSLE0198 WSLE0199
Oil consumption deteriorates
Oil consumption too much
Check for oil leakage
Leaking (Retighten, OK
replace packing seal)
Check oil quality
Poor quality OK
(Change to specified oil)
Check bleeder for clogging
Clogged (Clean) OK
Check up and down movement of oil
1. Oil pump malfunction

2. Loosened or cracked pipe
3. Wear of sliding part (*)
4. Oil pump clogged
5. Defective valve stem seal
(Overhaul)
(*) Worn bore,and worn or broken

ring (Measure compression
pressure, and check entrance of
dust)
WSLE0200
Engine knocking
Engine knocking
Mechanical system Fuel system
Check up movement of oil Check injection timing
Oil stained (Overhaul) OK Abnormal (Adjust) OK
Check compression pressure Check nozzle
Low OK Defective OK
(Repair or replace)
To fuel system
Note: Fuel used is of poor quality.
Excessive Gas leak from

blow-by gas valve and gasket
(Overhaul) (Repair or
replace)
WSLE0201
Repair Standard
1. This table specifies the repair standard for 4LE2X model “ISUZU diesel engine”.
2. This repair standard consists of items to be checked, nominal dimension, assembly specifications, service limit,
and repairing procedure.
• “Nominal dimension” is the standard value at the time of manufacture.
• “Assembly specification” is the target value after repairing (at assembling). It may differ in some degree from
“assembly dimension” of the new engine.
• “Service limit” is the limit value of wear, etc. which must not be exceeded. When it is reached, the part should
be repaired or replaced.
• “Repairing procedure” indicates general methods to repair.
• The unit for the numbers in the table are all “millimeter {inch}” if not otherwise specified.
3. If the whole engine is requested for repair, “check the locations which need to be repaired” first by “the bench
test” or something. Then perform the minimum overhaul. If a part of engine is requested for repair, perform
repairing based on this “repair standard”.
4. This repair standard may be changed in the value, specification, and others without notice due to “design
change” of the engine.
Time to overhaul the engine
Standard
Item to be checked Service limit Repairing procedure Remarks
value
Coolant temperature: 70
— 85°C {158 — 185°F}
Compression pressure of the cylinder Engine speed: approx.
3.04 {441} 2.5 {363}
(MPa {psi}) 250 rpm
Overhaul the engine. Vary depending on alti-
tude.
Fuel consumption rate (L/h) 100 % 140 %
Lubricant consumption rate (L/h) 100 % 200 %
Cylinder block
Item to be checked Standard Service limit Repairing procedure Remarks

value
Wear of the cylinder bore
Perform boring along the
Measurement position: 13 {0.512} φ85.2
φ85 {3.3465} oversize piston, then per-
lower from the top surface of the cyl- {3.354}
form honing.
inder block
Maximum amount of
repaired value; 0.3 {0.012}
0.075
Distortion of upper surface of the cyl- Repair with a surface The total amount of
{0.00295} or 0.15 {0.006}
inder block grinder. repaired values of the cyl-
less
inder head and of the cyl-
inder block.
Water pressure test (three minutes) Repair or replace the one
490 {71}
(kPa {psi}) with water leakage.
Cylinder head

value
IN 0.7 {0.028} 1.2 {0.047} Replace the valve and
Valve seat depression Valve seat angle is 45°
EX 0.9 {0.035} 1.5 {0.059} insert.
Repair with the valve seat Wrap the contact surface

Contact width of the valve seat 2.0 {0.079} 2.5 {0.098}
cutter. sufficiently after repair.
Maximum amount of
repaired value; 0.3 {0.012}
Distortion (flatness) of the under sur- 0.075
Repair with a surface The total amount of
face (installation surface) of the cylin- {0.00295} or 0.15 {0.006}
grinder. repaired values of the cyl-
der head less
inder block and of the cyl-
inder head.
Distortion of exhaust manifold instal- 0.05 {0.002} or
0.2 {0.008} Repair.
lation surface less
Water pressure test (three minutes) Repair or replace the one
490 {71}
(kPa {psi}) with water leakage.
83.4 — 93.2 - Clean the seating sur-
{8.5 — 9.5/ face and thread of the
Tightening torque of M12 × 1.5 61.5 — 68.7} bolt.
the cylinder head bolt: ↓ - Apply engine oil to the
(N⋅m {kgf⋅m/lb⋅ft}) 60° — 90° seating surface and
(Angle method) 24.5 — 34.3 thread of the bolt.
M8 × 1.25 {2.5 — 3.5/ - Never retighten after
18.1 — 25.3} angle method tightening.
Piston

value
Clearance with the cylinder 0.040 — 0.085
Grade position from the top surface: {0.0016 —
54.85 {2.159} 0.0033}
0.004 — 0.017 If significant knocking
Clearance between piston pins and
{0.00016 — sound occurs, replace the
piston pin holes
0.0007} piston pin or the piston.
φ26.970
Wear of the pin φ27 {1.063}
{1.0618}
0.20 — 0.35
Top ring {0.008 —
0.014}
1.5 {0.059}
0.35 — 0.50 Replace piston ring. When
Second
Piston ring end gap {0.014 — overhauling the engine,
ring
0.020} replace the piston ring.
0.20 — 0.40
Oil ring {0.008 — 1.0 {0.039}
0.016}
Piston ring

value
0.085 — 0.105
Top ring {0.0033 — 0.2 {0.008} When assembling the ring to
0.0041} the piston, be sure to
assemble with the mark of
Clearance between 0.050 — 0.085
Second Replace the ring or the the ring facing upward.
the piston ring groove {0.0020 — 0.15 {0.006}
ring piston. Inverse assembly makes oil
and the ring 0.0033}
consumption deteriorate.
0.030 — 0.070 The oil ring is independent
Oil ring {0.00120 — 0.15 {0.006} of top or bottom.
0.00276}
The ring end direction 180° alternate
Connecting rod

value
Play of the small end and the piston
boss between front and back direc- 1.0 {0.039} Reference value
tion (one side)
Extrusion Use the one with extrusion
Tension of the connecting rod bear- 0.055 — 0.085 and tension, and be care-
ing {0.00217 — ful about sticking of rear
0.00330} side.
0.026 — 0.067
Clearance between the connecting Be careful with the preci-
{0.0010 — 0.1 {0.0039} Replace the bearing.
rod bearing and crank pin sion of the crank pin.
0.0026}
Replace the one with
Contact surface of the connecting
defective contact or abra-
rod bearing and crank pin
sion.
0.008 — 0.020 Clearance should be wide
Clearance between the small end Replace the bushing or
{0.00031 — 0.05 {0.002} enough to turn smoothly
bushing and the piston pin the pin.
0.00080} with its big end held.
0.20 — 0.33
Axial play of the connecting rod and
{0.008 — 0.35 {0.014}
the crank pin
0.013}
Center distance between the big end
133.5 {5.256} Reference value
and small end
Torsion of holes on the big end and
0.05 {0.002} or
small end (L = per 100 mm {3.937 0.2 {0.008} Repair or replace.
less
in})
Parallelism of holes on the big end
0.05 {0.002} or
and small end (L = per 100 mm 0.15 {0.006} Repair or replace.
less
{3.937 in})
23 — 26 {2.3 Apply engine oil to the
Tightening torque of the bearing cap — 2.7/17.0 — thread of the bolt and the
bolt (N⋅m {kgf⋅m/lb⋅ft}) 19.2} → 100° seating surface of the nut,
— 115° and tighten.
Crankshaft

value
Uneven wear of the journal and the
0.05 {0.002} Replace the crankshaft.
pin
0.14
Wear of the journal φ60 {2.362} Replace the crankshaft.
{0.0055}
Wear of the pin φ46 {1.811} 0.13 {0.005} Replace the crankshaft.
0.007
{0.00028} for
Finishing precision of the journal and
both ellipse
the pin (taper and ellipse)
and taper
Extrusion Use the one with extrusion

0.02 — 0.06 and tension, and be care-
Tension of the journal bearing
{0.0008 — ful about sticking of rear
0.00236} side.
0.029 — 0.072
Clearance between the journal and 0.11
{0.0011 — Replace the bearing.
the bearing {0.0043}
0.0028}
0.058 — 0.208 Measure at the front of the
Replace the thrust bear-
Axial play of the crankshaft {0.0023 — 0.3 {0.012} thrust in No.2 journal por-
ing.
0.0082} tion of the crankshaft.
0.025
Crankshaft runout {0.00098} or 0.05 {0.002} Replace.
less
Chamfer the warped ones
Ring gear and replace the remark-
ably damaged ones.
0.20
Balance of the crankshaft (N⋅cm Check the dynamic bal- (Reference value) At both
{20/ 0.2778} or
{gf⋅cm/on⋅in}) ance. ends of the journal
less
Apply engine oil to the Be sure that there is no
83.4 — 93.2
Tightening torque of the crank bear- thread and the seating scratch or foreign object
{8.5 — 9.5/
ing cap bolt (N⋅m {kgf⋅m/lb⋅ft}) surface of the bolt, and pinched on the bearing
61.5 — 68.7}
tighten. cap match surface.
Be careful with the oil seal
Wear of the oil seal in the crankshaft Replace the oil seal when
collapsed. (Apply oil suffi-
rear part there is oil leakage.
ciently before assembly.)
Camshaft

value
Repair or replace the cam-
Uneven wear of the center journal 0.05 {0.002}
shaft.
φ51.92
Wear of the center journal φ52 {2.047} Replace the camshaft.
{2.044}
0.02 {0.0008}
Camshaft runout 0.1 {0.0039} Replace the camshaft.
or less
Inlet 6.13 {0.241} 5.83 {0.230} Repair light stepped wear
Height of the cam Replace the camshaft.
Exhaust 6.43 {0.253} 6.13 {0.241} of the cam.
Timing gear

value
Crank gear/Idle
0.04 {0.0016} 0.2 {0.008}
Backlash of the gear
Replace the gear.
timing gear Idle gear/Cam-
0.03 {0.0012} 0.2 {0.008}
shaft gear
−0.004 —
Clearance between the crank gear +0.050
and the crankshaft {−0.00016 —
+0.0020}
Clearance between the camshaft 0 — 0.042
gear and camshaft {0 — 0.0017}
0.025 — 0.085
Clearance between the idle gear Replace the idle gear or
{0.00098 — 0.2 {0.008}
bushing and shaft the shaft.
0.00330}
Uneven wear of the idle gear shaft 0.1 {0.0039} Replace the gear shaft.
0.058 — 0.115
Play between front and back direc-
{0.0023 — 0.2 {0.008} Replace the thrust collar.
tion of the idle gear
0.0045}
Valve
Standard
value
φ6.85
Wear of the inlet valve stem φ7 {0.276} If the valve should be
{0.270} replaced due to wear of
Replace the valve.
φ6.80 the valve seat, also
Wear of the exhaust valve stem φ7 {0.276} replace the valve guide.
{0.268}
0.023 — 0.056
Clearance between the inlet valve
{0.0009 — 0.2 {0.008}
stem and valve guide
0.0022} Replace the valve or valve
0.030 — 0.063 guide.
Clearance between the exhaust 0.25
{0.0012 —
valve stem and valve guide {0.0098}
0.0025}
Interference of the valve guide and Apply oil to the valve
0.023 {0.0009}
cylinder head guide and press-fit.
Thickness of IN 1 {0.039} 0.7 {0.028}

Replace the valve.
valve EX 0.8 {0.031} 0.5 {0.020}
Height of the valve guide from the
9.5 {0.374} Reference value
cylinder head
Be careful not to damage
Lip of the valve stem oil seal φ6.5 {0.256} φ6.8 {0.268} Replace oil seal
the lip.
Tension (N {lb})
(When compressed
167 {38} 147 {33}
to installing length
29.9 mm {1.177 in})
Valve spring Replace the valve spring.
Free height 42.1 {1.657} 40.0 {1.575}
1.8 {0.071} or
Squareness 2.5 {0.098}
less
0.35 — 0.45
Valve clearance; inlet and exhaust
0.40 {0.016} {0.014 — Adjust.
(at cold condition):
0.018}
Repair light stepped wear
Contact surface of the valve stem Replace if there is exces-
and damage with the oil
end and the rocker arm sive wear or damage.
stone.
0.005 — 0.045
Clearance between the rocker arm Replace the rocker arm or
{0.0002 — 0.2 {0.008}
and the rocker arm shaft the shaft.
0.0018}
φ11.85
Wear of the rocker arm shaft φ12 {0.472} Replace.
{0.467}
0.3 {0.012}
Bend of the push rod Replace.
or less
Tappet
Standard
value
0.020 — 0.054
Clearance between the tappet and
{0.0008 — 0.1 {0.0039} Replace the tappet.
the cylinder block
0.0021}
φ20.97 —
φ20.92
Wear of the tappet 20.98 {0.8256 Replace the tappet.
{0.824}
— 0.8260}
Contact surface of the tappet and the Replace if there is exces- Repair light damage with
cam sive wear or deformation. the oil stone.
Air cleaner
Standard
value
Machine manufacturer
Condition of the air cleaner element
arrangement parts
Water pump

value
0.008 — 0.010
Play of the water pump ball bearing
{0.00031 — 0.2 {0.008} Replace.
(radius direction)
0.00040}
Discharge amount (L/min)
(pump speed 2,800 rpm
76
Coolant temperature is normal.
Maximum lift 0.035 MPa {3.5 m⋅Aq})
With two belts:
approx. 7.5 —
8.5 {0.295 —
0.335}
Deflection of the fan belt Adjust. (Reference) 98 N {22 lb}
With one belt:
approx. 5.5 —
6.0 {0.217 —
0.236}
Thermostat working start tempera- Replace the thermostat if
82°C {180°F}
ture (at barometric pressure) its working is incomplete.
The temperature when
Thermostat full-open temperature (at
95°C {203°F} thermostat lift amount is
barometric pressure)
9.5 mm {0.374 in} or more
Fuel feed pump
Standard
value
0.8 or more 0.3 Repair or replace.
At 11.8 kPa {1.7 psi}
Be sure that
Repair or replace when
Airtight (98.1 kPa {14.2 psi}) there is no
there is leakage.
leakage.
Injection pump
Adjustment conditions
Pump part number 89-7229-3680 Remarks

Revolution direction Clockwise (viewed from drive-end)
105780-0060
Nozzle
NP-DNOSD1510
Nozzle holder ASM 105780-2150 (BOSCH minimus)
Nozzle opening pressure (MPa {psi}) 13.0 {1885}
Oil feed pressure (MPa {psi}) 0.05 {7.3}
Pipe
Outside diameter × inside diameter × φ6 {0.236} × φ2 {0.079} × 450 {17.717}
length (mm {in})
Inspecting oil JIS No.2 diesel fuel
Oil temperature °C {°F} 35 — 40 {95 — 104}
Injection amount adjustment
Rack position Pump Average injection amount

Adjustment point Remarks
(mm) speed (rpm) (mm3/stroke)
A a = 8.2 {0.323} 1,300 12.0 ± 0.3 Standard
B a + 1.0 {0.039} 400 *(10) Standard
* ( ) for reference value
Generator (24V30A Mitsubishi Electric)

value
Shaft bend Replace the rotor.
Turn it by hand and check
Play of bearing Replace the bearing. that it rotates smoothly
and has no noise or play.
Outside diameter of the slip ring 22.7 {0.894} 22.1 {0.870} Replace the rotor.
Repair with a sand paper
Slip ring surface dirty or the like if there is dirt or
damage.
Brush length Repair when the following
18.5 {0.728} 5.0 {0.197}
(amount of occurs: the spring contact
(10.0 {0.394}) (1.5 {0.059})
extrusion) surface of the brush is
incomplete, the brush
Brush and brush spring pressure is not
spring even or not appropriate,
Tension 4.8 — 6.0 2.2 the brush is excessively
N {lb} {1.08 — 1.35} {0.49} worn or chipping, support-
ing degree of the brush
holder is not appropriate.
Output current (27 V 1,800 r/min) 18 A or more 18 A or less Replace.
28 or less, or
Regulated voltage by regulator (V) 28.5 Replace the regulator.
29 or more
Generator (24V50A Nikko Electric)

value
24.996 —
25.005 24.95
Wear of the shaft (front) Replace the rotor.
{0.9841 — {0.982}
0.9844}
16.996 —
17.012 16.95
Wear of the shaft (rear) Replace the rotor.
{0.6691 — {0.667}
0.6698}
Turn it by hand and check
Play of bearing Replace the bearing. that it rotates smoothly
and has no noise or play.
Output current (27V 5000rpm) 50 A or more 50 A or less
Regulated voltage by regulator (V) 27.5 — 29.5 Replace the regulator.
Starter (24V3.2kW Mitsubishi Electric)

value
Wear of the outside diameter of com-
32 {1.26} 31.4 {1.236} Replace.
mutator
Uneven wear of the outside diameter 0.1 {0.0039}
— Replace.
of commutator or more
0.5 — 0.8
Depth of mica between commutator 0.2 {0.008}
{0.020 — Repair or replace.
segments or less
0.031}
Brush length 17.5 {0.689} 11 {0.433} Replace.
0.5 — 2.0 2.0 {0.079} Repair or replace if there
Pinion (gap) {0.020 — or more is excessive wear or chip-
0.079} ping.
Rotates smoothly when
the pinion is turned to the
Clutch action — — — drive direction, and locks
when turned to the inverse
direction.
No load test 3,750 r/min or 3,750 r/min
Repair or replace.
Revolution speed (23 V/80 A or less) more or less
12.94 N⋅m
12.94 N⋅m {1.3
Torque {1.3 kgf⋅m Repair or replace.
Load test kgf⋅m}
or less
18.6 V/250 A or less
Revolution 1,550 r/min or 1,550 r/min
Repair or replace.
speed more or less
Restraint test 47.07 N⋅m
47.07 N⋅m {4.8
Load Torque {4.8 kgf⋅m} Repair or replace.
kgf⋅m} or more
8 V/760 A or less or less
Preheating device

value
Replace when there is an
Glow plug open circuit or a short cir-
cuit.
Oil pressure
Standard
value
Lubrication oil pressure kPa {psi} 441 — 490
200 {29}
(at 2,000 rpm) {64 — 71}
Oil pump and relief valve

value
0.100 — 0.185
Clearance between the pump body Replace the bushing,
{0.0039 — 0.4 {0.016}
and outer circle of the outer rotor rotor, or body.
0.0073}
(engine speed 2,700 rpm SAE#30
26.8
discharge pressure 392 kPa {57 psi}
oil temperature 50°C {122°F})
0.040 — 0.085
Axial clearance between the pump Replace the rotor or the
{0.0016 — 0.15 {0.006}
cover and the rotor cover.
0.0033}
Tip clearance between the inner rotor 0.17 {0.0067}
0.2 {0.008} Replace the rotor.
and the outer rotor or less
0.032 — 0.077
Clearance between the drive shaft
{0.0013 — 0.15 {0.006}
and the pump cover
0.0030}
φ21.9
Diameter of the drive shaft φ22 {0.866} Replace the shaft.
{0.862}
Relief valve starting 392 — 490 {57
Oil pump
pressure kPa {psi} — 71}
Complete inspection
Standard
value
Perform for 30 minutes or
“Grinding” drive of the engine
more
Compression pressure of the cylinder
(MPa {psi}) 3.04 {441} 2.5 {363} Repair.
— 85°C {158 — 185°F}
(approx. 250 rpm)
Difference between the compression ±5 % or less to
pressure of the cylinders the average Repair.
— 85°C {158 — 185°F}
(approx. 250 rpm) value
Lubrication oil pressure (kPa {psi}) 441 — 490 {64
(2,200 rpm) — 71}
Output inspection 90 % or more Assume that the actual
performance of the new
Fuel consumption inspection 110 % or less engine is 100 %.
4LE2 Engine Mechanical 1A-1
Engine
4LE2 Engine Mechanical
Table of Contents
ISUZU Diesel Engine ............................................ 1A-2 Crankshaft Rear Oil Seal ....................................1A-73
Service Precautions ........................................... 1A-2 Components.....................................................1A-73
How to Read the Model...................................... 1A-3 Removal ...........................................................1A-74
Explanations on Functions and Operation ......... 1A-3 Installation ........................................................1A-74
Function Check .................................................. 1A-4 Torque Specifications.......................................1A-75
Specifications ................................................... 1A-11 Timing Gear Train ...............................................1A-76
Engine Accessories............................................. 1A-12 Components.....................................................1A-76
Components..................................................... 1A-12 Removal ...........................................................1A-77
Removal ........................................................... 1A-13 Inspection.........................................................1A-77
Installation ........................................................ 1A-14 Installation ........................................................1A-79
Torque Specifications....................................... 1A-16 Torque Specifications.......................................1A-80
Engine Exterior Equipment ................................. 1A-17 Camshaft............................................................. 1A-81
Components..................................................... 1A-17 Components.....................................................1A-81
Removal ........................................................... 1A-20 Removal ...........................................................1A-82
Installation ........................................................ 1A-26 Inspection.........................................................1A-82
Torque Specifications....................................... 1A-35 Installation ........................................................1A-85
Rocker Arm Shaft................................................ 1A-36 Torque Specifications.......................................1A-86
Components..................................................... 1A-36 Crankshaft ...........................................................1A-87
Removal ........................................................... 1A-37 Components.....................................................1A-87
Disassembly..................................................... 1A-37 Removal ...........................................................1A-88
Inspection......................................................... 1A-37 Disassembly.....................................................1A-88
Reassembly ..................................................... 1A-39 Inspection.........................................................1A-89
Installation ........................................................ 1A-40 Reassembly .....................................................1A-91
Torque Specifications....................................... 1A-41 Installation ........................................................1A-91
Cylinder Head ..................................................... 1A-42 Torque Specifications.......................................1A-93
Components..................................................... 1A-42 Cylinder Block .....................................................1A-94
Removal ........................................................... 1A-43 Components.....................................................1A-94
Disassembly..................................................... 1A-44 Removal ...........................................................1A-95
Inspection......................................................... 1A-44 Inspection.........................................................1A-95
Reassembly ..................................................... 1A-49 Installation ........................................................1A-97
Installation ........................................................ 1A-52 Special Tool ........................................................1A-98
Torque Specifications....................................... 1A-53 List of Special Tool...........................................1A-98
Piston, Connecting Rod ...................................... 1A-54
Components..................................................... 1A-54
Removal ........................................................... 1A-55
Disassembly..................................................... 1A-56
Inspection......................................................... 1A-57
Reassembly ..................................................... 1A-61
Installation ........................................................ 1A-62
Torque Specifications....................................... 1A-64
Flywheel .............................................................. 1A-65
Components..................................................... 1A-65
Removal ........................................................... 1A-66
Installation ........................................................ 1A-66
Crankshaft Front Oil Seal.................................... 1A-68
Components..................................................... 1A-68
Removal ........................................................... 1A-69
Inspection......................................................... 1A-70
Installation ........................................................ 1A-70
1A-2 4LE2 Engine Mechanical
ISUZU Diesel Engine

Service Precautions Service precautions specific to this engine
Service precautions about maintenance Holes or clearances in the fuel system, which serve as
a passage of fuel, including the inside of the nozzle
To prevent damage to the engine and ensure reliability
holder, are made with extreme precision. They are
of its performance, pay attention to the following in
therefore highly sensitive to foreign matter and the
maintaining the engine:
entry of foreign matter could cause serious damage.
• When taking down the engine on the ground, do Take extreme care not to allow foreign matter to enter.
not make the bearing surface of the oil pan touch When servicing the fuel system, every precaution must
directly the ground. Use a wood frame, for exam- be taken to prevent the entry of foreign material into the
ple, to support the engine with the engine foot and system.
the flywheel housing.
• Before beginning the service procedure, wash the
Because there is only a small clearance between
fuel line and the surrounding area.
the oil pan and the oil pump strainer, it can dam-
age the oil pan and the oil strainer. • Perform the service procedures with clean hands.
Do not wear work gloves.
• When the air duct or air cleaner is removed, cover
the air intake port to prevent foreign matter from • Immediately after removing the fuel hose and/or
getting into the cylinder. If foreign matter gets in, it fuel pipe, carefully tape vinyl bags over the
can considerably damage the cylinder and others exposed ends of the hose or pipe.
while the engine is operating. • If parts are to be replaced (fuel hose, fuel pipe,
• When maintaining the engine, never fail to remove etc.), do not open the new part packaging until
the battery ground cable. Otherwise, this may installation.
damage the wire harness or electrical parts. If you
need electricity on for the purpose of inspection, Work procedure
for instance, watch out for short circuits and others. • The fuel opening must be quickly sealed when
• Apply engine oil to the sliding contact surfaces of removing the fuel pipe, injection pipe, nozzle
the engine before reassembling it. This ensures holder, and injection pump.
adequate lubrication when the engine is first • The eyebolts and gasket must be stored in a clean
started. parts box with a lid to prevent adhesion of foreign
• When valve train parts, pistons, piston rings, con- matter.
necting rods, connecting rod bearings or crank- • Fuel leakage could cause fires. Therefore, after
shaft journal bearings are removed, put them in finishing the work, wipe off the fuel that has leaked
order and keep them. out and make sure there is no fuel leakage after
• When installing them, put them back to the same starting the engine.
location as they were removed.
• Gaskets, oil seals, O-rings, etc. must be replaced
with new ones when the engine is reassembled.
• As for parts where a liquid gasket is used, remove
an old liquid gasket completely and clean it up
thoroughly so that no oil, water or dust may be
clung to them. Then, apply the designated liquid
gasket to each place anew before assembly.
• Surfaces covered with liquid gasket must be
assembled within 5 minutes of gasket application.
If more than 5 minutes have elapsed, remove the
existing liquid gasket and apply new liquid gasket.
• When assembling or installing parts, fasten them
with the specified tightening torque so that they
may be installed properly.
How to Read the Model
WSLE0353
Name
1. Stamped Engine Number
Explanations on Functions and Operation Cylinder head

Cylinder block The cylinder head is cast-iron and there are two valves
per cylinder. The angular tightening method of the cylin-
The cylinder block is cast-iron with the center distance
der head bolt further increases reliability and durability.
of each bore being equal and is of the highly rigid, sym-
metrical structure with the crankshaft center being the
center.
Crankshaft
The crankshaft which is stamped “N” on the front end
Piston surface is made of tufftride.
The piston is aluminum-alloy and an autothermatic pis-
ton with a strut cast, while the combustion chamber is a
EGR system
round reentrant type. Based on coolant temperature and engine speed, it is
controlled by EGR cut controller to purify exhaust by
recycling part of it.
Its main components include an EGR cut solenoid, an
EGR cooler and various sensors.
Connecting rod cap bolt Function Check
Do not pull out the connecting rod cap bolt from the Inspection/adjustment of valve clearance
connecting rod except when you need to replace it.
To do this work, use the thickness gauge when the
engine is cold.
Nozzle holder
1. Rotate the crankshaft over 360 degrees into a
Multi-hole type nozzle is used for the nozzle holder. proper direction (clockwise), and set the mark
groove of the crank pulley to the TDC mark (cast)
Sedimenter of the timing gear case cover.
Sedimenter gets rid of water by making use of the dif-
ference in specific gravity between diesel oil and water.
Preheating system 1 2
The preheating system consists of the glow plug timer,

the glow plugs and the glow indicator lamp. The pre-
heating system is operated when the engine coolant
temperature is low, and makes the engine easy to start.
Lubrication system
It is an oil filter with full-flow bypass, which uses a
water-cooled oil cooler and oil jet to cool the piston.
WSLE0021
Name
1. TDC Mark
2. Mark Groove
2. Remove the cylinder head cover and check
whether the No.1 cylinder is in the compression
top dead center position or in the exhaust top dead
center position.
The cylinder is in the compression top dead center
position if both intake and exhaust valves are 1
closed. The cylinder is in the exhaust top dead
2
center position if both intake and exhaust valves
are open.
WSLE0020
Name
1. Adjusting Screw
2 2. Lock Nut
1
4. Rotate the crankshaft again into a proper direction,
and set the mark in the same way as 1. after 3. is
completed. Then measure and adjust the clear-
ances of the remaining valves.
WSLE0022
Name CAUTION:
1. Intake of No.1 Cylinder • Rocker arm is die-cast aluminum. So do not
2. Exhaust of No.1 Cylinder over-tighten the rocker arm when tightening the
adjusting screw.
3. Measure the clearance of the valve with ❍ mark or • The load of the used valve spring is low. So do
× mark in the table, depending on the status of the not push down the spring when measuring or
No.1 cylinder. If the clearance is not the standard adjusting the clearance.
value, adjust it to the standard value using the
adjusting screw. Adjustment table
CAUTION: Cylinder No. 1 2 3 4

To measure the clearance, use the thickness gauge Valve arrange- IN EX IN EX IN EX IN EX
when the engine is cold. ment
No.1 cylinder
Valve clearance standard mm {in} compression
❍ ❍ ❍ ❍
value top dead center
position
Inlet valve 0.40 ± 0.05 {0.016 ± 0.002}
No.1 cylinder
Exhaust valve (at cold condition)
exhaust top
× × × ×
dead center
position
Inspection and adjustment of injection timing
1. Remove the No.1 cylinder injection pipe.
2. Then remove the delivery valve holder of the No.1 1 2
cylinder injection pump, and pull out the delivery
valve and the delivery spring.
4
1
WSLE0021
Name
1. TDC Mark
2. Mark Groove
6. Adjust injection timing by the shim between the

WSLE0026
injection pump and the cylinder block.
Name The following nine types of identifying symbols are
1. Delivery Valve Holder stamped (or sealed) on the shim.
2. Delivery Spring
3. Delivery Valve The identifying symbols and thickness mm {in}
4. Injection Pump of the shim
Symbol Thick- Symbol Thick- Symbol Thick-
3. Install the delivery valve holder and tighten it, leav- ness ness ness
ing the delivery valve and spring removed.
2 0.2 5 0.5 8 0.8
Tightening torque: {0.008} {0.020} {0.031}
39.2 — 44.1 N⋅m {4.0 — 4.5 kgf⋅m/28.9 — 32.5
lb⋅ft} 3 0.3 6 0.6 10 1.0
{0.012} {0.024} {0.039}
4. Turn the starter switch to the drive position with the
4 0.4 7 0.7 12 1.2
lever of the sedimenter in the open position. Then
{0.016} {0.028} {0.047}
rotate the crankshaft slowly feeding fuel by the
electromagnetic pump, the gap with the fuel tank,
the feed pump lever, etc. And when the fuel stops CAUTION:
flowing from the delivery holder and bulging at the Adjust the shims for each injection pump of four
dent on top, stop the crankshaft rotating. cylinders at the same time.
Note: Note:
Take extreme care to rotate the crankshaft as slowly as If the shim is thickened by 0.1 mm {0.0039 in}, the
possible and not to miss the position where the fuel injection timing is delayed for approx. 0.6 degree, and if
stops bulging. thinned by 0.1 mm {0.0039 in}, put forward for approx.
0.6 degree.
5. Check the degree in the timing mark on the timing
gear case where the mark groove of the crank pul-
ley is positioned in above 4. status.
Adjust if the value is out of the standard value of
the injection timing.
* Injection timing BTDC 2°
Note:
Injection timing varies depending on the machine spec-
ification.
1
1
2 2
3
5
3
4
WSLE0027 WSLE0159
Name Name
1. Injection Pump 1. Injection Pipe
2. Cylinder Block 2. Nozzle Holder
3. Shim 3. Injection Pump
4. Knock Hole
5. Identifying Symbol
Inspection of compression pressure
7. Assemble removed delivery valve to the injection 1. Warm-up the engine.
pump after cleaning, and tighten the delivery
2. Disconnect the battery cable from the negative ter-
holder to the specified torque.
minal and remove all the glow plugs.
Tightening torque: 3. Disconnect the wire connector of the solenoid for
39.2 — 44.1 N⋅m {4.0 — 4.5 kgf⋅m/28.9 — 32.5 engine stopping.
lb⋅ft}
4. Install the battery cable to the negative terminal.
CAUTION: 5. Install an adapter and a gauge of a compression
Be careful with dirt getting inside when removing gauge (special tool).
and installing the delivery valve or spring. Special tool
Compression gauge (with adapter)
8. Install the injection pipe to the injection pump and 5-8840-2675-0
the nozzle holder, and tighten it with the sleeve Adapter
nut. 5-8840-9029-0
a. Screw the thread portion of the sleeve nut two
or three turns by your hand.
b. Hold the delivery valve holder of the injection
pump with a wrench and tighten the sleeve nut
securely.
Tightening torque:
14.7 — 24.5 N⋅m {1.5 — 2.5 kgf⋅m/10.8 — 18.1
lb⋅ft}
Important:
If over-tightening the delivery valve holder, the rack
cannot move smoothly as the plunger and the
housing are compressed. Therefore, when tighten-
ing the sleeve nuts of the injection pipe, hold the
delivery valve holder with a wrench to prevent
corotation.
Injection nozzle
Use the nozzle tester to check the injecting condition.
1 WARNING:
Do not put hands close to the nozzle hole area
when checking.
Diesel oil may permeate to your body and cause
2
blood poisoning due to high pressure injection.
WSLE0029
Name
1. Compression Gauge
2. Adapter
6. Turn the starter until the indicator of compression

gauge becomes stable and measure the compres-
sion pressure.
Compression pressure (250 rpm) MPa {psi} WSLE0033
Standard value Service limit Difference between cyl-

inders Injecting condition
3.04 {441} 2.5 {363} ±5 % or less to the

Judge the nozzle condition by injecting condition.
average value
1 2 3
WSLE0032
Name
1. Good
2. Defective (fine or clogged)
Perform the measurement described above for all
3. Defective (dropping)
cylinders. If the compression pressure is the ser-
vice limit or less, overhaul the engine.
Note:
CAUTION: • Do not overhaul the engine as a two-step valve
• Be sure to measure for all cylinders. pressure nozzle is adapted to this engine.
• Be sure to use the full-charged battery to main-
tain the engine speed of 250 rpm or more.
• If a overhaul of the nozzle and inspection and
adjustment of the injection pressure are required,
contact a BOSCH service center.
Bleeding air from fuel system

In case of automatic air bleed system
Turn the starter switch to the drive position. The elec- 1
tromagnetic pump operates, the fuel is pressure-fed to 2
the fuel pipe and the leak-off pipe, and the air in the fuel
system is automatically bled out.
In case of other than automatic air bleed system

Bleed air from the fuel pipe eyebolt of the No.1 cylinder 3
injection pump, the leak-off pipe eyebolt of the injection
nozzle, and the air bleed plug of the fuel filter in the
order from the part installed to lower portion, feeding
the fuel by the electromagnetic pump, the gap with the
fuel tank, the feed pump lever, etc. TSHK0106
Name
1. Electromagnetic Pump
2. + Terminal
3. - Terminal
3. Blow air into the inlet of the electromagnetic pump

with your mouth.
• The internal seal may be stuck. Blow air to elim-
inate sticking.
WSLE0028
Name
1. Injection Pump
1
Electromagnetic pump inspection procedure

1. Turn the key switch to ON, and check for pulsation
in the fuel hose.
• It is normal if pulsation exists.
TSHK0107
2. Disconnect the electromagnetic pump connector,
Name
and connect 24V power supply to the electromag-
1. Fuel Inlet Port
netic pump side to check if the pump operates.
2. Fuel Outlet Port
• If it operates properly, there may be open cir-
cuit, short circuit or poor contact in the 4. Install the removed parts, and check again from
machine-side harness. Repair the faulty part, Step 1.
and check again from Step 1.
• If the electromagnetic pump does not operate,
replace the pump.
Fan belt Adjustment procedure
Tension inspection 1. Loosen the adjusting plate which fixes the genera-
Push between the fan pulley and the generator pulley tor, and the mounting bolt of the generator.
with your finger (about 98 N {22 lb}). If the deflection is 2. Adjust the adjusting bolt to the standard value and
out of the standard value, adjust the belt tension. fix the generator at this position.
Be sure to tighten the mounting bolts which you
Deflection mm {in} have loosened.
Standard With two belts: approx. 7.5 — 8.5 {0.295 —
Note:
value 0.335}
With one belt: approx. 5.5 — 6.0 {0.217 — Recheck the tension of the belt after fixing the genera-
0.236} tor since the tension varies in some degree when the
generator gets fixed.
Tightening torque:
Upper part of the generator: 18.6 — 28.4 N⋅m {1.9
— 2.9 kgf⋅m/13.7 — 20.9 lb⋅ft}
Lower part of the generator (24 V-30 A) : 18.6 —
28.4 N⋅m {1.9 — 2.9 kgf⋅m/13.7 — 20.9 lb⋅ft}
1 Lower part of the generator (24 V-50 A) : 41.2 —
55.0 N⋅m {4.2 — 5.6 kgf⋅m/30.4 — 40.6 lb⋅ft}
Adjusting plate: 18.6 — 28.4 N⋅m {1.9 — 2.9 kgf⋅m/
13.7 — 20.9 lb⋅ft}
2
5 1
3
WSLE0025
Name
1. Fan Pulley
2. Deflection
3. Generator Pulley
4. Crank Pulley 2
5. Fan Belt
3 WSLE0204
Name
1. Nut
2. Adjusting Bolt
3. Mounting Bolt
Specifications
Engine name
4LE2X
Item
Engine structure type 4-cycle, water cooled-type, inline four-cylinder, OHV type
Cylinder number − bore × stroke (mm {in}) 4 − 85{3.35} × 96{3.78}
Total displacement (L {cu⋅in}) 2.179 {133}
Compression ratio 18.3:1
Combustion chamber type Direct injection
Overall length × overall width × overall height * 756.3{29.78} × 557{21.93} × 747.3{29.42}
(mm {in})
Dry weight (kg) * 210
Firing order 1—3—4—2
Fuel injection timing (BTDC) (at stop) * 2°
Compression pressure (MPa {psi}) 3.04 {441} / 250 rpm
Intake 0.40 {0.016}
Valve clearance (at cold condition) air
(mm {in})
Exhaust 0.40 {0.016}
Open (before top 15°
Intake dead center)
valve Closed (after bot- 29°
Opening/clos- tom dead center)
ing period of
valve Open (before bot- 40°
Exhaust tom dead center)
valve Closed (after top 16°
dead center)
Injection pump type Bosch type, PFR1KZ model, four
Governor type Centrifugal type, all speeds controlled
Nozzle type Multi-hole type (KBDL model)
Injection pressure (MPa {psi}) * First step: 16.7 {2422}
Second step: 25.0 {3626}
Fuel type Diesel (JIS K2204)
Cooling method Forced circulation, water cooling pressurization type
Cooling fan * φ500 × 8 pieces
Coolant amount (L {qts}) Approx. 4.3 {4.5} (Engine only)
Lubrication oil amount: total (L {qts}) * Approx. 12.1 {12.8} at MAX, 9.3 {9.8} at MIN
Lubricant type (API service category) CD or CF-4
* (CE, CF, CH-4, CI-4 or CI-4 Plus)
Generator output (V — A) * 24 — 30 (Mitsubishi)
* 24 — 50 (Nikko)
Starter output (V — kW) * 24 — 3.2
Recommended battery (rating) 95D31R 64 (five hour rating), the machine manufacturer arrangement
Caution: This specification may be changed partially without notice.

* mark may vary depending on each machine. Refer to the machine manufacturer specification.
Engine Accessories
Components
1
5
4
3
2
1 10
WSLE0312
Name
1. Cooling Fan 6. Fan Belt
2. Fan Clutch 7. Starter
3. Fan Clutch Set Plate 8. Adjusting Plate
4. Spacer 9. Generator
5. Fan Pulley 10. Generator Bracket
Removal • Remove the bolts, and remove the cooling fan
and the spacer. (Without the fan clutch)
1. Remove the cooling fan.
• Remove the nuts and remove the cooling fan
from the fan clutch set plate. (With the fan
clutch) 2
• Remove the nuts and remove the fan clutch
from the cooling fan. (With the fan clutch) 3
• Remove the bolts and remove the fan clutch set

plate and the spacer. (With the fan clutch)
4
3
5
2
1
WSLE0345
Name
1. Cooling Fan
2. Spacer
3. Fan Belt
1 2. Loosen the mounting bolts of the generator and of

the adjusting plate, loosen the belt tension, and
WSLE0208 remove the fan belt.
Name 3. Remove the mounting bolts of the fan pulley, and
1. Cooling Fan remove the fan pulley from the water pump.
2. Fan Clutch 4. Remove the generator together with the adjusting
3. Fan Clutch Set Plate plate.
4. Spacer
5. Fan Belt
2
3
WSLE0209
Name
1. Fan Pulley
2. Adjusting Plate
3. Generator
5. Remove the generator bracket.

6. Remove the starter.
Installation
1. Install the starter to the flywheel housing and
tighten to the specified torque.
Tightening torque:
93.2 — 113 N⋅m {9.5 — 11.5 kgf⋅m/68.7 — 83.3 1
lb⋅ft}
2
WSLE0166
Name
1. Water Pump
1 2. Adjusting Plate
3. Generator
4. Install the fan pulley to the water pump and tighten

WSLE0165
two positions.
Name Tightening torque:
1. Starter 7.8 — 11.8 N⋅m {0.8 — 1.2 kgf⋅m/5.8 — 8.7 lb⋅ft}
5. Install the fan belt to each pulley.
2. Install the generator bracket.
Tightening torque:
M8 bolt: 18.6 — 28.4 N⋅m {1.9 — 2.9 kgf⋅m/13.7 —
20.9 lb⋅ft}
M10 bolt: 41.2 — 55.0 N⋅m {4.2 — 5.6 kgf⋅m/30.4
— 40.6 lb⋅ft} 1
3. Install the generator.
a. Temporarily install and tighten the adjusting
plate with the water pump.
b. Install the lower side of the generator to the
2
generator bracket and temporarily tighten the
bolts and nuts.
c. Install the mounting bolt to the upper part of the 3
generator through the adjusting plate. (Tempo-
rarily tighten)
WSLE0167
Name
1. Fan Pulley
2. Water Pump
3. Fan Belt
6. Adjust the tension of the fan belt.
Move the generator installation position outside,
adjust the belt deflection to the specified value,
4
and tighten the generator and the adjusting plate.
mm {in} 3
Deflection (Push between With two belts: approx. 7.5 2

the pulleys by 98 N {22 lb}) — 8.5 {0.295 — 0.335} 1
With one belt: approx. 5.5 —
6.5 {0.217 — 0.236}
Tightening torque:
Upper part of the generator: 18.6 — 28.4 N⋅m {1.9
— 2.9 kgf⋅m/13.7 — 20.9 lb⋅ft}
28.4 N⋅m {1.9 — 2.9 kgf⋅m/13.7 — 20.9 lb⋅ft}
55.0 N⋅m {4.2 — 5.6 kgf⋅m/30.4 — 40.6 lb⋅ft}
WSLE0169
Adjusting plate: 18.6 — 28.4 N⋅m {1.9 — 2.9 kgf⋅m/
13.7 — 20.9 lb⋅ft} Name
1. Cooling Fan
2. Fan Clutch
3. Fan Clutch Set Plate
4. Spacer
• Assemble the spacer and install the cooling fan.

(Without the fan clutch)
Tighten this part to the torque according to the
tightening torque specification table in this
workshop manual. (Find the torque value
{medium value — upper limit} depending on a
screw size against the symbols on the bolt
head.)
1 2
WSLE0168
7. Install the cooling fan.

• Install the fan clutch set plate and the spacer.
(With the fan clutch)
Tightening torque:
18.6 — 28.4 N⋅m {1.9 — 2.9 kgf⋅m/13.7 — 20.9
lb⋅ft}
• Install the fan clutch to the cooling fan.
Tightening torque:
18.6 — 28.4 N⋅m {1.9 — 2.9 kgf⋅m/13.7 — 20.9
lb⋅ft}
WSLE0346
• Install the cooling fan to the fan clutch set plate. Name
(With the fan clutch) 1. Cooling Fan
Tightening torque: 2. Spacer
18.6 — 28.4 N⋅m {1.9 — 2.9 kgf⋅m/13.7 — 20.9
lb⋅ft}
Torque Specifications
N m (kg m / lb ft)
7.8 - 11.8 (0.8 - 1.2 / 5.8 - 8.7)
18.6 - 28.4 (1.9 - 2.9 / 13.7 - 20.9)
93.2 - 113 (9.5 - 11.5 / 68.7 - 83.3)
18.6 - 28.4 (1.9 - 2.9 / 13.7 - 20.9)
41.2 - 55.0 (4.2 - 5.6 / 30.4 - 40.6)

7.8 - 11.8 (0.8 - 1.2 / 5.8 - 8.7)
18.6 - 28.4 (1.9 - 2.9 / 13.7 - 20.9)
24V - 30A : 18.6 - 28.4 (1.9 - 2.9 / 13.7 - 20.9)

18.6 - 28.4 (1.9 - 2.9 / 13.7 - 20.9)
24V - 50A : 41.2 - 55.0 (4.2 - 5.6 / 30.4 - 40.6)
WSLE0301
Engine Exterior Equipment

Components
3 4 5 6 7
11
10
WSLE0035
Name
1. Water Pump 7. EGR Cooler Inlet Pipe
2. Water Pump Outlet Pipe (Thermostat) 8. Turbocharger
3. Exhaust Manifold 9. Oil Level Gauge
4. Cylinder Head Cover 10. Turbocharger Oil Return Pipe
5. Air Inlet Pipe 11. Turbocharger Oil Feed Pipe
6. Intake Chamber
1 2 3 4
9 5
WSLE0036
Name
1. Injection Pipe 6. Injection Pump Housing Cover
2. Leak-off Pipe 7. Oil Cooler
3. Fuel Pipe 8. Solenoid ASM
4. Fuel Hose 9. EGR Cooler Bracket
5. Injection Pump
4 3 2 1
WSLE0359
Name
1. PCV Valve 4. EGR Cooler Outlet Pipe
2. Orifice Plate 5. EGR Cut Solenoid
3. Valve Case 6. EGR Cooler
Removal 4. Remove the connector of the EGR cut solenoid,
and remove the orifice plate, the valve case and
1. Disconnect the drain plug of the oil pan and drain
the EGR cut solenoid.
the engine oil.
2. Loosen the water drain cock on the cylinder block
to drain the coolant remaining in the engine.
2 3
WSLE0333
2 Name
1
1. EGR Cut Solenoid
WSLE0207
2. Valve Case
Name 3. Orifice Plate
1. Drain Plug (Oil) 4. EGR Cooler Outlet Pipe
2. Drain Cock (Coolant)
5. Remove the EGR cooler water inlet hose and the
3. Remove the EGR cooler outlet pipe. outlet hose.
Note: 6. Remove the EGR cooler.
After removing the pipe, seal so that foreign matter
Note:
does not enter.
After removing the EGR cooler, seal so that foreign
matter does not enter.
7. Remove the EGR cooler bracket from the cylinder

head.
8. Remove the rear hanger from the EGR cooler 12. Remove the turbocharger ASM from the exhaust
bracket. manifold.
3 3
2
5 4
WSLE0334 WSLE0336
Name Name
1. EGR Cooler Water Inlet Hose 1. Turbocharger Oil Return Pipe
2. EGR Cooler 2. Turbocharger Oil Feed Pipe
3. EGR Cooler Water Outlet Hose 3. Turbocharger
4. Rear Hanger 4. Exhaust Adapter
5. EGR Cooler Bracket
13. Remove the PCV valve from the intake chamber.
9. Remove the EGR cooler inlet pipe. 14. Remove the air inlet pipe from the intake chamber.
Note: 15. Remove the intake chamber from the cylinder
After removing the pipe, seal so that foreign matter head.
does not enter. 16. Remove the mounting bolts (M6×1.0, 15 bolts) of
the head cover, and remove the head cover
together with the gasket from the cylinder head.
• Remove the baffle plate from the cylinder head
cover.
WSLE0335
Name
1. EGR Cooler Inlet Pipe
10. Remove the turbocharger oil feed pipe and the

return pipe.
11. Remove the exhaust adapter from the turbo-
charger.
17. Remove the mounting bolts and nuts of the
exhaust manifold, and remove the manifold and
the gaskets.
2
1 2
1
3
3
4 4
6 WSLE0211
7 Name
1. Thermostat
WSLE0210 2. Water Outlet Pipe
Name 3. Packing
1. PCV Valve 4. Water Pump
2. Intake Chamber
3. Cylinder Head Cover 20. Loosen the sleeve nuts on the nozzle holder side
4. Air Inlet Pipe and on the injection pump side and remove the
5. Gasket injection pipe.
6. Exhaust Manifold
7. Gasket Important:
18. Disconnect the water outlet pipe and pull out the cannot move smoothly as the plunger and the
thermostat. housing are compressed. Therefore, when loosen-
19. Remove the water pump from the cylinder head ing the sleeve nuts of the injection pipe, hold the
and the cylinder block. (M8: 5 bolts, 2 nuts) delivery valve holder with a wrench to prevent
corotation.
Note:
The water pump is installed to both the cylinder head CAUTION:
and the cylinder block. Always put a cap to prevent dust from getting in
the delivery valve holder and the nozzle holder.
21. Disconnect the leak-off pipe and remove the pack-

ing.
CAUTION:
Always put a cap to prevent dust from getting in
22. Remove the eyebolt and disconnect the fuel pipe.
CAUTION:
Always put a cap to prevent dust from getting in
1 2
2
3
1
6 4
WSLE0039
5
Name
1. Solenoid ASM
2. Housing Cover
3. Stud Bolt
WSLE0037
Name
1. Leak-off Pipe
2. Fuel Pipe
3. Eyebolt
4. Nozzle Holder
5. Injection Pump 1
6. Injection Pipe
23. Remove the solenoid ASM inserted in the back of

the injection pump installation part of the cylinder
block.
Note:
Take care when removing it since liquid gasket is used. 2
24. Remove the housing cover of the injection pump

installation part.
Since the liquid gasket is applied to the mating sur- WSLE0040
face of the cylinder body, insert a bolt to the hole Name
for M8 × 1.25 thread on the cover to remove the 1. Housing Cover
housing cover. 2. M8 × 1.25 for Replacer
Do not extract the two stud bolts since the sealant
is attached to them.
Note:
Take care when removing it since liquid gasket is used.
25. Remove the injection pump.
a. Align the hole of the fuel cut lever with the hole
of the governor cover, and then insert a pin (φ6
mm {0.236 in}) to the hole to hold the fuel cut
lever.
1 2
1
2
WSLE0042
Name
3
1. Control Link
2. Center Position of Injection Pump
3. Rack Pin of Injection Pump
WSLE0041
Name c. Remove the injection pump, and remove the

1. Fuel Cut Lever shim inserted in the pump installation part.
2. Pin (φ6 mm {0.236 in})
CAUTION:
3. Governor Cover
• Put the removed shim and the injection pump
b. Make sure that the pin groove of the control link together, attach a tag with cylinder number, and
is aligned with the center of the injection pump. check the thickness.
The removed shim cannot be reused.
CAUTION: • Do not extract the eight studs since the sealant
If the pin groove of the control link is not aligned is attached to them.
with the center of the injection pump, you may not
remove the injection pump because the rack pin of
the injection pump is stuck to the cylinder block.
4
3
WSLE0043
Name
1. Injection Pump ASM
2. Shim
3. Cylinder Block
4. Stud
26. Remove the control link. 29. Remove the water pipe from the rocker arm
Pull out the snap pin on the connecting part to the bracket.
link plate of the governor assembled in the timing
gear case.
Note:
Take care not to lose the snap pin.
2
1
3
WSLE0338
Name
1. Water Pipe
30. Remove the plug, and remove the oil cooler cover
from the oil cooler.
WSLE0212
31. Remove the center bolt, and remove the oil cooler
Name
ASM from the cylinder block.
1. Control Link
2. Link Plate (Governor)
3. Snap Pin
27. Disconnect the oil cooler water outlet hose and the
inlet hose.
28. Disconnect the water hose (between water pipe
and water pump).
1
2
3 3
4
WSLE0213
Name
1. Oil Cooler ASM
2
2. Center Bolt
3. Oil Cooler Cover
4. Plug
5. Packing
WSLE0337
32. Pull out the oil level gauge.
Name
1. Water Hose
2. Oil Cooler Water Outlet Hose
3. Oil Cooler Water Inlet Hose
Installation 4. Install the water pipe to the rocker arm bracket.
1. Insert the oil level gauge. Tightening torque:
2. Install the oil cooler ASM to the cylinder block. 18.6 — 28.4 N⋅m {1.9 — 2.9 kgf⋅m/13.7 — 20.9
lb⋅ft}
• Install the packing to the oil cooler ASM and the
center bolt.
Tightening torque:
Center bolt: 24.5 — 34.3 N⋅m {2.5 — 3.5 kgf⋅m/
18.1 — 25.3 lb⋅ft}
3. Install the oil cooler cover to the oil cooler.
• Install the O-ring to the oil cooler cover.
Tightening torque:
24.5 — 34.3 N⋅m {2.5 — 3.5 kgf⋅m/18.1 — 25.3
lb⋅ft}
WSLE0338
Name
1. Water Pipe
5
5. Install the water hose (between water pipe and

water pump).
6. Install the oil cooler water outlet hose and the inlet
1
2 hose with a white paint applied area in the oil
3 cooler side.
4
WSLE0213
Name
1. Oil Cooler ASM 1
2. Center Bolt
3. Oil Cooler Cover
4. Plug 4
5. Packing
WSLE0339
Name
1. Water Hose
2. Oil Cooler Water Outlet Hose
3. White Paint Applied Area
4. Oil Cooler Water Inlet Hose
7. Install the control link.
a. Insert the control link from the back to the con-
necting hole of the injection pump of the cylin-
der block, align it with the guide pin in the
connecting hole and assemble.
b. Assemble the pin part of the control link to the 2 4
link plate hole of the governor assembled in the
timing gear case, and fix it with the snap pin. 3
1
2
WSLE0151
Name
3 1. Control Link
2. Center Position of Injection Pump
3. Pin (φ6 mm {0.236 in})
4. Fuel Cut Lever
b. Align the shim with each stud and the knock

pin, check the thickness of the shim and install
WSLE0212
it. (Shim thickness; Refer to 1A-4, “Function
Name
Check, ISUZU Diesel Engine”)
1. Control Link
2. Link Plate (Governor) CAUTION:
3. Snap Pin Install a new shim whose thickness is the same as
one being removed when disassembling.
8. Install the injection pump.
a. Align the hole of the fuel cut lever with the hole
of the governor cover, insert a pin (φ6 mm
{0.236 in}) to the hole and get the lever upright.
(Control link is positioned on the center.)
CAUTION: 1
If the control link is not positioned on the center,
you may fold the link when installing the injection
pump. 2
WSLE0152
Name
1. Injection Pump ASM
2. Shim
3. Cylinder Block
c. Align the rack pin of the injection pump with the 9. Install the injection pump housing cover.
center position of the pump. Apply the liquid gasket (TB1207C) to the housing
d. Insert the injection pump along with the two cover and install it to the cylinder block on the
studs, align the knock hole with the knock pin of injection pump side.
the cylinder block, and assemble them. Tightening torque:
e. Make sure that the rack pin and the groove of 7.8 — 11.8 N⋅m {0.8 — 1.2 kgf⋅m/5.8 — 8.7 lb⋅ft}
the control link are aligned from the housing
cover installation part of the cylinder block side, Note:
and tighten the injection pump. • Remove the sealant attached to the housing cover
Tightening torque: installation part of the cylinder block with a packing
18.6 — 28.4 N⋅m {1.9 — 2.9 kgf⋅m/13.7 — 20.9 scraper completely and degrease sufficiently.
lb⋅ft} • Apply approx. 4 mm {0.157 in} width of liquid gasket
to the cover edge and approx. 2 mm {0.079 in} width
of liquid gasket to the circumference of the bolt in
the housing cover.
1
3
1
WSLE0153
Name
1. Control Link
2. Center Position of Injection Pump WSLE0154
3. Rack Pin Name
1. Housing Cover
f. Remove the pin (φ6 mm {0.236 in}) inserted into
the fuel cut lever, and make sure that the fuel
cut lever moves smoothly.
1 2
WSLE0155 WSLE0156
Name Name
1. Housing Cover 1. Solenoid ASM
2. Liquid Gasket Applied Area
3. Approx. 4 mm {0.157 in} width of the cover edge
4. Approx. 2 mm {0.079 in} of the circumference of
the bolt
10. Install the solenoid ASM.

1
a. Apply liquid gasket (TB1207C) to the installa-
tion surface (bit groove) of the solenoid for the 2
engine stopping.
Note:
• Remove the sealant attached to the installation part
of the solenoid and of the cylinder block with a pack- 3
ing scraper completely and degrease.
• Do not apply the liquid packing to the thread portion.
b. Insert the solenoid ASM from the back of the

cylinder block (back of the No.4 injection pump
rack) and tighten to the specified torque. WSLE0157
Tightening torque: Name

14.7 — 24.5 N⋅m {1.5 — 2.5 kgf⋅m/10.8 — 18.1 1. Solenoid ASM
lb⋅ft} 2. Installation Surface (Liquid Gasket Applied Area)
3. Thread Portion (Do not apply the liquid gasket.)
11. Install the fuel pipe to the injection pump and

Tightening torque:
19.6 — 24.5 N⋅m {2.0 — 2.5 kgf⋅m/14.5 — 18.1
lb⋅ft}
12. Install the leak-off pipe to the nozzle holder and
CAUTION:
Hold the pipe by your hand to prevent it from rotat-
ing when tightening.
Tightening torque:
9.8 — 13.7 N⋅m {1.0 — 1.4 kgf⋅m/7.2 — 10.1 lb⋅ft}
13. Connect the fuel pipe and the leak-off pipe with the
fuel hose and fix it with a clip.
2
2
1
WSLE0159
Name
WSLE0158 1. Injection Pipe
Name 2. Nozzle Holder
1. Leak-off Pipe 3. Injection Pump
2. Fuel Pipe
3. Nozzle Holder 15. Install the water pump ASM.
4. Injection Pump • Install the water pump ASM and the gasket to
5. Fuel Hose the cylinder block and the cylinder head, and
tighten it to the specified torque.
14. Install the injection pipe to the injection pump and
the nozzle holder, and tighten it with the sleeve Tightening torque:
nut. 18.6 — 28.4 N⋅m {1.9 — 2.9 kgf⋅m/13.7 — 20.9
lb⋅ft}
a. Screw the thread portion of the sleeve nut two
or three turns by your hand.
b. Hold the delivery valve holder of the injection
pump with a wrench and tighten the sleeve nut
securely.
Tightening torque:
14.7 — 24.5 N⋅m {1.5 — 2.5 kgf⋅m/10.8 — 18.1
lb⋅ft}
Important: 3
cannot move smoothly as the plunger and the
housing are compressed. Therefore, when tighten-
ing the sleeve nuts of the injection pipe, hold the
1
delivery valve holder with a wrench to prevent
corotation.
2
WSLE0160
Name
1. Tighten adjusting plate together.
2. Bolt: L = 40
3. Bolt: L = 60
16. Connect the water outlet pipe.
a. Assemble the thermostat, install the packing
and the water outlet pipe, and tighten it to the
specified torque.
Tightening torque:
18.6 — 28.4 N⋅m {1.9 — 2.9 kgf⋅m/13.7 — 20.9
lb⋅ft}
4 1
2
3
WSLE0331
Name
b. Install the gasket to the cylinder head cover.
Note:
Take care not to slide or distort the gasket when install-
WSLE0161
ing.
Name
c. Install the cylinder head cover to the rocker arm
1. Water Outlet Pipe
bracket and tighten it to the specified torque.
2. Packing
3. Water Pump Tightening torque:
4. Thermostat 7.8 — 11.8 N⋅m {0.8 — 1.2 kgf⋅m/5.8 — 8.7
lb⋅ft}
17. Install the exhaust manifold to the cylinder head.
19. Install the intake chamber to the cylinder head
• Insert the gasket and tighten to the specified cover.
torque.
• Insert the gasket and tighten to the specified
Tightening torque: torque.
18.6 — 28.4 N⋅m {1.9 — 2.9 kgf⋅m/13.7 — 20.9
Tightening torque:
lb⋅ft}
7.8 — 11.8 N⋅m {0.8 — 1.2 kgf⋅m/5.8 — 8.7
18. Install the cylinder head cover. lb⋅ft}
a. Apply the liquid gasket (TB1207B) to the posi- 20. Apply the liquid gasket (TB1207C) to the air inlet
tion in the cylinder head cover shown in the fig- pipe and install it.
ure, and install the baffle plate to the cylinder
head cover. Tightening torque:
7.8 — 11.8 N⋅m {0.8 — 1.2 kgf⋅m/5.8 — 8.7 lb⋅ft}
21. Install the PCV valve.
3
2
1
4
3
4
6
7
WSLE0336
WSLE0210 Name
Name 1. Turbocharger Oil Return Pipe
1. PCV Valve 2. Turbocharger Oil Feed Pipe
2. Inlet Chamber 3. Turbocharger
3. Cylinder Head Cover 4. Exhaust Adapter
4. Air Inlet Pipe
5. Gasket 26. Install the EGR cooler inlet pipe to the exhaust
6. Exhaust Manifold manifold.
7. Gasket • Insert the gasket and temporarily tighten the
bolts and nuts.
22. Install the turbocharger ASM to the exhaust mani-
fold.
torque.
Tightening torque:
21.6 — 31.4 N⋅m {2.2 — 3.2 kgf⋅m/15.9 — 23.2
lb⋅ft}
23. Install the exhaust adapter to the turbocharger.
torque.
Tightening torque:
21.6 — 31.4 N⋅m {2.2 — 3.2 kgf⋅m/15.9 — 23.2
lb⋅ft}
1
24. Install the turbocharger oil feed pipe.
Tightening torque:
Turbocharger side: 9.8 — 14.7 N⋅m {1.0 — 1.5 WSLE0335
kgf⋅m/7.2 — 10.8 lb⋅ft} Name
Cylinder block side: 22.0 — 27.0 N⋅m {2.2 — 2.8 1. EGR Cooler Inlet Pipe
kgf⋅m/16.2 — 19.9 lb⋅ft}
25. Install the turbocharger oil return pipe. 27. Install the EGR cooler bracket to the cylinder head
• Insert the gasket and tighten to the specified and temporarily tighten the bolts.
torque.
Tightening torque:
7.8 — 11.8 N⋅m {0.8 — 1.2 kgf⋅m/5.8 — 8.7
lb⋅ft}
28. Install the EGR cooler. 30. Install the EGR cooler outlet pipe.
• Insert the gasket and temporarily tighten the • Insert the gasket and temporarily tighten the
bolts. bolts and nuts.
2
WSLE0340 WSLE0342
Name Name
1. EGR Cooler 1. EGR Cooler Outlet Pipe
2. EGR Cooler Bracket
29. Install the orifice plate, the valve case and the
EGR cut solenoid to the intake chamber.
• Install the orifice plate and the gasket with pro-
truding section in the position shown in the fig-
ure.
• Install the connector of the EGR cut solenoid.
2
1
WSLE0341
Name
1. EGR Cut Solenoid
2. Valve Case
3. Protruding Section
4. Orifice Plate
31. Temporarily tighten the bolts and nuts to the speci- 32. Install the rear hanger.
fied torque according to the order given on the fig-
Tightening torque:
ure.
18.6 — 28.4 N⋅m {1.9 — 2.9 kgf⋅m/13.7 — 20.9
lb⋅ft}
5 3
WSLE0354
Name
1. Rear Hanger
33. Install the EGR cooler water inlet hose with a white
paint applied area in the cylinder block side.
34. Install the EGR cooler water outlet hose with a
6
white paint applied area in the water return pipe
WSLE0344
side.
Name
1-6. Show the order to tighten bolts and nuts.
2
Tightening torque:
1, 2, 3, 5: 21.6 — 31.4 N⋅m {2.2 — 3.2 kgf⋅m/15.9
— 23.2 lb⋅ft}
4, 6: 18.6 — 28.4 N⋅m {1.9 — 2.9 kgf⋅m/13.7 —
20.9 lb⋅ft}
3
WSLE0343
Name
1. EGR Cooler Water Inlet Hose
2. EGR Cooler Water Outlet Hose
3. White Paint Applied Area
35. Add coolant.

36. Add engine oil.
N m (kg m / lb ft)
18.6 - 28.4 (1.9 - 2.9 / 13.7 - 20.9)
18.6 - 28.4 (1.9 - 2.9 / 13.7 - 20.9)

9.8 - 13.7 (1.0 - 1.4 / 7.2 - 13.8)
21.6 - 31.4 (2.2 - 3.2 / 15.9 - 23.2)
14.7 - 24.5 (1.5 - 2.5 / 10.8 - 18.1)

21.6 - 31.4 (2.2 - 3.2 / 15.9 - 23.2)
14.7 - 24.5 (1.5 - 2.5 / 10.8 - 18.1)
18.6 - 28.4 (1.9 - 2.9 / 13.7 - 20.9)
7.8 - 11.8 (0.8 - 1.2 / 5.8 - 8.7)

24.5 - 34.3 (2.5 - 3.5 / 18.1 - 25.3)
7.8 - 11.8 (0.8 - 1.2 / 5.8 - 8.7)

7.8 - 11.8 (0.8 - 1.2 / 5.8 - 8.7)
18.6 - 28.4 (1.9 - 2.9 / 13.7 - 20.9)
21.6 - 31.4 (2.2 - 3.2 / 15.9 - 23.2)
18.6 - 28.4 (1.9 - 2.9 / 13.7 - 20.9)
21.6 - 31.4 (2.2 - 3.2 / 15.9 - 23.2)
9.8 - 14.7 (1.0 - 1.5 / 7.2 - 10.8)
22.0 - 27.0 (2.2 - 2.8 / 16.2 - 19.9)
7.8 - 11.8 (0.8 - 1.2 / 5.8 - 8.7) 21.6 - 31.4 (2.2 - 3.2 / 15.9 - 23.2)
WSLE0311
Rocker Arm Shaft

Components
2 3
WSLE0214
Name
1. Rocker Arm Shaft 5. Rocker Arm Shaft Plug
2. Lock Nut 6. Rocker Arm Bracket
3. Rocker Arm 7. Rocker Arm Shaft Pin
4. Adjusting Screw 8. Rocker Arm Spring
Removal Inspection
1. Remove the EGR cooler. Inspection of rocker arm and rocker arm shaft
Refer to 1A-20, “Removal, Engine Exterior Equip-
Check for wear, damage, clogging of oil port and other
ment”.
abnormality.
2. Remove the cylinder head cover.
ment”.
3. Remove the water pipe.
ment”.
4. Remove the rocker arm bracket ASM.
(M6 × 1.0: 5 bolts, 6 nuts)
Note:
Since liquid gasket is used on the mating surface to the
cylinder head, be careful not to damage the rocker arm
bracket when removing it.
* With screws for replacer (M8 × 1.25)
WSLE0232
2
Inspection for a bend of the rocker arm shaft
Hold the shaft on both ends with V block, and measure
3 the runout of the center by the dial gauge. (The bend
value should be a half of the runout.)
mm {in}
Standard value Service limit Repairing procedure
*
1 0.2 {0.008} or 0.3 {0.012} Replace.
less
*
WSLE0047
Name
1. Rocker Arm Bracket
2. Nut
3. Bolt
5. Pull out the eight push rods.
Disassembly
1. Remove plug of the rocker arm shaft.
2. Pull out the rocker arm shaft backward.
CAUTION:
When reinstalling the rocker arm, prepare tags writ-
ten down the cylinder numbers and symbols to dis-
tinguish “intake” and “exhaust”, to avoid installing
the improper position.
Inspection for wear of the rocker arm shaft
Measure the outside diameter of the shaft at sliding
portions (eight points) in the rocker arm.
mm {in}
Nominal dimension Service limit Repairing procedure
φ12 {0.472} φ11.85 {0.467} Replace.
WSLE0088
Inspection of rocker arm

Check the contact surface of the valve stem of the
rocker arm for stepped wear or damage.
If the stepped wear (1) and damage (2) of the contact
surface are slight, repair with the oil stone.
If the stepped wear and damage are extreme, replace
the rocker arm.
Inspection of clearance between the rocker

arm and the rocker arm shaft
2
Measure the bushing bore and calculate the clearance
between the arm and the outside diameter of the shaft.
3
Clearance between the arm and the mm {in}
shaft 1
4
0.005 — 0.045 Replace the rocker
0.2 {0.008}
{0.0002 — 0.0018} arm or the shaft.
WSLE0236
Name
1. Stepped Wear of the Contact Surface
2. Damage of the Contact Surface
3. Rocker Arm
4. Oil Stone
WSLE0235
Visual check of push rod Reassembly
Replace with new one if there is excessive wear or 1. Clean the rocker arm shaft and the oil port of the
damage. rocker arm by air.
2. Apply the engine oil to the rocker arm shaft and the
Inspection for a bend of the push rod rocker arm sliding portion.
Rotating the push rod on a surface plate, measure the 3. Install the rocker arm shaft and the rocker arm.
bend with the thickness gauge. When positioning the rocker arm shaft, align the
If the measured value exceeds the limit, replace with rocker shaft pin inserted to the rocker arm bracket
new one. with the cutout of the rocker arm shaft.
Push rod bend mm {in} Note:
Service limit 0.3 {0.012} or less When reinstalling the rocker arm, be sure to check the
tag and install to the original position.
1 2
1
WSLE0080
WSLE0251
Name Name
1. Push Rod 1. Pin
2. Thickness Gauge 2. Rocker Arm Shaft
4. Install the plug of the rocker arm.
Installation 3. Contact the rocker arm to the rocker spring, rotate
the crank, and set the No.1 cylinder to the exhaust
1. Put the push rod through the cylinder block and
top dead center.
insert it to the tappet.
4. Install the rocker arm bracket ASM along with the
2. Align it with a groove on the bottom of the rocker
stud bolt of the cylinder head, and tighten it to the
arm bracket and apply liquid gasket (TB1207B).
specified torque.
Note: Tightening torque:
Do not apply the liquid gasket to a groove around the 7.8 — 11.8 N⋅m {0.8 — 1.2 kgf⋅m/5.8 — 8.7 lb⋅ft}
oil gallery.
Note:
• Remove paint and sealant attached to the top of the
cylinder head and the bottom of the rocker arm
bracket with a PKG scraper etc., and degrease suffi-
ciently.
• Assemble it to the cylinder head within 5 minutes
1 after applying the sealant.
• When assembling, align the saucer part of the push
rod and the rocker arm adjusting screw.
2
WSLE0254 3
Name
2. Do not apply the liquid gasket to the groove.
(important)
1
3. Oil Gallery
Applied width of sealant
WSLE0145
Name
1. Rocker Arm Bracket
2. Nut
3. Bolt
1 5. Adjustment of valve clearance

Refer to 1A-4, “Function Check, ISUZU Diesel
Engine”.
2
6. Install the water pipe.
Refer to 1A-26, “Installation, Engine Exterior
Equipment”.
7. Install the cylinder head cover.
Equipment”.
WSLE0255
8. Install the EGR cooler.
Name
Equipment”.
1. Approx. 4 mm {0.157 in}
2. Approx. 2 mm {0.079 in}
N m (kg m / lb ft)
7.8 - 11.8 (0.8 - 1.2 / 5.8 - 8.7)
7.8 - 11.8 (0.8 - 1.2 / 5.8 - 8.7)
WSLE0302
Cylinder Head
Components
2
3
1
4
6
5
7
12
10
11
WSLE0050
Name
1. Connector 7. Spring Seat
2. Glow Plug 8. Valve Spring
3. Do not extract the five stud bolts since the seal- 9. Valve
ant is attached to them. 10. Hot Plug
4. Valve Seal 11. Valve Seat Insert
5. Valve Guide 12. Nozzle Holder
6. Split Collar
Removal 13. Gradually loosen the cylinder head bolts at an
equal balanced rate from outside toward the center
1. Remove the cooling fan.
as the order indicated in the diagram. (M12: 10
Refer to 1A-13, “Removal, Engine Accessories”.
bolts, M8: 5 bolts)
2. Remove the fan belt.
3. Remove the fan pulley.
4. Remove the generator.
Refer to 1A-13, “Removal, Engine Accessories”. 5 4 3 2 1
5. Remove the EGR cooler and the bracket.
Refer to 1A-13, “Removal, Engine Accessories”. 8 7
6. Remove the cylinder head cover. 12 15 11
ment”. 9 13 14 10 6
7. Remove the turbocharger.

ment”.
8. Remove the water pump.
ment”.
WSLE0049
9. Remove the injection pipe.
14. Remove the cylinder head ASM and the head gas-
ket.
ment”.
15. Pull out the tappet from the cylinder block.
10. Remove the leak-off pipe.
ment”.
11. Remove the rocker arm bracket.
Refer to 1A-37, “Removal, Rocker Arm Shaft”.
12. Remove the front hanger.
WSLE0048
Name
1. Cylinder Head ASM
2. Head Bolt (M12)
3. Head Gasket
4. Front Hanger
5. Head Bolt (M8)
Disassembly
1. Remove the exhaust manifold.
ment”.
2. Remove the connector, glow plug and nozzle
holder ASM before disassembling the valve sys-
tem.
3. Compress the valve spring to remove the split col-
lar, spring seat, valve spring and valve.
Special tool
Valve spring remover
5-8840-9030-0
CAUTION:
• Disassemble the cylinder head ASM on the flat
wood to prevent part damage.
• When removing the nozzle holder ASM, take
WSLE0330
great care not to damage the nozzle tip.
4. Remove the valve seal. Inspection

• Use pliers to remove the valve seal.
Inspection of cylinder head
Remove any carbon attached to the bottom of the
head, taking care not to damage the valve seat surface.
Check each part for damage and perform the color
check as required.
Water leakage: Water pressure test 490 kPa {71 psi}
(for three minutes)
WSLE0356
5. Remove the valve guide.

• Use a valve guide installer to pull out the valve
guides from the bottom of the cylinder head.
Special tool
Valve guide installer
5-8840-9035-0
WSLE0063
Inspection of bottom distortion
(Reference) Cylinder head height mm {in}
Place a straightedge on the four side-directions and the
two diagonal directions, and measure the distortion Engine model Standard value
with the thickness gauge. (Refer to the diagram.) 4LE2X 63.90 — 64.10 {2.516 — 2.524}
mm {in}
Standard Abnormal Repairing procedure
value value (need
repair)
Repair it with a surface
grinder. The total amount of
repaired values of the cylinder
0.075 block and of the cylinder head
{0.00295} 0.15 {0.006} should not exceed 0.3
or less {0.012}. If the measured value
exceeds the maximum
repaired value, replace the H
cylinder head.
WSLE0066
Distortion of exhaust manifold installation

surface
two diagonal directions, and measure the distortion
with the thickness gauge.
mm {in}
0.05 {0.002} or less 0.2 {0.008} Repair.
WSLE0064
WSLE0332
WSLE0230
Inspection of valve seat 2. Grind them after repair.
Contact width: A
Check the contact surface of the valve seat. If any
scratches and hollows exist or measured contact width
exceeds the limit, repair it.
Depression level: B
Install the valve to the cylinder head. Measure the
depression level of the seat with a depth gauge or with
a straightedge and a scale.
If the measured value exceeds the limit, replace the
valve seat insert.
mm {in}
Standard Service Repairing
value limit procedure
Contact width (A) 2.0 {0.079} 2.5 {0.098} Repair or
replace.
Depression IN 0.7 {0.028} 1.2 {0.047}
level (B) EX 0.9 {0.035} 1.5 {0.059}
Replacement of valve seat insert
If the depression level of the seat exceeds the limit,
replace the valve seat insert.
1. Arc-weld the entire inside diameter of the valve
seat insert.
1
2. Cool the valve seat insert for two to three minutes.
It contracts as it cools down, making it easier to
remove the valve seat insert.
3
3. Remove the valve seat insert, using a screwdriver.
Be sure not to hurt the cylinder head.
A
4 45
WSLE0067
Name
1. Cylinder Head
2. Valve Seat Insert
3. Valve
4. Cylinder Head Lower Surface
Repair of valve seat

1. Remove any carbon attached to the valve seat sur-
face. Use a seat cutter (15°, 45°, 75°) to cut off Name
scratches and hollows at minimum until they disap- 1. Arc-weld
pear, and adjust the contact width to the standard 2. Valve Seat Insert
value. 3. Screwdriver
4. Clean off carbon and metallic oxides on the insert

bore of the cylinder head.
5. Use a smooth pad and press-fit with a press. (9.8
— 14.7 kN {2,203 — 3,305 lb})
6. Apply compound to the valve seat surface, grind
them while rotating the valve, and make sure that it
contacts evenly over the circumference.
CAUTION:
After grinding, remove compound completely.
Inspection of valve guide

Note:
If there is a scratch or abnormal abrasion on the valve
stem and the inside diameter part of the valve guide,
replace the valve and valve guide together.
Name
1. Measure the valve guide clearance.
1. Pad
2. Valve Seat Insert • Measure the clearance between the valve
3. Press guide and valve stem within 10 mm {0.39 in}
from the valve guide, using a dial gauge.
• If the measured value exceeds the limit, replace
Inspection for wear of the valve stem the valve guide and valve altogether.
Measure the outside diameter at position as shown in
Clearance between the valve guide and mm {in}
the figure.
valve stem
Repair light stepped wear with the oil stone.
If the measured value is below the service limit, replace Standard Limit
the valve guide and the valve as a set. Inlet valve 0.023 — 0.056 0.2 {0.008}
{0.0009 — 0.0022}
mm {in}
Exhaust valve 0.030 — 0.063 0.25 {0.0098}
Nominal Service limit Repairing {0.0012 — 0.0025}
dimension procedure
Inlet φ7 {0.276} φ6.85 {0.270}
Replace.
Exhaust φ7 {0.276} φ6.80 {0.268}
Inspection of force (tension) of the valve
spring
Use a spring tester and read the scale when the spring
is compressed to the specified dimension.
N {lb}
Standard Service Repairing
value limit procedure
When compressed to
167 {38} 147 {33} Replace.
29.9 mm {1.177 in}
Inspection of thickness of the valve

If the measured value is below the service limit, replace
the valve guide and the valve as a set.
mm {in}
Nominal Service limit Repairing pro-
dimension cedure
IN 1 {0.039} 0.7 {0.028} Replace.
EX 0.8 {0.031} 0.5 {0.020}
Inspection of free height and squareness of

the valve spring
Free height (free length) ; A
Measure free length of the valve spring and if it is
shorter than the limit, replace the valve spring.
mm {in}
42.1 {1.657} 40 {1.575} Replace.
Squareness; B
Use a surface plate and a square to measure the valve
spring squareness.
If the measurement exceeds the limit, replace the valve
spring.
mm {in}
1.8 {0.071} or 2.5 {0.098} Replace.
less
Reassembly
1. Install the valve guide.
a. Hammer in the valve guide from the upper sur-
face of the cylinder head, using the valve guide
B
installer.
Special tool
5-8840-9035-0
WSLE0075
WSLE0357
Height from the upper surface of the cylinder

head to the edge surface of the valve guide: 9.5
mm {0.374 in}
Note:
When replacing the valve guide, it must be replaced
together with the valve.
2. Install the valve seal. 3. Install the valve.
a. When press-fitting, apply engine oil sufficiently Apply the mixture of the oil and Bellmoly Paste
over the outer circle of the valve guide. (molybdenum disulfide) to the valve stem part.
Engine oil : molybdenum = 1:1
b. Beat until the oil seal protruding section is
securely held to the valve guide groove. CAUTION:
Also, check that the spring does not come off. Be sure to prevent the valve from coming off and
Special tool causing dents after installing the valve.
Valve seal setting tool
5-8840-9033-0
CAUTION:
Take care to avoid damaging the lip of the seal.
WSLE0248
Name
1. Valve Stem
4. Install the valve spring and the spring seat.

WSLE0108
Install the valve spring with its narrow pitched side
(white paint side) facing downward.
3
1
WSLE0247
Name WSLE0110
1. Valve Guide
Name
2. Groove
1. White Paint
3. Protruding Section
5. Install the split collar.
Use the tool (remover) to compress the spring and
insert the split collar securely.
Special tool
5-8840-9030-0 1
1 2
3
WSLE0112
Name
1. Bolt
2. Eyebolt
3. Bracket
4. Nozzle ASM
WSLE0111 5. Gasket
Name
1. Split Collar 7. Install the exhaust manifold.
2. Remover Assemble the stamp mark (or seal) side of the gas-
ket facing the manifold.
6. Install the nozzle holder ASM.
Tightening torque:
a. Check the injection condition and injection 18.6 — 28.4 N⋅m {1.9 — 2.9 kgf⋅m/13.7 — 20.9
pressure of the injection nozzle, and perform lb⋅ft}
service before assembly. (Refer to 1A-4, “Func-
tion Check, ISUZU Diesel Engine”.)
b. Install the gasket to the cylinder head.
c. Install the nozzle holder ASM and tighten the
nozzle bracket to the specified torque.
2
Tightening torque:
31.4 — 41.2 N⋅m {3.2 — 4.2 kgf⋅m/23.2 — 30.4
lb⋅ft}
CAUTION:
• Be sure to prevent the nozzle holder tip from
adhering of dirt and from damaging.
• Use new gasket.
WSLE0249
Name
1. Exhaust Manifold
2. Gasket
8. Assemble the glow plug to the cylinder head and
Tightening torque:
20.0 — 25.0 N⋅m {2.0 — 2.5 kgf⋅m/14.8 — 18.4
lb⋅ft}
9. Install the connector to the glow plug and tighten to
the specified torque.
Tightening torque:
0.9 — 1.1 N⋅m {0.09 — 0.11 kgf⋅m/0.7 — 0.8 lb⋅ft}
1
1
WSLE0143
Name
1. Stamped Mark
3. Install the cylinder head ASM gently on the gasket.

4. Apply engine oil to the threads and the seating sur-
faces of the head bolts, and tighten them from the
center part to the outside bolts symmetrically in the
numerical order shown in the illustration.
Tightening torque:
WSLE0113 M12: 83.4 — 93.2 N⋅m {8.5 — 9.5 kgf⋅m/61.5 —
Name 68.7 lb⋅ft} → 60° — 90°
1. Glow Plug M8: 24.5 — 34.3 N⋅m {2.5 — 3.5 kgf⋅m/18.1 —
2. Connector 25.3 lb⋅ft}
Installation
1. Assemble the tappet to the cylinder block. (Check
the assemble position marked at the disassem-
bling.)
2. Install the head gasket.
Install the head gasket with the stamped mark fac-
ing upward.
WSLE0144
5. Install the rocker arm bracket.

Refer to 1A-40, “Installation, Rocker Arm Shaft”.
6. Install the front hanger and tighten to the specified 7. Install the leak-off pipe.
torque. Refer to 1A-26, “Installation, Engine Exterior
Equipment”.
Tightening torque:
18.6 — 28.4 N⋅m {1.9 — 2.9 kgf⋅m/13.7 — 20.9 8. Install the injection pipe.
lb⋅ft} Refer to 1A-26, “Installation, Engine Exterior
Equipment”.
9. Install the water pump.
Equipment”.
10. Install the turbocharger.
Equipment”.
Equipment”.
12. Install the EGR cooler and the bracket.
1
Equipment”.
13. Install the generator.
Refer to 1A-14, “Installation, Engine Accessories”.
14. Install the fan pulley.
WSLE0147 15. Install the fan belt.
Name Refer to 1A-14, “Installation, Engine Accessories”.
1. Front Hanger 16. Install the cooling fan.
N m (kg m / lb ft)
20.0 - 25.0 (2.0 - 2.5 / 14.8 - 18.4)
31.4 - 41.2 (3.2 - 4.2 / 23.2 - 30.4)

83.4 - 93.2 (8.5 - 9.5 / 61.5 - 68.7)
60 - 90
24.5 - 34.3 (2.5 - 3.5 / 18.1 - 25.3)
WSLE0303
Piston, Connecting Rod

Components
4
2
1 5
10
WSLE0053
Name
1. Piston Pin 6. Bearing
2. Piston 7. Cap Nut
3. Piston Ring 8. Cap
4. Snap Ring 9. Connecting Rod
5. Bushing 10. Connecting Rod Bolt
Removal
1
ment”. 2
2. Remove the rocker arm bracket. 3
Refer to 1A-37, “Removal, Rocker Arm Shaft”.
3. Remove the cylinder head ASM.
Refer to 1A-43, “Removal, Cylinder Head”.
4. Remove the mounting bolts and nuts of the oil pan,
and then remove the oil pan from the cylinder
block. (M6: 18 bolts, 4 nuts)
1 4
WSLE0216
Name
1. Oil Pump
2. Cylinder Block
3. Oil Pipe
4. Oil Strainer
7. Remove the piston and the connecting rod.

a. Rotate the crank and bring the removed piston
2 to the bottom dead center.
b. Loosen the cap nut of the connecting rod and
remove the cap.
WSLE0215
c. Further rotate the crank and bring the piston to
Name
the top dead center.
1. Oil Pan
2. Drain Plug d. Put a handle of a hammer or something on the
bottom of the connecting rod, and push the pis-
5. Remove the oil strainer mounting bolts from the ton ASM upward from the inside of the cylinder
bearing cap, and remove the oil strainer from the block.
oil pump.
CAUTION:
6. Loosen the sleeve nut and remove the oil pipe
• Remove any carbon attached to the inner wall of
(between the oil pump and the cylinder block).
the cylinder using a scraper before removing
the piston.
• Be careful not to damage the inner wall of the
cylinder when pushing out the piston ASM.
• Attach tags with each cylinder number to the
removed cap and the bearing and arrange them.
WSLE0054 WSLE0055
Name 2. Remove the piston pin.

1. Piston a. Use a commercial tool to remove the snap ring.
2. Connecting Rod Cap
b. Put a brass stick on the piston pin and gently
tap by a hammer to knock it out.
CAUTION:
Put the piston, piston ring, piston pin, connecting
rod, and so on in order according to the cylinder
number.
Disassembly
1. Use the piston ring setting tool (tool commercially
available is also acceptable) to remove the piston
ring.
WSLE0056
Special tool
Name
Piston ring setting tool
1. Piston Pin
1-8522-1029-0
2. Brass Stick
CAUTION:
Piston ring deforms if it is expanded beyond the
limit.
Inspection
Axial play of the connecting rod and the crank
pin
Measure an axial play before removing the connecting
rod.
1. Pull the connecting rod all the way to the front.
2. Insert a thickness gauge to the clearance between
the connecting rod cap and the crankshaft, and
then measure a play.
mm {in}
Standard value Service limit
0.20 — 0.33 {0.008 — 0.013} 0.35 {0.014}
Inspection of clearance with the cylinder bore

1. Measure the outside diameter of the piston at the WSLE0090
specified distance from top surface in the right-
angle direction to the piston pin. Inspection for wear of the piston pin (outside
Measurement position of outside diameter: 54.85 diameter)
mm {2.159 in} from the top surface.
Use a micrometer to measure the outside diameter of
the piston pin.
piston pin.
mm {in}
φ27 {1.063} φ26.970 Replace.
{1.0618}
WSLE0089
2. Calculate the clearance by the dimension of the

cylinder bore and the outside diameter dimension
of the piston.
mm {in}
Clearance with 0.040 — 0.085
major axis {0.0016 — 0.0033}
Outside diameter of the piston for service

WSLE0239
mm {in}
Inspection of clearance between the piston
Engine model Piston outside diameter Grade pins and piston pin holes
4LE2X φ84.945 — 84.960 NON Measure the inner diameter of the piston pin hole and
{3.3443 — 3.3449} calculate the clearance with the outside diameter of the
φ85.195 — 85.210 025 piston pin.
{3.3541 — 3.3547}
mm {in} mm {in}
Standard value Standard value Service Repairing
limit procedure
4LE2X 0.004 — 0.017 {0.00016 — 0.00070}
Top ring 0.085 — 0.105 0.2 Replace
{0.0033 — 0.0041} {0.008} the ring or
Inspection of piston ring end gap
the piston.
Second 0.050 — 0.085
Insert the ring to the cylinder bore and push it with the
ring {0.0020 — 0.0033} 0.15
piston head so that the ring makes a right angle with
the cylinder, then measure. Oil ring 0.030 — 0.070 {0.006}
{0.00120 — 0.00276}
mm {in}
Standard value Service limit Repairing
procedure
Top ring 0.20 — 0.35
{0.008 — 0.014}
1.5 {0.059}
Second 0.35 — 0.50
Replace.
ring {0.014 — 0.0.20}
Oil ring 0.20 — 0.40
1.0 {0.039}
{0.008 — 0.016}
WSLE0093
Inspection of distortion and parallelism of the

connecting rod
Use a connecting rod aligner to measure it.
mm {in}
Standard Service limit Repairing
value procedure
Distortion Repair or
0.05 {0.002}
(L = per 100 mm 0.2 {0.008} replace.
or less
{3.937 in})
Inspection of clearance between the piston
ring groove and the ring Distortion
0.05 {0.002}
(L = per 100 mm 0.15 {0.006}
1. Remove any carbon sludge from the piston ring or less
{3.937 in})
groove.
Using the old piston ring helps you to remove the
carbon easily.
2. Measure the clearance between the piston ring
and the ring groove using a thickness gauge at
several points.
If the measured value exceeds the limit, replace
the piston ring or the piston.
CAUTION:
When replacing the piston, replace the piston ring
also at the same time.
Replacement of bushing
Use the bench press to press-fit the bushing to the con-
necting rod.
Finished size of the bore after the bushing is mm {in}

press-fitted
Standard value
4LE2X φ27.00 {1.063}
(+0.008 — 0.015 {+0.00031 — 0.00060})
Inspection of clearance between the

connecting rod small end pin holes and the
piston pins
Measure the bushing bore and the piston pin outside
diameter and calculate the clearance.
mm {in}
Standard Service limit Repairing pro-
value cedure
WSLE0240
0.008 — 0.020 Replace the Name
4LE2X {0.00031 — 0.05 {0.002} bushing or the 1. Press
0.00080} piston pin.
Inspection of tension of the connecting rod

bearing
Check whether the tension of the bearing is sufficient.
mm {in}
Standard value Repairing procedure
W = 49.5 {1.949} or Use the one with extrusion and
more tension, and be careful about
D = φ49 {1.929} sticking of rear side.
L = 0.055 — 0.085
{0.00217 — 0.00330}
Standard for the bearing tension (reference) Inspection of outside diameter of the
crankshaft pin
1
Measure the outside diameter of the crankshaft pin,
and calculate the wear and the uneven wear.
If it exceeds the limit, replace the crankshaft.
1. Nominal dimension
mm {in}
3kN {674lbf}
Pin
2
4LE2X φ46 {1.811}
L
2. Uneven wear (the difference between the mea-
surements in X − X, Y − Y directions)
mm {in}
Service limit Repairing procedure
WSLE0241
Pin 0.05 {0.002} Replace the crankshaft.
Name
1. Tension (Free Condition) 3. Amount of wear
2. Extrusion
mm {in}
Clearance between the bearing and the crank
Pin 0.13 {0.005} Replace the crankshaft.
pin
1. Tighten the bearing cap to the specified torque.
Then measure the inside diameter.
Tightening torque:
23 — 26 N⋅m {2.3 — 2.7 kgf⋅m/17.0 — 19.2 lb⋅ft} →
100° — 115°
2. Measure the outside diameter of the after-men-
tioned crankshaft pin, and calculate the clearance.
Y
mm {in}
X X
Y
0.026 — 0.067 0.1 {0.0039} Replace the bearing.
{0.0010 — 0.0026}
WSLE0098
Cylinder and piston combination

The pistons are selected by the grade when assembled
at the factory. However, the grades are not set to the
standard pistons for service.
Cylinder bore Piston grade

grade At the ISUZU factory When servicing
A A NON-Grade
B B
C C
WSLE0097
Reassembly 2. Install the snap ring.
Insert the snap ring and fix it with the piston pin.
1. Assemble pistons and connecting rods.
Check to see the piston and connecting rod move
a. It is advisable to warm the piston at a tempera- smoothly.
ture of approx. 100°C {212°F} with a piston
heater. However, the piston is able to be
assembled when it is cold.
WSLE0117
3. Install the piston ring.

Use the piston ring setting tool to install the piston
WSLE0115
ring.
b. Apply engine oil sufficiently to the piston pin. Special tool
c. Assemble the connecting rod with the cylinder Piston ring setting tool
number stamped side facing the piston com- 1-8522-1029-0
bustion chamber direction, and push in the pis- a. Install the oil ring so that the end of the ring is in
ton pin. the opposite direction of 180° to that of the coil
At this time, check that the front mark on the expander.
piston head and the casting mark (ISUZU) on
the connecting rod are in the same direction. Note:
For the coil expander, make sure that there is no gap in
the joint.
1
2 b. Install the compression rings with T, 1T or 2T
mark facing upward in the order of the second
and top compression rings.
3
CAUTION:
The shapes of the top and second compression
rings are different.
WSLE0116
Name
1. Combustion Receiver Side
2. Front Mark
3. Engine Forward Direction
4. ISUZU Mark
5. Cylinder Number Stamped Side
Installation
1. Before inserting the piston ASM to the cylinder, set
the piston ring end as shown in the illustration,
avoiding the side-pressure direction (the right-
angle direction to the piston pin).
1
2
1
3
2
WSLE0118
3
Name
1. Top Ring
2. Second Ring
3. Oil Ring
WSLE0125
Name
1. Top Ring
2. Second Ring
3. Oil Ring
2. Bring the crankshaft to the top dead center posi-

tion.
1 3. Install the bearing to the connecting rod and the
bearing cap.
2 4. Apply engine oil to the inside of the bearing, the
piston ring, the ring groove and the side surface of
the piston, and the inside of the cylinder. Then
push the piston in the cylinder bore with the front
mark on it facing forward.
Also, check that the connecting rod alignment
number (cylinder number) is facing to the injection
pump side.
WSLE0252
Special tool
Name Piston ring compressor
1. T, 1T or 2T 5-8840-9018-0
2. Joint
6. Install the oil pipe (between the oil pump and the
cylinder block) and tighten the sleeve nut.
Tightening torque:
24.5 — 34.3 N⋅m {2.5 — 3.5 kgf⋅m/18.1 — 25.3
lb⋅ft}
7. Install the oil strainer to the oil pump and tighten
the strainer bracket to No.2 bearing cap.
Tightening torque:
18.6 — 28.4 N⋅m {1.9 — 2.9 kgf⋅m/13.7 — 20.9
lb⋅ft}
WSLE0253 3
5. Install the connecting rod cap.
a. Rotate the crank slowly to the bottom dead cen-
ter position. 2
At this time, push in the piston ASM as it follows
the crank.
b. Apply engine oil to the bearing and crank pin,
and install aligning the marking numbers of the 1
connecting rod and the bearing cap.
c. Apply engine oil to the threads and the seating
surface of the connecting rod.
WSLE0141
Tightening torque:
Name
23 — 26 N⋅m {2.3 — 2.7 kgf⋅m/17.0 — 19.2
1. Oil Pipe
lb⋅ft} → 100° — 115°
2. Oil Strainer
Note: 3. To No.2 Bearing Cap
Check that the crankshaft turns smoothly after assem-
bly of the connecting rod. 8. Install the oil pan.
a. Install the oil pan and the packing to the cylin-
der block and tighten the bolts evenly.
Tightening torque:
7.8 — 11.8 N⋅m {0.8 — 1.2 kgf⋅m/5.8 — 8.7
lb⋅ft}
b. Install the drain plug.
Tightening torque:
68.6 — 88.2 N⋅m {7.0 — 9.0 kgf⋅m/50.6 — 65.1
lb⋅ft}
WSLE0127
Name
1. Cylinder Number
9. Install the cylinder head ASM.
Refer to 1A-52, “Installation, Cylinder Head”.
1 Refer to 1A-40, “Installation, Rocker Arm Shaft”.
Equipment”.
WSLE0215
Name
1. Oil Pan
2. Drain Plug
N m (kg m / lb ft)
23 - 26 (2.3 - 2.7 / 17.0 - 19.2) 100 - 115
WSLE0304
Flywheel
Components
WSLE0313
Name
1. Flywheel
Removal Installation
1. Remove the flywheel. 1. Install the ring gear.
a. Block the crankshaft from rotating, and loosen Heat the ring gear evenly using a gas burner and
the mounting bolts in the order indicated in the strike with a hammer to install it.
diagram to remove the flywheel. After shrinkage fit, make sure that the ring gear is
stuck to the flywheel.
b. Put alignment marks before removing the fly-
wheel from the crankshaft. (Doing so makes CAUTION:
installing easy because the positions of the Do not heat the ring gear at a temperatures above
mounting bolts are fixed even if pitch of them is 200°C {392°F}.
not equal.)
c. Gently tap the flywheel by a plastic hammer or
similar tool to remove it.
CAUTION:
Be careful not to damage the ring gear.
3 1
5 6
2 4
2. Install the flywheel.

Apply engine oil to the threads and the seating sur-
face of the mounting bolts, and then install the fly-
wheel to the crankshaft.
Tighten the mounting bolts in a balanced way in
WSLE0218
the numerical order shown in the illustration.
2. Take out the ring gear.
Put a brass stick on the ring gear and strike with a Tightening torque:
hammer to remove it. 88.3 — 108 N⋅m {9.0 — 11.0 kgf⋅m/65.1 — 79.7
lb⋅ft}
Note:
Install the flywheel checking the installation position
since the bolt hole pitch is not equal.
WSLE0103
3 1
5 6
2 4
WSLE0139
Name
1. Engine Oil Application
N m (kg m / lb ft)
88.3 - 108 (9.0 - 11.0 / 65.1 - 79.7)
WSLE0314
Crankshaft Front Oil Seal

Components
WSLE0315
Name
1. Crankshaft Pulley 3. Timing Gear Case
2. Front Oil Seal 4. Governor Cover
Removal
1. Remove the cooling fan and the fan belt.
2. Remove the fan pulley. 4
Refer to 1A-13, “Removal, Engine Accessories”. 3
Refer to 1A-13, “Removal, Engine Accessories”. 2
5. Remove the injection pipe. 1
ment”.
6. Remove the fuel pipe.
ment”.
7. Remove the solenoid ASM.
Refer to 1A-20, “Removal, Engine Exterior Equip- WSLE0217
ment”. Name
8. Remove the injection pump housing cover. 1. Mounting Bolt
Refer to 1A-20, “Removal, Engine Exterior Equip- 2. Washer
ment”. 3. Crank Pulley
4. Crankshaft
9. Remove the injection pump.
Refer to 1A-20, “Removal, Engine Exterior Equip- 13. Remove the timing gear case.
ment”.
a. Before removing the timing gear case, make
10. Remove the control link. sure that control link supported by the cylinder
Refer to 1A-20, “Removal, Engine Exterior Equip- block and the link plate of the governor are sep-
ment”. arated.
11. Remove the oil pan. If they are connected, remove the snap pin and
Refer to 1A-55, “Removal, Piston, Connecting separate them.
Rod”.
12. Remove the crank pulley.
a. Block the crankshaft from rotating, and loosen
the mounting bolts of the pulley to remove it. 1
b. Remove the washer and the pulley.
CAUTION:
Do not reuse the bolt and washer.
2
WSLE0212
Name
1. Control Link
2. Link Plate (Governor)
3. Snap Pin
b. The timing gear case should be removed with Inspection
the governor and the front oil seal.
Inspection of oil seal
Note: If fault is found in the lip section of the oil seal, replace it
Since liquid gasket is applied to the mating surface to with the new one.
the cylinder block, take great care not to remove them
forcedly to damage or deform them.
WSLE0102
Name
1. Timing Gear Case
WSLE0221
2. Front Oil Seal
14. Remove the front oil seal from the timing gear
case.
• Remove the oil seal with a screwdriver avoiding
Installation
damage to the oil seal contact surface on the
timing gear case. 1. Install the front oil seal.
a. Apply enough engine oil to the felt section of
the oil seal.
b. Install the front oil seal to the timing gear case
with a front oil seal installer.
Install it at the position due to the L dimension
shown in the illustration.
Special tool
Front oil seal installer
5-8840-9031-0
mm {in}
L dimension 60.5±0.1 {2.382±0.0039}
1
2 2
L
WSLE0136 WSLE0137
Name Name
1. Front Oil Seal 1. Governor Cover
2. Timing Gear Case 2. Timing Gear Case
3. Front Oil Seal
2. Install the timing gear case (with governor) to the
cylinder block. 3. Install the crank pulley.
a. Let the link plate of the governor which is a. Install the crank pulley to the crankshaft.
assembled in the gear case through the con- b. Block the crankshaft from rotating, assemble
nection hole of the injection pump. the washer, and tighten it with the mounting
b. Apply engine oil to the both ends of the bushing bolts.
section of the governor main spring lever.
c. Apply the liquid gasket (TB1207B) to the gear CAUTION:
case and install to the cylinder block. Replace the bolt and washer with new ones.
Tightening torque: Tightening torque:

18.6 — 28.4 N⋅m {1.9 — 2.9 kgf⋅m/13.7 — 20.9 167 — 186 N⋅m {17.0 — 19.0 kgf⋅m/123.2 —
lb⋅ft} 137.2 lb⋅ft}
d. Assemble the packing and the governor cover

to the top of the gear case and tighten them to
the specified torque.
Tightening torque:
7.8 — 11.8 N⋅m {0.8 — 1.2 kgf⋅m/5.8 — 8.7
lb⋅ft}
4
Note:
Apply enough engine oil to the main and dust lip sec-
tion of the front oil seal before installing. 2
3
1
WSLE0140
Name
1. Washer
2. Crank Pulley
3. Front Oil Seal
4. Crankshaft
4. Install the oil pan. 9. Install the fuel pipe.
Refer to 1A-62, “Installation, Piston, Connecting Refer to 1A-26, “Installation, Engine Exterior
Rod”. Equipment”.
5. Install the control link. 10. Install the injection pipe.
Refer to 1A-26, “Installation, Engine Exterior Refer to 1A-26, “Installation, Engine Exterior
Equipment”. Equipment”.
6. Install the injection pump. 11. Install the generator bracket.
Refer to 1A-26, “Installation, Engine Exterior Refer to 1A-14, “Installation, Engine Accessories”.
Equipment”. 12. Install the generator.
7. Install the injection pump housing cover. Refer to 1A-14, “Installation, Engine Accessories”.
Refer to 1A-26, “Installation, Engine Exterior 13. Install the fan pulley.
Equipment”. Refer to 1A-14, “Installation, Engine Accessories”.
8. Install the solenoid ASM. 14. Install the cooling fan and the fan belt.
Equipment”.
N m (kg m / lb ft)
7.8 - 11.8 (0.8 - 1.2 / 5.8 - 8.7)
7.8 - 11.8 (0.8 - 1.2 / 5.8 - 8.7)
18.6 - 28.4 (1.9 - 2.9 / 13.7 - 20.9)
167 - 186 (17.0 - 19.0 / 123.2 - 137.2)
WSLE0305
Crankshaft Rear Oil Seal

Components
3
1 2
WSLE0316
Name
1. Flywheel Housing 3. Retainer
2. Rear Oil Seal
Removal 5. Remove the rear oil seal from the retainer.
1. Remove the starter. • Remove the oil seal with a screwdriver avoiding
Refer to 1A-13, “Removal, Engine Accessories”. damage to the oil seal contact surface on the
retainer.
2. Remove the flywheel.
Refer to 1A-66, “Removal, Flywheel”.
3. Remove the flywheel housing. Installation
a. Remove the mounting bolt to the cylinder block. 1. Install the rear oil seal to the retainer with a rear oil
b. Gently tap the housing by a plastic hammer or seal installer.
similar tool to remove it from the cylinder block. Special tool
Rear oil seal installer
5-8840-9032-0
4
3
2
WSLE0138
4. Remove the retainer.

Remove the retainer with the rear oil seal from the WSLE0329
back of the cylinder block. Name

1. Retainer
CAUTION: 2. Rear Oil Seal
Since liquid gasket is applied, be careful not to 3. 1.75 mm {0.069 in}
remove it forcedly to damage or deform it. 4. 1.25 mm {0.049 in}
2. Install the retainer.

Apply a thin coat of engine oil to the lip section of
the oil seal and install the retainer. (Apply the liquid
gasket TB1207B)
CAUTION:
Be sure to prevent the big end of the crankshaft
1
from adhering of dust or foreign materials.
2
The tightening order of the retainer is as shown in
the illustration and you should tighten it to the fol-
lowing torque.
Tightening torque:
7.8 — 11.8 N⋅m {0.8 — 1.2 kgf⋅m/5.8 — 8.7 lb⋅ft}
WSLE0226
Name
1. Retainer
2. Rear Oil Seal
3. Install the flywheel housing to the cylinder block.
Tightening torque:
41.2 — 54.9 N⋅m {4.2 — 5.6 kgf⋅m/30.4 — 40.5
lb⋅ft}
6 4
8 7
1 2
3 5
WSLE0128
WSLE0138

Refer to 1A-66, “Installation, Flywheel”.
5. Install the starter.
N m (kg m / lb ft)
7.8 - 11.8 (0.8 - 1.2 / 5.8 - 8.7)
41.2 - 54.9 (4.2 - 5.6 / 30.4 - 40.5)
WSLE0306
Timing Gear Train

Components
WSLE0317
Name
1. Thrust Collar 3. Idle Gear Shaft
2. Idle Gear 4. Crankshaft Gear
Removal
1. Remove the cooling fan and the fan belt.
2. Remove the fan pulley.
5. Remove the injection pipe.
ment”.
6. Remove the fuel pipe.
ment”.
7. Remove the solenoid ASM.
Refer to 1A-20, “Removal, Engine Exterior Equip- WSLE0224
ment”.
8. Remove the injection pump housing cover.
Inspection of axial play of the idle gear
Refer to 1A-20, “Removal, Engine Exterior Equip- Measure an axial play of the gear before removing the
ment”. idle gear.
9. Remove the injection pump. 1. Insert a thickness gauge between the idle gear and
Refer to 1A-20, “Removal, Engine Exterior Equip- the thrust collar to measure a clearance.
ment”. 2. If the measurement exceeds the limit, replace
10. Remove the control link. either the thrust collar or the idle gear.
ment”. Axial play of idle gear mm {in}
11. Remove the oil pan. Standard value Service limit

Refer to 1A-55, “Removal, Piston, Connecting 0.058 — 0.115 {0.0023 — 0.2 {0.008}
Rod”. 0.0045}
12. Remove the crank pulley.
Refer to 1A-69, “Removal, Crankshaft Front Oil
Seal”.
13. Remove the timing gear case.
Seal”.
14. Remove the idle gear and the idle gear shaft.
Inspection
Inspection of backlash of the timing gear
Before removing the timing gear, measure backlash of
it.
1. Put a dial gauge on the tooth of the measured
1
gear.
2. Move the gear right and left lightly, and read the
deflection of the dial gauge.
If it exceeds the limit, replace the timing gear.
WSLE0225
Backlash of the timing gear mm {in} Name

1. Thickness Gauge
Location Standard Service limit
value
Crank gear/Idle gear 0.04 {0.0016} 0.2 {0.008}
Idle gear/Camshaft gear 0.03 {0.0012} 0.2 {0.008}
Inspection of idle gear and gear shaft
1. If there is excessive wear or damage on the sliding
surface of the idle gear and the gear shaft, and on
the inside of the idle gear bushing, replace either
the shaft or the gear.
2. If there is stepped wear or something on the idle
gear and the thrust collar, replace either the idle
gear or the thrust collar.
WSLE0105
Inspection of clearance between the idle gear

1
bushing and the shaft
Measure the idle gear bushing bore and calculate the
clearance between the bushing and the outside diame-
ter of the idle gear shaft.
mm {in}
WSLE0246
Name Standard value Service limit Repairing procedure

1. Idle Gear Shaft 0.025 — 0.085 Replace the idle gear
0.2 {0.008}
{0.00098 — 0.00330} or the shaft.
Inspection of uneven wear of the idle gear

shaft
Measure the outside diameter of the idle gear shaft
using a micrometer, and calculate the amount of
uneven wear.
mm {in}
φ45 {1.772} 0.1 {0.0039} Replace.
Installation c. Apply engine oil to the thrust collar sliding sur-
face and the threads and the seating surfaces
1. Install the idle gear.
of the bolts. Then install to the idle gear with the
a. Install the idle gear shaft to the cylinder block. chamfered side of the collar facing the outside,
(The position where the oil hole is located and tighten it with the bolts.
obliquely upward)
Tightening torque:
b. Apply engine oil to the bushing surface and the
20.6 — 30.4 N⋅m {2.1 — 3.1 kgf⋅m/15.2 — 22.4
tooth surface of the idle gear, and the idle gear
lb⋅ft}
shaft. Then assemble the idle gear with its tim-
ing points (black dots) facing the forward direc- CAUTION:
tion and aligning the timing points (black dots) Assemble the idle gear shaft aligning the position-
of the camshaft gear and the crank gear at the ing pin with the knock hole.
same time.
1 3
2
2
5
4 3
WSLE0132 WSLE0131
Name Name
1. Camshaft Gear 1. Thrust Collar
2. Timing Point 2. Timing Point
3. Crank Gear 3. Idle Gear
4. Idle Gear 4. Idle Gear Shaft
5. Timing Point
2. Install the timing gear case.

Refer to 1A-70, “Installation, Crankshaft Front Oil
Seal”.
3. Install the crank pulley.
Seal”.
4. Install the oil pan.
Refer to 1A-62, “Installation, Piston, Connecting
Rod”.
5. Install the control link.
Equipment”.
6. Install the injection pump.
Equipment”.
7. Install the injection pump housing cover.
Equipment”.
8. Install the solenoid ASM. 11. Install the generator bracket.
Equipment”. 12. Install the generator.
9. Install the fuel pipe. Refer to 1A-14, “Installation, Engine Accessories”.
Refer to 1A-26, “Installation, Engine Exterior 13. Install the fan pulley.
Equipment”. Refer to 1A-14, “Installation, Engine Accessories”.
10. Install the injection pipe. 14. Install the cooling fan and the fan belt.
Equipment”.
N m (kg m / lb ft)
20.6 - 30.4 (2.1 - 3.1 / 15.2 - 22.4)
WSLE0307
Camshaft
Components
10
5
4
WSLE0318
Name
1. Sleeve 6. Bearing
2. Lock Nut 7. Pin
3. Flyweight ASM 8. Camshaft
4. Camshaft Gear 9. Wear Ring
5. Snap Ring 10. Bearing
Removal Inspection
1. Remove the EGR cooler and the bracket. Inspection of camshaft
Check the journal portion and the cam portion for wear,
ment”.
damage, and other abnormality.
Refer to 1A-20, “Removal, Engine Exterior Equip- CAUTION:
ment”. The ball bearings are fitted to the front and rear
3. Remove the rocker arm bracket. parts of the camshaft. Also, the roller bearing is
Refer to 1A-37, “Removal, Rocker Arm Shaft”. press-fitted to the cylinder block at the center part.
Check that each bearing has no rattle and rotates
4. Remove the cylinder head.
smoothly with this condition.
5. Remove the tappet.
6. Remove the timing gear case.
Seal”.
7. Remove the camshaft gear. 1
a. Pull out the sleeve from the end of the cam-
shaft.
b. Remove the lock nut from the camshaft gear,
and remove the flyweight ASM and the cam-
shaft gear.
8. Remove the camshaft.
a. Remove the snap ring which holds the front
bearing of the camshaft from the ring groove of
the cylinder block.
b. Pull out the camshaft with the bearing from the
cylinder block. WSLE0081
Name
1. Camshaft
Inspection of journal and cam

1. Height of the cam (A − B)
1
mm {in}
Standard Service limit Repairing
2 value procedure
Inlet 6.13 {0.241} 5.83 {0.230}
Replace.
Exhaust 6.43 {0.253} 6.13 {0.241}
2. Center journal diameter (the dimensions in X − X

and Y − Y directions)
mm {in}
WSLE0052
Name Nominal dimension Service limit Repairing procedure

1. Camshaft φ52 {2.047} φ51.92 {2.044} Replace.
2. Snap Ring
3. Uneven wear of the journal (the difference
between the measurements in X − X and Y − Y mm {in}
directions) Standard value Service limit Repairing procedure
mm {in} 0.02 {0.0008} or 0.1 {0.0039} Replace.

less
φ52 {2.047} 0.05 {0.002} Replace.
WSLE0084
WSLE0082 Inspection of tappet

Check the contact surface with the camshaft.
If there is pitching, defective contact, vermiculation, or
crack, replace the tappet.
I II 3 2 1
I II
Y
A X X
B Y
4
WSLE0083
Inspection of camshaft runout

1. Put the camshaft on the V block. WSLE0237
2. Place the dial gauge to the center journal part. Name

1. Normal
3. Rotate the camshaft once and read the deflection
2. Cracks
of the indicator.
3. Pitching
4. Abnormal Contact
the camshaft.
Inspection for wear of the tappet outside
diameter
Use a micrometer to measure the outside diameter of
the tappet.
tappet.
Outside diameter of the tappet mm {in}

φ20.97 — 20.98 {0.8256 — 20.92 {0.8240}
0.8260}
WSLE0238
WSLE0091
Inspection of clearance between the tappet

and the cylinder block
Use the bore gauge to measure the bore diameter of
the tappet insertion hole on the cylinder block and cal-
culate the clearance.
Clearance between the tappet and the cylinder mm {in}

block hole
0.020 — 0.054 {0.0008 — 0.1 {0.0039}
0.0021}
Installation
1. Install the camshaft ASM.
a. Apply engine oil to the camshaft journal, bear-
ing, cam surface, and the inside of the cylinder 5
4
block bearing. Then assemble the camshaft
ASM. 3
CAUTION: 2
Be careful not to damage the bearing when assem- 1
bling.
b. Install the snap ring to the outside of the front

bearing, and check that the camshaft rotates
smoothly.
WSLE0130
Name
1. Sleeve
2. Lock Nut
3. Flyweight
4. Timing Point
5. Camshaft Gear
3. Install the timing gear case.

Seal”.
4. Install the tappet.
5. Install the cylinder head.
WSLE0129 Refer to 1A-52, “Installation, Cylinder Head”.
2. Install the camshaft gear and the sleeve. 6. Install the rocker arm bracket.
a. Install the camshaft gear to the camshaft with Refer to 1A-40, “Installation, Rocker Arm Shaft”.
its timing point (black dot) facing the forward 7. Install the cylinder head cover.
direction. Refer to 1A-26, “Installation, Engine Exterior
b. Assemble the flyweight, apply engine oil to the Equipment”.
thread and the seating surface of the lock nut,
and tighten.
Tightening torque:
165 — 185 N⋅m {16.8 — 18.8 kgf⋅m/121.7 —
136.4 lb⋅ft}
c. Apply engine oil to the sleeve shaft and the slid-
ing surface of the flyweight.
d. Insert the sleeve collar section to the concave
portion of the flyweight. Then insert the sleeve
shaft to the end of the camshaft.
Note:
Check that the sleeve moves smoothly.
N m (kg m / lb ft)
165 - 185 (16.8 - 18.8 / 121.7 - 136.4)
WSLE0308
Crankshaft
Components
WSLE0319
Name
1. Crankshaft Gear 3. Crankshaft
2. Bearing Cap
Removal 12. Remove the crankshaft.
1. Remove the engine accessories. a. Gradually loosen the bolts of each bearing cap
Refer to 1A-13, “Removal, Engine Accessories”. evenly in the order shown in the illustration.
Tap the cap lightly with a copper hammer to
2. Remove the engine exterior equipment.
remove it with the bearing.
ment”. b. Remove the crankshaft ASM.
3. Remove the rocker arm bracket. c. Remove the thrust bearing from No.2 journal of
Refer to 1A-37, “Removal, Rocker Arm Shaft”. the cylinder block.
4. Remove the cylinder head. CAUTION:
Refer to 1A-43, “Removal, Cylinder Head”. Attach tags with each cylinder number to the
5. Remove the piston and the connecting rod. removed cylinder parts to identify installation posi-
Refer to 1A-55, “Removal, Piston, Connecting tions, and put them in order.
Rod”.
7. Remove the crankshaft front oil seal.
Seal”.
1
8. Remove the crankshaft rear oil seal.
Refer to 1A-74, “Removal, Crankshaft Rear Oil
Seal”. 1 5 4
9 8
9. Remove the idle gear.
2
Refer to 1A-77, “Removal, Timing Gear Train”.
6 7
10. Remove the camshaft. 2 10 3
Refer to 1A-82, “Removal, Camshaft”.
11. Remove the oil pump ASM from the cylinder block.
WSLE0229
Name
1
1. Arrow Mark
2. Front
Disassembly
1. Remove the gear from the crankshaft.
WSLE0223
Name
1. Cylinder Block
Inspection
mm {in}
Inspection of axial play of the crankshaft
Measure an axial play before removing the crankshaft.
Journal 0.05 {0.002} Replace the crankshaft.
1. Pull the crankshaft all the way to the front.
2. Insert the thickness gauge to the front side of No.2
3. Amount of wear
journal portion of the crankshaft (thrust bearing
installation part) and measure the play. mm {in}
the thrust bearing. Service limit Repairing procedure
Journal 0.14 {0.0055} Replace the crankshaft.
Axial play of crankshaft mm {in}
0.058 — 0.208 {0.0023 — 0.3 {0.012}
0.0082}
X X
1
Y
WSLE0098
Inspection of outside diameter of the

crankshaft pin
WSLE0228 Measure the outside diameter of the crankshaft pin,
Name and calculate the wear and the uneven wear.
1. Measurement of Play If it exceeds the limit, replace the crankshaft.
2. Front 1. Nominal dimension
mm {in}
Inspection of crankshaft
Pin
Check for wear, damage, clogging of oil port and other
4LE2X φ46 {1.811}
abnormality.
Inspection of outside diameter of the 2. Uneven wear (the difference between the mea-
crankshaft journal surements in X − X, Y − Y directions)
Measure the outside diameter of the crankshaft journal, mm {in}

and calculate the amount of wear and uneven wear.
If it exceeds the limit, replace the crankshaft.
1. Nominal dimension Pin 0.05 {0.002} Replace the crankshaft.
mm {in} 3. Amount of wear

Journal
mm {in}
4LE2X φ60 {2.362}
2. Uneven wear (the difference between the mea- Pin 0.13 {0.005} Replace the crankshaft.
surements in X − X, Y − Y directions)
Inspection of tension of the journal main
bearing
Check whether the tension of the bearing is sufficient.
mm {in}
Y W = 64.5 — 65.5
{2.539 — 2.579}
X X 4LE2X D = φ64 {2.520} W = 64.1 {2.524}
L = 0.02 — 0.06
Y {0.0008 — 0.00236}
Repairing procedure: use the one with extrusion and

tension, and be careful about sticking of the rear side.
Standard for the bearing tension (reference)
1
WSLE0098
Inspection of clearance between the journal

and the bearing
Tighten the bearing cap to the specified torque and
measure the inside diameter of the bearing to calculate
4.9kN {1101.6lbf}
the clearance.
2
Tightening torque:
83.4 — 93.2 N⋅m {8.5 — 9.5 kgf⋅m/61.5 — 68.7 lb⋅ft} L
Clearance between the journal and mm {in}

the bearing
0.029 — 0.072 0.11 {0.0043} Replace the bearing.
{0.0011 — 0.0028}
WSLE0242
Name
1. Tension (Free Condition)
2. Extrusion
Inspection of crankshaft runout

Hold the journal portions on both ends of the crankshaft
with V block, and measure the runout of the center jour-
nal using the dial gauge.
mm {in}
0.025 {0.00098} 0.05 {0.002} Replace.
or less
WSLE0099
Reassembly
1. Install the crankshaft gear.
Put a brass stick on the gear and strike with a
hammer to install.
WSLE0100
Inspection of crankshaft gear

Check visually for damage and other abnormality.
Replace if there is damage or serious pitching. WSLE0245
Installation
1. Install the crankshaft upper bearing.
a. While there are the oil holes and oil grooves on
the upper bearing (block side), there is none on
the lower bearing (bearing cap side). Take care
when assembling.
CAUTION:
If assembling the lower bearing and upper bearing
inversely, seizure occurs in the crankshaft bearing.
Be careful with it.
1
WSLE0101
WSLE0122
Name
1. Upper Bearing
2. Lower Bearing
b. Wipe the rear side of the crankshaft bearing 4. Install the crankshaft bearing cap.
and the inside of the crank bearing housing of a. Install the bearings to each bearing cap and
the cylinder block, and check that there is no apply engine oil sufficiently. Then assemble
foreign matter. them from the front so that the arrow marks on
c. Assemble the pawl of the bearing to the cutout the caps facing toward the front of the engine in
portion of the cylinder block securely, and apply the order of the marking numbers.
engine oil sufficiently to the inside of the bear- b. Apply engine oil to the threads and the seating
ing (sliding surface). surface of the bearing cap bolt. Then tighten
2. Install the crankshaft. evenly in several batches in the order shown in
Put the crankshaft on the cylinder block carefully. the illustration, and at the end, tighten to the
3. Install the crankshaft lower bearing. specified torque.
Assemble the thrust bearing with the oil groove Tightening torque:
facing outward. (No.2 journal portion) 83.4 — 93.2 N⋅m {8.5 — 9.5 kgf⋅m/61.5 — 68.7
lb⋅ft}
CAUTION:
• Be sure to prevent the installation position and c. After assembling, check that the crankshaft
sliding surface of the bearing from adhering of rotates.
dirt.
• Be sure to prevent the backside of the bearing
(installation position) from adhering of oil.
1
10 6 7
2 3
5 4 3 2 1
1
5 1 4
9 8
WSLE0124
3
Name
1. Arrow Mark
2. Engine Oil Application
WSLE0123
5. Install the oil pump ASM.
Name
1. Thrust Bearing a. Pour engine oil to the oil pipe and installation
2. Crankshaft port of the oil strainer.
3. Upper Bearing Pawl b. Install the oil pump ASM to the cylinder block.
4. Lower Bearing Pawl Tightening torque:
18.6 — 28.4 N⋅m {1.9 — 2.9 kgf⋅m/13.7 — 20.9
lb⋅ft}
6. Install the camshaft.
Refer to 1A-85, “Installation, Camshaft”.
Refer to 1A-79, “Installation, Timing Gear Train”.
8. Install the crankshaft rear oil seal.
1
Refer to 1A-74, “Installation, Crankshaft Rear Oil
Seal”.
9. Install the crankshaft front oil seal.
Seal”.
11. Install the pistons and connecting rods.
Refer to 1A-62, “Installation, Piston, Connecting
Rod”.
WSLE0133
Name 13. Install the rocker arm bracket.
1. Cylinder Block Refer to 1A-40, “Installation, Rocker Arm Shaft”.
14. Install the engine exterior equipment.
Equipment”.
15. Install the engine accessories.
N m (kg m / lb ft)
83.4 - 93.2 (8.5 - 9.5 / 61.5 - 68.7)
WSLE0309
Cylinder Block
Components
WSLE0310
Name
1. Cylinder Block
Removal Inspection
1. Remove the engine accessories. Inspection of cylinder block
Check the cylinder block for wear, damage, water leak-
2. Remove the engine exterior equipment. age and other abnormality.
1. Use a wooden plug or something to block the
ment”.
water passage and check for leakage.
3. Remove the rocker arm bracket. Water leakage: Water pressure test 490 kPa {71
Refer to 1A-37, “Removal, Rocker Arm Shaft”. psi} (for three minutes)
4. Remove the cylinder head. 2. Check for damage by the color check.
3. Check the jet hole of the piston cooling and water
5. Remove the piston and the connecting rod. hole between bores for clogging or something
Refer to 1A-55, “Removal, Piston, Connecting abnormal.
Rod”.
7. Remove the crankshaft front oil seal.
Seal”.
8. Remove the crankshaft rear oil seal.
Refer to 1A-74, “Removal, Crankshaft Rear Oil
Seal”.
9. Remove the idle gear.
Refer to 1A-77, “Removal, Timing Gear Train”.
10. Remove the camshaft.
Refer to 1A-82, “Removal, Camshaft”.
11. Remove the crankshaft.
Refer to 1A-88, “Removal, Crankshaft”.
WSLE0057
Inspection of cylinder bore

Measure the cylinder bore at specified positions with a
cylinder gauge.
Measurement position: 13 mm {0.512 in} lower from the
top surface.
(Measure in the X − X and Y − Y directions.)
(Near top ring)
mm {in}
Nominal Service limit Repairing procedure
dimension
φ85 φ85.2 Perform boring along the pis-
{3.3465} {3.354} ton and perform honing.
CAUTION:
• Oversized piston and piston ring are set to 0.25
mm {0.0098 in}.
• Be sure to perform honing after boring.
Honing should be at 0 to 0.03 mm {0 to 0.0012
in} against oversize diameter. Difference of
each cylinder bore should be 0.02 mm {0.0008
in} or less.
Inspection of top distortion
two diagonal directions, and measure the distortion
with the thickness gauge.
mm {in}
Y
X X Standard Abnormal value Repairing procedure
value (need repair)
Y
Repair it with a surface
grinder. The total amount
of repaired values of the
cylinder head and of the
0.075
cylinder block should not
{0.00295} or 0.15 {0.006}
exceed 0.3 {0.012}.
less
If the measured value
exceeds the maximum
repaired value, replace
the cylinder block.
WSLE0058
Cylinder bore diameter and grade mark

Grade mark is stamped to each installation surface of
the injection pump of the cylinder block.
mm {in}
Engine model Bore diameter Grade
φ85.000 — 85.010 A
{3.3465 — 3.3468}
φ85.011 — 85.020 B
4LE2X
{3.3469 — 3.3472}
φ85.021 — 85.030 C
{3.3473 — 3.3476}
WSLE0060
(Reference) Cylinder block height mm {in}

1 Engine model Standard value
4LE2X 307.94 — 308.06 {12.124 — 12.128}
WSLE0059
Name
1. Bore Grade Mark (Marking Position)
Installation
1. Install the crankshaft.
Refer to 1A-91, “Installation, Crankshaft”.
2. Install the camshaft.
Refer to 1A-85, “Installation, Camshaft”.
Refer to 1A-79, “Installation, Timing Gear Train”.
H 4. Install the crankshaft rear oil seal.
Refer to 1A-74, “Installation, Crankshaft Rear Oil
Seal”.
5. Install the crankshaft front oil seal.
Seal”.
7. Install the pistons and connecting rods.
WSLE0062 Refer to 1A-62, “Installation, Piston, Connecting
Rod”.
Refer to 1A-40, “Installation, Rocker Arm Shaft”.
10. Install the engine exterior equipment.
Equipment”.
11. Install the engine accessories.
Special Tool
List of Special Tool Illustration Tool No./Tool Name/Rank
Illustration Tool No./Tool Name/Rank
1-8522-1029-0
Piston ring setting tool
5-8840-2675-0 Rank B
J-26999-12
Compression gauge
Rank B
5-8840-9018-0
J-8037
Piston ring compressor
5-8840-9029-0 Rank B
Compression gauge adapter
Rank A
5884090290
5-8840-9031-0
Front oil seal installer
5-8840-9016-0 Rank A
J-28829
Nozzle tester
5884090310
Rank B
5884090160
5-8840-9032-0
Rear oil seal installer
5-8840-9030-0 Rank A
J-29760
5884090320
Rank B
5884090300
5-8840-9035-0
Rank B
5884090350
5-8840-9033-0
JKM-1009
Valve seal setting tool
Rank B
5884090330
4LE2 Cooling System 1B-1
Engine
4LE2 Cooling System
Table of Contents
Cooling System ..................................................... 1B-2
Service Precautions ........................................... 1B-2
Explanations on Functions and Operation ......... 1B-2
Function Check .................................................. 1B-4
Water Pump .......................................................... 1B-7
Components....................................................... 1B-7
Inspection........................................................... 1B-7
Thermostat ............................................................ 1B-8
Inspection........................................................... 1B-8
Fan Clutch, Cooling Fan ....................................... 1B-9
Inspection........................................................... 1B-9
1B-2 4LE2 Cooling System
Cooling System
Service Precautions Explanations on Functions and Operation
WARNING: Cooling water system
Do not remove the radiator cap when the cooling
The cooling water system, which is the forced circula-
water is at high temperature. Steam or boiling
tion system, consists of a water pump, thermostat, and
water will gush out and you may be burnt. To open
radiator as its main components.
the radiator cap, cover the cap with a thick cloth
when the cooling water is cool, release the pres-
sure by slowly turning the cap, and then remove
the cap.
3
2
1 4
7
6 5
WSLE0172
Name
1. Thermostat (Bottom Bypass type) 5. Cylinder Block
2. Oil Cooler 6. Water Pump
3. EGR Cooler 7. Radiator
4. Cylinder Head 8. Bypass Circuit
Water pump
The water pump, which uses the centrifugal impeller system, is driven by the engine fan belt.
1
2
WSLE0350
Name
1. Fan Center 3. Seal Unit
2. Impeller 4. Bearing Unit
Thermostat
The thermostat, which is a wax pellet type, has an valve initial opening temperature of 82±1.5°C {180±34.7°F}.
3
1
WSLE0349
Name
1. Valve 3. Jiggle Valve
2. Piston
Function Check Coolant

Cooling water level check 1. About the engine coolant concentration
• Check the cooling water level within the reserve • Take the concentration corresponding to the
tank and the level is appropriate when the cooling minimum temperature because the freezing
water level is within the MAX (upper limit) and MIN temperature varies according to the concentra-
(lower limit) range. In case the volume of the cool- tion of the engine coolant.
ing water is deficient, remove the reserve tank cap • Use only Isuzu genuine engine coolant.
and replenish with a mixture of tap water and • Use engine coolant with a mix ratio in the range
engine coolant in the ratio of 1:1 until the level of 30 to 60% because over heating is likely to
comes close to the MAX line. occur if the ratio is greater than 60% and corro-
sion prevention is inadequate if the ratio is less
Standard value
than 30%.
Cooling water level 4.3 L {4.5 qts}
(Engine only)
Cooling water leak check

• Use the radiator cap tester and apply a pressure of
200 kPa {29.0 psi} and check for leaks in the loca-
tions given below. Check that the radiator hose
and heater hose are not damaged or degraded
and the hose clamp is not loose.
Inspection location
• Radiator ASM, water pump ASM, radiator hose,
heater hose
• Fix the temperature of the cooling water being
Freezing Maximum mix ratio Concentration measured in the range of 0 to 50°C {32 to 122°F}.
temperature L {qts} of engine cool-
guideline ant
• Measure the temperature and specific gravity and
Engine Tap water determine the concentration from the table given
coolant below.
−18°C {−0.4°F} 4.2 {4.4} 7.8 {8.2} 35%
−25°C {−13°F} 5.0 {5.3} 7.0 {7.4} 42%
−35°C {−31°F} 6.0 {6.3} 6.0 {6.3} 50%
−40°C {−40°F} 6.4 {6.8} 5.6 {5.9} 53%
2. Engine coolant concentration measurement
Methods for measuring specific gravity

• Measure the specific gravity and the temperature
of the cooling water using an antifreeze hydrome-
ter and thermometer.
Take precautionary measures as the boiled cool-
ing water may gush out at high temperatures if the
cap is removed.
• Use a deep container to suit the height of the spe-
cific gravity meter.
Name
1. Antifreeze Hydrometer
2. Radiator
Coolant scope method
• Measure the concentration using the coolant
scoop.
EGR cooler air bleeding procedure

When replacing the coolant, bleed air from the EGR
cooler with the following procedure.
Note:
Be sure to replace the coolant when it is cooled.
1. Loosen the air bleed plug (1) on the EGR cooler.
WSLE0355
2. Pour coolant into the radiator via its opening.

3. Tighten the plug when the coolant spills over from
the air bleed plug.
• Replace the copper packing if it is faulty.
Note:
• Take care to prevent the spilt coolant from getting
the exhaust system parts wet.
• Be sure to wipe off the spilt coolant.
Tightening torque:
24.5 — 30.5 N⋅m {2.5 — 3.1 kgf⋅m/18.1 — 22.5
lb⋅ft}
4. Pour coolant into the radiator via its opening again
until it is filled.
5. Bleed air from the engine body coolant with idling
the engine.
Water Pump
Components
WSLE0173
Name
1. Water Pump
Inspection Inspection of the bearing rattle

Appearance check
Rattle of the water pump ball bearing mm {in}
• Check for cracks or damage in the pump body.
Standard value Service limit Repairing proce-
• Check for cracks and corrosion in the impeller. dure
• Check for water leakage from the seal unit.
0.008 — 0.010 0.2 {0.008} Replace.
• If you find abnormalities, replace the water pump {0.00031 — 0.00040}
ASM.
Inspection of bearing
• Rotate the fan center while pushing it along the
radial direction. Confirm that there is no abnormal
noise and no excessive play.
• If you find abnormalities, replace the water pump
ASM.
Thermostat
Inspection
Replace it if there is wear, damage, or other abnormal-
ity.
Open start temperature °C {°F} 82±1.5 {180±34.7}

Valve lifting height mm {in} 9.5 {0.374} or more
(95°C {203°F})
WSJJ0148
Name
1. Thermometer
2. Stirrer
3. A Piece of Wood
Fan Clutch, Cooling Fan

Inspection 2. Inspection (single unit)
If wear, damage or any fault is found during the inspec- a. Warm up the bimetal area of the fan clutch
tion, replace or repair as required. using a heat gun until the temperature reading
on the thermistor reaches approx. 85°C
Visually check for damage, silicon grease leakage or {185°F}. Then check if considerable force
other faults. (clutch torque) is required to rotate the fan
clutch.
1. Inspection (on-vehicle)
At this time, if the fan clutch rotates easily, this
a. Before starting the engine, rotate the fan clutch indicates that the silicon grease is leaked
when it is cold by hand to check if it rotates eas- inside. Replace the fan clutch with new one.
ily.
a. Start the engine and warm it up until the tem-
perature of the fan clutch reaches approx. 85°C
{185°F}. Then stop the engine, and rotate the
fan clutch by hand to check if considerable Heat gun
force (clutch torque) is required to rotate. How-
ever, if the fan clutch rotates easily, this indi-
cates that the silicon grease is leaked inside.
Replace the fan clutch with new one.
Thermistor WSJJ0279
WSJJ0278
4LE2 Fuel System 1C-1
Engine
4LE2 Fuel System
Table of Contents
Fuel System ..........................................................1C-2
Service Precautions ...........................................1C-2
Explanations on Functions and Operation .........1C-3
Governor ...............................................................1C-6
Service Precautions ...........................................1C-6
Components.......................................................1C-7
Disassembly.......................................................1C-9
Reassembly .....................................................1C-10
1C-2 4LE2 Fuel System
Fuel System
Service Precautions
Parts of the fuel system such as the internal part of the
nozzle holder, holes and clearances that form pas-
sages for fuel are finished to a very high degree of
accuracy. They are therefore highly sensitive to foreign
matter and the entry of foreign matter could cause
damage to the fuel passage. Take extreme care not to
allow foreign matter to enter.
If water removal agent is used in the fuel then it will
absorb moisture in the light oil and may cause rust.
Therefore, do not use water removal agent in the fuel
tank.
When servicing the fuel system, every precaution must
be taken to prevent the entry of foreign material into the
system.
• Before beginning the service procedure, wash the
fuel line and the surrounding area.
• Perform the service procedures with clean hands.
Do not wear work gloves.
• Immediately after removing the fuel hose and/or
fuel pipe, carefully tape vinyl bags over the
exposed ends of the hose or pipe.
• If parts are to be replaced (fuel hose, fuel pipe,
etc.), do not open the new part packaging until
installation.
Discard gaskets and O-rings and replace them with
new ones.
Work procedure
• The fuel opening must be quickly sealed when
removing the fuel pipe, injection pipe, nozzle
holder, and injection pump.
• The eyebolts and gasket must be stored in a clean
parts box with a lid to prevent adhesion of foreign
matter.
• Fuel leakage could cause fires. Therefore, after
finishing the work, wipe off the fuel that has leaked
out and make sure there is no fuel leakage after
starting the engine.
Explanations on Functions and Operation
Fuel system diagram
4
6
2
3
WSLE0180
Name
1. Fuel Tank 4. Injection Pump
2. Sedimenter 5. Nozzle Holder
3. Fuel Filter 6. Nozzle
Note:
• Be careful foreign material does not enter into the
fuel system, because the precise fuel system is
used.
Injection pump Nozzle holder
Note:
• Do not disassemble the injection nozzle installed
on this engine since it has the 2-stage open valve
pressure nozzle.
• If a overhaul of the nozzle and inspection and
adjustment of the injection pressure are required,
contact a BOSCH service center.
WSLE0328
WSLE0348
Name
Name 1. Nozzle
1. Rack Pin
Fuel filter
WSLE0327
Name
1. Cartridge
Sedimenter
WSLE0326
Name
1. Lever (Opening Position)
2. Lever (Closing Position)
3. Drain Plug
Governor
Service Precautions
1. Engine performance test is required for adjustment
of the governor-related parts.
2. Measure the dimensions of A and B in the struc-
ture diagram (1) before disassembling, and set
them to the same dimensions when reassembling.
3. When you cannot carry out a performance test
after reassembling, do not disassemble it.
4. Apply engine oil to each sliding portion (the lever
end surface, the shaft hole and the outer circum-
ference of the shaft) when reassembling it.
5. Install the set spring securely to a groove of the pin
connecting the floating lever, taking care of the
assembly direction.
6. Before installing the start spring, make sure that
each lever moves by its weight.
7. After installing the start spring, make sure that
each lever moves smoothly.
Also, make sure that each spring operates nor-
mally.
Components
Structure diagram (1)
3 5
A 6
2 7
1 8
22 9
21
10
20
11
19
B 12
18
13
17
14
16
15
WSLE0181
Name
1. Control Link 12. Tension Lever
2. Link Plate 13. Angleich
3. Start Spring 14. Full Load Stopper
4. Idle Speed Screw 15. Shifter
5. Idle Spring (Sub) 16. Flyweight
6. Fuel Cut Lever 17. Sleeve
7. Governor Shaft 18. Camshaft
8. Set Spring 19. Floating Lever
9. Governor Cover 20. Main Spring
10. Guide Lever 21. Lever (Main Spring)
11. Timing Gear Case 22. Injection Pump
Structure diagram (2)
18 20
17 19
16
15
A 21
14
22 23
13
24
12 26
B
8
25
9
A
11 27
7 29
10
5 6 28
30
4 A
35
34
33
3 2
B
31
32
36
1
WSLE0182
Name
1. Timing Gear Case 19. Snap Pin
2. Lever Bushing 20. Control Link
3. Control Lever 21. Link Plate
4. O-ring 22. Guide Piece
5. Speed Control Screw 23. Shifter
6. Speed Control Screw 24. Shaft (Floating Lever)
7. Start Spring Bracket 25. Shifter Shaft
8. Fuel Cut Shaft 26. Main Spring
9. Return Spring 27. Tension Lever
10. Idle Spring 28. Angleich
11. O-ring 29. Lever (Main Spring)
12. Fuel Cut Lever 30. Return Spring
13. Set Screw 31. Cam Gear
14. Cap Nut 32. Flyweight
15. Floating Lever 33. Sleeve
16. Guide Lever 34. Lever Bushing
17. Set Spring 35. Shaft
18. Start Spring 36. Full Load Set Screw
Disassembly
Disassembly of the governor lever-related
components
1. Remove the levers and spring from the timing gear
case.
Disassembly of the full load stopper

1. Remove the full load stopper from the timing gear
case.
Disassembly of the governor cover

1. Remove the fuel cut lever and the idle spring-
related components from the governor lever.
Disassembly of the shifter

1. Remove the snap ring and the shaft to remove the
shifter from the guide lever.
Disassembly of the control lever-related

components
1. Remove the nut to remove the control lever.
2. Take off the hook on the return spring from the pro-
jection of the lever (main spring) and pin.
3. Remove the bushing.
4. Remove the return spring.
5. Remove the lever (main spring).
Reassembly
Reassembly of the control lever-related components
1. Put the lever (main spring) through lever holes of the timing gear case.
CAUTION:
Put both axes of the lever through lever holes alternately before assembling the bushings.
2. Put the return spring of the control lever through a axis of the lever (main spring).
3. Assemble the bushing.
Assemble the bushing of the lever (main spring), and then assemble the bushing of the control lever.
CAUTION:
Apply Loctite (No.601) to the outer circle of the bushing when assembling the bushing.
6 7
3
2
4
5
WSLE0183
Name
1. Lever (Main Spring) 5. Timing Gear Case
2. Bushing 6. Bushing
3. Return Spring 7. Protrusion
4. Pin
4. Assemble the hooks on both ends of the return spring (control lever) to the protrusion of the lever (main spring)
and pin securely.
5. Assemble the control lever.
After installing the O-ring to a groove of the bushing (control lever), assemble the washer and the control lever,
and tighten the nut.
Tightening torque:
11.8 — 17.7 N⋅m {1.2 — 1.8 kgf⋅m/8.7 — 13.1 lb⋅ft}
1 4 6
7
WSLE0184
Name
1. Bushing 5. Control Lever
2. Groove 6. Spring Washer
3. O-ring 7. Nut
4. Washer
CAUTION:
• When tightening the control lever, fix the control lever.
(Fix the lever of the main spring. Do not over-tighten it.)
• After assembling, make sure that the control lever moves smoothly.
Reassembly of the shifter

1. Assemble the shifter to the guide lever, put the
shaft through it, and assemble the snap ring.
2. Make sure that the shaft rotates smoothly.
1
3. Make sure that the shifter moves smoothly.
4 WSLE0185
Name
1. Guide Lever
2. Shifter
3. Snap Ring
4. Shaft
Reassembly of the governor cover
Assemble the fuel cut lever and the idle spring-related components to the governor cover.
5 6
2 22 22
7
1 3
4 Z
9
12 10 8
14 11
13
Z
WSLE0186
Name
1. Folding Part 8. Idle Spring
2. Governor Cover 9. Nut
3. Return Spring 10. Spring Washer
4. Thrust Washer 11. Fuel Cut Lever
5. Stop 12. O-ring
6. Driving 13. Cutout Groove
7. Governor Cover 14. Shaft
1. Apply engine oil to the sliding surface of the gover-

nor cover when assembling the shaft.
2. Assemble the both ends of the return spring to the
cutout groove on the bottom of the cover and the
folding part of the lever securely.
3. After assembling, make sure that it moves
smoothly.
4. When assembling the governor cover to the timing
gear case, temporarily tighten it with dimension A
in the diagram 2 — 3 mm {0.079 — 0.118 in}.
Assemble B part after the performance set.
mm {in}
Dimension A (When temporarily assembling) 2 — 3
{0.079 — 0.118}
Arrow view of WSLE0186 Reassembly of the full load stopper
Install the full load stopper to the timing gear case, and
temporarily tighten the nut.
1
2
4
1
B
5
A
6
2
7
3
8
12
9
11 10
WSLE0187
Name
1. Cap
WSLE0188
2. Cap Nut
3. Packing Name
4. Lock Nut 1. Timing Gear Case
5. Packing 2. Full Load Stopper
6. Idle Screw 3. Set Screw Nut
7. Governor Cover
8. Tension Lever
9. Idle Spring
10. Snap Ring
11. Washer
12. Washer
Reassembly of the governor lever-related components
Assemble each lever and the spring to the timing gear case.
8
6
9
7
10
4
11
12
3
1
2 13
14
WSLE0189
Name
1. Plug 8. Main Spring Lever
2. Shaft (Floating Lever) 9. Tension Lever
3. Snap Piece 10. Main Spring
4. Guide Piece 11. Set Screw
5. Start Spring Eye 12. Start Spring
6. Lever Shaft 13. Guide Lever
7. Link Plate 14. Floating Lever
4LE2 Electrical System 1D-1
Engine
4LE2 Electrical System
Table of Contents
Charging System...................................................1D-2
General Description ...........................................1D-2
Maintenance.......................................................1D-3
Generator (24V-30A).............................................1D-4
Structure.............................................................1D-4
Removal .............................................................1D-5
Installation ..........................................................1D-5
Torque Specifications.........................................1D-6
Specifications .....................................................1D-7
Connector Terminal............................................1D-7
Internal Connections ..........................................1D-7
Components.......................................................1D-8
Disassembly.......................................................1D-9
Inspection.........................................................1D-11
Reassembly .....................................................1D-12
Bench Test .......................................................1D-12
Trouble Diagnosis ............................................1D-14
Maintenance Standard .....................................1D-14
Generator (24V-50A)...........................................1D-15
Structure...........................................................1D-15
Removal ...........................................................1D-16
Installation ........................................................1D-16
Torque Specifications.......................................1D-17
Specifications ...................................................1D-18
Connector Terminal..........................................1D-18
Internal Connections ........................................1D-18
Disassembly.....................................................1D-19
Inspection.........................................................1D-20
Bench Test .......................................................1D-22
Handling ...........................................................1D-24
Trouble and Action ...........................................1D-24
Starting System...................................................1D-25
General Description .........................................1D-25
Service Precautions .........................................1D-26
List of Trouble Symptom ..................................1D-26
Specifications ...................................................1D-27
Sectional View..................................................1D-28
Starter .................................................................1D-29
Components.....................................................1D-29
Removal ...........................................................1D-29
Installation ........................................................1D-29
Torque Specifications.......................................1D-30
Disassembly.....................................................1D-30
Inspection.........................................................1D-32
Reassembly .....................................................1D-35
No Load Test....................................................1D-38
Maintenance Standard .....................................1D-38
1D-2 4LE2 Electrical System
Charging System
General Description
The main charging system components are the batteries, the generator and the battery charge indicator light circuit.
The generator is a self-rectifying type with a built-in regulator.
1 2 3 4
WSLE0373
Name
1. Nut 5. Tension Adjusting Bolt
2. Sliding Piece 6. Generator
3. Generator Adjusting Plate 7. Lower Mounting Bolt
4. Adjusting Nut
Maintenance Electrical tests
The most common indication of charging system trou- Before performing the following generator electrical
bles is an undercharged or overcharged battery. tests on the vehicle, be certain that the system wiring is
Since the battery itself may be defective, check the bat- not defective and generator belts are not slipping. Also,
tery first. Check if the battery is discharged because of the battery must be fully charged for a valid test of the
short circuit, or electrical components left turned on for charging system.
extended periods.
Keep the generator and all other electrical system ter- Note:
minals clean and tight. A loose or badly corroded termi- To avoid damage to the vehicle electrical system,
nal connection will create excessive resistance in the always observe the following precautions:
circuit and result in hard starting, dim lights, etc. • Do not polarize the generator.
Inspect the generator system at regular intervals and • Do not short across or ground any of the terminals
correct any potential causes of trouble before machine in the charging circuit.
performance is affected.
• Never operate the generator with the output termi-
nal open-circuited.
Diagnosis of charging system
• Be sure the generator and battery have the same
Trouble in the charging system will be evidenced as ground polarity.
one or more of the following three conditions:
• When connecting a charger or other battery to the
1. The battery charge warning lamp will stay on. machine's battery, connect negative to negative
2. An undercharged battery as evidenced by slow and positive to positive.
cranking.
3. An overcharge, or overvoltage, condition. 1. With the engine control switch “ON” and engine not
running, connect a voltmeter from terminal “E” to
Undercharged battery ground. The voltmeter should show 0 volts.
Inspection 2. With the engine control switch “ON” and engine not
running, connect a voltmeter from terminal “B” to
1. Accessories were not left turned on for extended
ground. The voltmeter should show 24 volts or
periods.
more.
2. Drive belt for proper tension.
3. With the engine control switch “ON” and the engine
3. The ECM main relay has been stuck ON with the not running, connect a voltmeter from white wire
key switch in OFF position. (Battery voltage is con- side of the connector to ground. The voltmeter
sumed.) should show 24 volts or more.
4. Wiring and connections for corrosion or looseness. 4. With the engine control switch “ON” and the engine
not running, the “charge” light should be on. This
Overcharge (or Overvoltage) condition shows that the current is running into the initiating
A charging rate in excess of 29.5 volts for a prolonged excitation circuit to the generator.
period may cause early electrical system failure. 5. With the engine running and the headlight high
Blown fuses, light bulbs burned out, and even battery beams (if equipped) turned on, read the voltage at
failure may result. If this condition exists, test the gen- the “B” post on the generator. The voltmeter
erator as described under “Generator Output Test” later should show 24 volts or more.
in this section.
6. If steps 1 through 4 are not OK, check connectors
Noisy generator in the harness for looseness or corrosion and
retest.
Inspection
7. If step 5 voltage is low, substitute a known good
1. Drive pulley for looseness. regulator and test again. If the voltage is still low,
2. Mounting bolts for looseness. bench test the generator.
3. Bearings for dirt, damage, or wear.
Generator noise may also be caused by the loose
belt, core touch, or worn or damaged diodes and/
or starter.
Generator (24V-30A)
Structure
WSLE0387
7 70
65
6 60
55
5 50
45
DRIVING TORQUE (N.m)
OUTPUT CURRENT(A)
4 40 COLD
35 DRIVING TORQUE
(HOT REF.)
3 30
25 HOT
2 20
15
1 10
IC REGULATOR
5
0 0
0 1 2 3 4 5 6
GENERATOR SPEED (X1000r/min)
WSLE0388 WSLE0397
• Battery ground cable 1. Generator
1. Electrical wiring at the generator. • Tighten the lower mounting bolt while holding
2. Loosen the adjusting nut. the nut located on the back using a tool.
3. Loosen the ACG adjusting bolt. Tightening torque:
4. Loosen the lower mounting bolt. Lower mounting bolt: 18.6 — 28.4 N⋅m {1.9 —
2.9 kgf⋅m/13.7 — 20.9 lb⋅ft}
• Loosen the lower mounting bolt while holding
the nut located on the back using a tool. 2. ACG adjusting bolt.
5. Drive belt. 3. Adjusting nut.
6. Generator. Tightening torque:
Adjusting nut: 18.6 — 28.4 N⋅m {1.9 — 2.9 kgf⋅m/
13.7 — 20.9 lb⋅ft}
4. Electrical wiring at the generator.
• Battery ground cable
• Install wiring (AV5.0 mm2, black) from the neg-
ative terminal of the generator to the engine
ground and connect it to ground securely.
N m (kg m / lb ft)
18.6 - 28.4 (1.9 - 2.9 / 13.7 - 20.9)
18.6 - 28.4 (1.9 - 2.9 / 13.7 - 20.9)
18.6 - 28.4 (1.9 - 2.9 / 13.7 - 20.9)
WSLE0399
Specifications Connector Terminal
Isuzu Part No. 8971822892 Terminal symbol Lead wire color Wire specifica-
tions
Nominal output (V-A) 24-30
R R AEX 0.75f
Rated speed (r/min) 5,000
L L AEX 0.75f
Regulator-type IC type
Regulated voltage (V) 28.5±0.5
Mass (kg) 5.1
1 2
WSLE0398
Name
1. R Terminal
2. L Terminal
Internal Connections
IC REGULATOR
WSLE0389
Components
3 2
4
6 5
1
11
10
13
12
7
WSLE0390
Name
1. Pulley 8. Cover
2. Rear Bearing 9. Brush
3. Rotor 10. Regulator and Brush Holder
4. Retainer 11. Packing
5. Front Bearing 12. Rectifier
6. Front Bracket 13. Rear Bracket
7. Stator
Disassembly
CAUTION:
To facilitate re-assembly, put alignment marks on
front bracket and rear bracket before disassembly.
1. Remove out the four through bolts.

Pry between stator and front bracket with a tip of
flathead screwdriver and separate the front bracket
pulley rotor assembly from stator rear bracket
assembly carefully.
CAUTION:
Take care not to damage the stator coil.
2. Hold the rotor with a vise without deforming the

rotor pole.
Remove the pulley fixing nut, and remove the pul-
ley, spacer and front bracket.
CAUTION:
To hold the rotor with a vise, grip the portion A.
Portion B is not strong enough to be gripped.
WSLE0391
3. If the front bearing needs to be removed, remove

the screw which fixes retainer, and push out the
bearing using appropriate socket.
CAUTION:
Do not remove it if not necessary. Do not reuse the
removed bearing.
4. If the rotor bearing needs to be removed, it can be

done by a general bearing puller.
CAUTION:
Do not remove it if not necessary. Do not reuse the
removed bearing.
1 3
WSLE0392
Name
1. IC Regulator 3. B Terminal
2. Rectifier 4. Nut
5. Remove one rectifier fixing screw, B terminal nut 7. Remove the soldering part indicated in the illustra-
and two regulator fixing screws. tion from the rectifier, and then remove the regula-
Remove the stator and rectifier assembly from rear tor and the brush holder.
bracket as a unit.
Then, remove the IC regulator.
6. Disconnect three lead wires of stator coil and
remove the stator from rectifier.
CAUTION:
1
Lead wires of stator coil are soldered (melting
point: 230°C {446°F}) on rectifier terminal.
Disconnect them quickly (within five seconds) not
to heat the rectifier causing damage to diode.
WSLE0393
Name
1. Regulator and Brush Holder
2. Rectifier
Inspection Rotor
Stator • Check the bearings for noise, rattle or grease leak-
age (wipe off if tiny amount of grease). Replace it if
Check visually for damage, loose connection and dis-
faulty. It is easier to check for noise and rattle
coloration of coil.
when it is press-fitted into shaft than when it is a
• Check for continuity between two lead wires of sta- single unit.
tor coil with a circuit tester. Replace the stator if no
• Measure the resistance value between slip rings.
continuity is present.
If the measured value deviates from the standard
value, replace the rotor.
WSLE0394
Name
WSHK0400
1. Stator Coil Lead
• Check for continuity between the slip ring and the
• Check for continuity between lead wire of stator core.
coil and core with a circuit tester. Replace the sta- Replace the rotor as short occurs when continuity
tor if continuity is present. is present.
WSHK0416
WSLE0395
Name
1. Stator Coil Lead
2. Core
Rectifier assembly Regulator
• Check that the diode inside of the rectifier operates The regulator cannot be checked with a circuit tester.
properly with a circuit tester. After re-assembling the generator, check it to make
• Check the diode in both directions by exchanging sure that regulator controls the voltage for generator.
(+) side and (−) side. if abnormality is found,
replace the rectifier assembly.
If resistance value is infinity in both directions, the
Reassembly
diode is open. Assembly can be performed in the reverse order of dis-
If resistance value is almost the same as 0 Ω in assembly. However, be careful with the following.
both directions, the diode is short. 1. Lubrication is not necessary. Bearing is filled with
grease and is sealed.
Note:
As normally the current flowing to the rectifier is low, CAUTION:
tester may indicate the resistance value that is not Keep a bearing with resin band for rotor shaft away
clear. from oil. Wipe off oil on bearing box area of rear
Also, this is more likely to occur as smaller range is bracket. Oil may cause creep.
used for the tester. Use range as large as possible.
2. Use a high temperature solder (melting point:
230°C {446°F}).
Using a soldering iron (with 180 — 270 watt), sol-
dering must be performed quickly (within five sec-
4 6 onds) not to heat the rectifier.
• Pulley fixing nut:
98 — 137 N⋅m {10.0 — 14.0 kg⋅m/72 — 101
lb⋅ft}
• Through bolt:
3.4 — 5.4 N⋅m {34.7 — 55.1 kg⋅cm/30 — 48
lb⋅in}
• Bearing retainer fixing screw:
1 2 3 2.9 — 4.9 N⋅m {29.6 — 50.0 kg⋅cm/26 — 43
lb⋅in}
• Rectifier fixing screw:
2.9 — 4.9 N⋅m {29.6 — 50.0 kg⋅cm/26 — 43
lb⋅in}
• Regulator fixing screw:
2.9 — 4.9 N⋅m {29.6 — 50.0 kg⋅cm/26 — 43
lb⋅in}
• Nut for B terminal bolt:
4.9 — 8.8 N⋅m {50.0 — 89.8 kg⋅cm/43 — 77
lb⋅in}
5 4. Assembly of rear bracket to stator assembly and
front bracket to rotor assembly
WSLE0396 • The rotor bearing and rear bracket are engaged
Name tightly. Heat the bearing box area of rear
1-3. Connection of Lead Wire of Stator Coil bracket to 50 — 60°C {122 — 140°F} prior to
4.5. Heat Sink assembly.
6. Connection of Regulator • After re-assembling the generator, rotate the
pulley to confirm that the rotor rotates smoothly.
Front bearing
Check the bearings for noise, rattle or grease leakage Bench Test
(wipe off if tiny amount of grease). Replace them if Bench test is performed as follows.
faulty. It is easier to check for noise and rattle when the
bearing is press-fitted into bracket than when it is a sin-
gle unit.
Regulated voltage check Output current test
1. Wire as shown in the illustration. Output current test is performed to check if the genera-
Use an ammeter with 100 A rating and a voltmeter tor generates rated output.
with 30 V rating. 1. After checking regulated voltage, decrease the
generator speed until it stops.
2. Close the switch 1. The lamp should come on.
3. Set the value of no load resistance to maximum
(minimum current) and close the switch 2.
2 4 4. Increase the generator speed to 5,000 r/min and
keep it. Adjust the load resistance so that output
A current becomes maximum.
3 6 Keep this condition for 15 minutes and increase in
B temperature of the generator.
L
R 15 minutes later, set the generator speed to the
1 V 8 5 7 specified speed (1,800 r/min) and then adjust the
load resistance so that output current becomes
maximum in this condition.
In this time, if indication of ammeter is within speci-
fied value, the generator is normal.
If it is the specified value or less, check the genera-
tor again according to “Inspection”.
WSHK0100
Name
1. Voltmeter
2. Ammeter
3. Lamp (24 V, 3 W or less)
4. Switch 1
5. Battery (24 V)
6. Switch 2
7. Load Resistance
8. Generator
2. Close the switch 1. Leave the switch 2 open.

In this time, the lamp comes on.
If it does not, check the voltage on L terminal.
If the voltage is almost the same as battery volt-
age, check the generator.
If the voltage is low, lamp or the circuit is open.
3. Increase the generator speed gradually.
Make sure that the lamp goes off before the speed
reaches approx. 1,300 r/min.
Notice the voltage. If the voltage is not controlled
and exceeds 30 V, the IC regulator may be faulty.
If the voltage does not exceed battery voltage, the
generator does not generate electric power.
Check the generator again.
If the lamp does not go off, check the generator
again.
4. Set the generator speed to approx. 5,000 r/min
and read an ammeter. If the value is 5 A or less,
read indication on a voltmeter. This is regulated
voltage.
If an ammeter shows 5 A or more, keep charging
for a while until it shows below 5 A or replace the
battery with full-charged one.
If regulated voltage is out of specified value,
replace the regulator.
Trouble Diagnosis
Symptom Trouble cause

No generation of elec- a. Defective IC regulator
tric power b. Open circuit in field coil
Output shortage a. Defective diode
b. Defective stator coil
c. Defective rectifier
d. Internal short circuit in field coil
Too high regulated a. Defective IC regulator
voltage
Noise a. Defective bearing
b. Defective rectifier
c. Foreign material in generator
Maintenance Standard
Item Standard value and limit

Isuzu Part No. 8-97182-289-2
Manufacturer code No. A002TA8383
Rated output V-A 24-30
Output characteristic Voltage V 27
(hot)
Current A 18 or more
Revolution r/min 1,800
speed
Field coil resistance Ω: at 20°C 6.4 — 7.6
Regulated voltage by regulator V 28-29
Revolution direction (viewed from pulley side) Clockwise
Generator (24V-50A)
Structure
WSLE0367
• Battery ground cable 1. Generator
1. Electrical wiring at the generator. • Tighten the lower mounting bolt while holding
2. Loosen the adjusting nut. the nut located on the back using a tool.
3. Loosen the ACG adjusting bolt. Tightening torque:
4. Loosen the lower mounting bolt. Lower mounting bolt: 41.2 — 55.0 N⋅m {4.2 —
5.6 kgf⋅m/30.4 — 40.6 lb⋅ft}
• Loosen the lower mounting bolt while holding
the nut located on the back using a tool. 2. ACG adjusting bolt.
5. Drive belt. 3. Adjusting nut.
6. Generator. Tightening torque:
Adjusting nut: 18.6 — 28.4 N⋅m {1.9 — 2.9 kgf⋅m/
13.7 — 20.9 lb⋅ft}
4. Electrical wiring at the generator.
• Battery ground cable
• Install wiring (AV5.0 mm2, black) from the neg-
ative terminal of the generator to the engine
ground and connect it to ground securely.
N m (kg m / lb ft)
18.6 - 28.4 (1.9 - 2.9 / 13.7 - 20.9)
18.6 - 28.4 (1.9 - 2.9 / 13.7 - 20.9)
41.2 - 55.0 (4.2 - 5.6 / 30.4 - 40.6)
WSLE0374
Specifications Connector Terminal
Isuzu Part No. 8980890630 Terminal symbol Lead wire color Wire specifica-
tions
Nominal output (V-A) 24-50
R R AEX 0.75f
Rated speed (rpm) 5,000
L L AEX 0.75f
Regulator-type IC type
Regulated voltage (V) 28.5±1
Mass (kg) 9.2
1 2
WSHK0101
Name
1. R Terminal
2. L Terminal
Internal Connections
SG L
IC
REGULATOR
WSHK0102
Disassembly
Disassembly procedure
5
6
7
8 3 12
11
10
9 13
18
15
14
19
23
21
20
2
1
17
16
22
WSLE0369
Name
1. Screw 13. Collar
2. Cover 14. Ball Bearing
3. Through Bolt 15. Rotor Assembly
4. Rotor, Front Bracket Assembly 16. Screw
5. Nut, Washer 17. Field Coil Assembly
6. Pulley 18. Stator Assembly
7. Fan 19. Holder
8. Collar 20. Regulator Assembly
9. Screw 21. Bolt (B Terminal)
10. Retainer 22. Condenser
11. Ball Bearing 23. Rectifier Assembly
12. Front Bracket
Assembly is the reverse order of disassembly.
Inspection Diode for initiating excitation, resistor
Diode Check for continuity between connector terminals R
and L with a tester (at Ω × 100 range). Normal diodes
Check for continuity of forward and inverse directions
and resistors show low resistance in forward direction
with a tester. Normal diodes show low resistance in for-
and high resistance in inverse one.
ward direction and high resistance in inverse one.
Judge that they are faulty other than those above.
WSHK0106
WSHK0104
Condenser
Charge the condenser with a tester (at Ω × 1000
range), and connect a tester lead inversely. Judge it as
normal if the needle on a meter deflects a little and
returns to the original position.
WSHK0105
Field coil Stator coil
• To judge the insulating condition of field coil, mea- • To judge the insulating condition of stator coil,
sure between the protrusion portions and core of measure between the stator coil and core with a
the coil with a tester (at Ω × 1000 range). Judge as tester (at Ω × 1000 range). Judge as faulty if it has
faulty if it has continuity. continuity.
WSHK0107 WSHK0109
• Measure between the protrusion portions of field • Judge as normal if there is continuity between N
coil with a tester, and judge as normal if the resis- lead of stator coil and three leads.
tance is about 6.7Ω (20°C {68°F}).
WSHK0110
WSHK0108
Bearing
• Check if the bearing rotates smoothly or has no
noise.
If the result of the inspection is unsatisfactory,
replace the bearing.
WSHK0111
Rotor
• Measure the outside diameter of the shaft at the
bearing mounting part.
• Replace the rotor if the measurement exceeds limit
value.
mm {in}
Standard value Service limit Repairing
procedure
Front 24.996 — 25.005 24.95{0.982}
{0.9841 — 0.9844}
Replace.
Rear 16.996 — 17.012 16.95 {0.667}
{0.6691 — 0.6698}
Bench Test
In the performance test of generator, connect as fol-
lows and measure the regulated voltage and output
current.
Actual wiring diagram for performance test of IC regulator built-in generator
Disassembly procedure
2 3 SW 1 SW 2
V 1
6 7
WSLE0368
Name
1. Voltmeter 5. Clamp Tester Ammeter
2. R Terminal 6. Battery 24 V
3. L Terminal 7. Variable Resistor
4. Charging Lamp 24 V-3 W
Regulated voltage measurement of regulator Measurement of the output current

Close SW1 switch, and warm-up five to ten minutes at Close SW1 and SW2 switches, and raise the generator
approx. 1500 rpm in generator until an ammeter shows speed to 5000 rpm. While keeping the voltmeter show-
6 A or less. ing 27 V, measure the maximum value of output current
After confirming that an ammeter shows between 2 and with a variable resistor.
6 A, set the generator between approx. 3000 to 4000 In this time, judge as normal if the output current is 50
rpm. If an voltmeter shows between 27.5 and 29.5 V, A or more.
the regulated voltage of regulator is normal.
If the ammeter shows 6 A or more, charge the battery Note:
for a while or replace it with full-charged battery. • Do not cut off battery circuit during generator rotat-
Replace the regulator if the voltmeter shows out of ing.
range between 27.5 and 29.5 V. • Do not connect to L terminal if the charging lamp
(24 V-3 W) is not used.
Specified value of regulated voltage
Never connect L terminal and B circuit directly.
27.5 — 29.5 V (+25°C {77°F}) Diode for excitation may be broken.
• The electrical load from the L terminal should be
1.0 A or less continuously.
Handling • Do not open/close the battery relay switch while
the engine runs.
Be careful with the following when handling a genera-
tor. • Disconnect the battery terminal when charging
from external source such as quick charge.
• Connecting the polarities of battery inversely
causes generator diode to be broken. • Do not pour steam cleaner or water directly on it.
• While the engine runs, Never disconnect the wiring • After connecting to B terminal and E terminal,
of battery terminal and charging circuit. tighten them to the following torque.
B terminal: 4.9 — 6.9 N⋅m {50.0 — 70.4 kgf⋅cm/
• Wiring connection to terminal must be performed
43.4 — 61.1 lb⋅in}
properly according to terminal symbol.
E terminal: 4.9 — 6.9 N⋅m {50.0 — 70.4 kgf⋅cm/
• Do not perform megger test on semiconductor 43.4 — 61.1 lb⋅in}
device.
• Refer to 1A-4, “Function Check, ISUZU Diesel
• Be sure to disconnect the battery terminal (−) Engine” for tension adjustment of the v-belt.
before inspection on equipment.
Trouble and Action
Trouble symptom Trouble location Trouble cause Action to be

taken
Charging is impossi- Wiring and ammeter Open or short circuit, disconnection Repair.
ble.
Generator Open circuit, short to ground, short circuit in each coil Replace.
Broken diode Replace.
Regulator Defective regulator Replace.
Poor contact in terminal of regulator Repair.
Insufficient charging Wiring Open or short circuit, looseness in connection Repair.
Generator Looseness of generator drive belt Repair.
Layer or short circuit in field coil Replace.
Layer or short circuit in stator coil Replace.
Defective diode Replace.
Poor contact in each terminal Repair.
Overcharging Regulator Defective regulator Replace.
Unstable charging Wiring Intermittent contact or nearly disconnected connection in wiring Repair.
current
Generator Looseness of generator drive belt Repair.
Short circuit or nearly disconnected connection in field coil Repair.
Short circuit or nearly disconnected connection in stator coil Repair.
Poor contact in each terminal Repair.
Noisy generator Generator Improper installation of generator Repair.
Defective bearing Replace.
Contact of rotor core and stator core Repair.
Defective diode Replace.
Short circuit in stator coil Replace.
Starting System
General Description
The starter output is 3.2 kw.
1
WSLE0385
Name
1. Starter
Service Precautions 2. Precautions on starting
Handling of starter • Be careful with charging status of battery. Insuf-
ficiently-charged battery causes starting trou-
1. Precautions on handling ble.
• Improper gap between pinion and ring gear • After checking engine starting, turn off the
causes faulty mesh. (Gap 2 — 3.5 mm {0.079 starter switch immediately.
— 0.138 in})
• One continuous use should be less than 10
Also, the front bracket is installed on the engine
seconds. If re-starting is needed, wait until the
side securely.
pinion stops completely.
• Be sure to turn off the battery switch before
• If the starter does not stop rotating when the
removal/installation of starter.
starter switch is turned off, turn off the battery
• Tightening/inserting wiring must be performed switch immediately. In this case, check the wir-
properly. Looseness causes starting trouble ing, switch, etc.
due to high contact resistance.
Condition Possible cause Correction

Starter does not operate when starter switch is Full discharge of battery Replace the battery.
turned on. Open circuit, poor contact Repair.
Poor contact in starter switch or Repair or replace it.
defective tightening of terminal
Poor contact in starter relay or Repair or replace it.
plug terminal
Short or open circuit in magnetic Replace.
switch coil
Pinion moves forward but it does not engage with Insufficient capacity of battery Charge the battery.
ring gear. Wear of pinion or ring gear tooth Replace the pinion or the ring
edge gear.
Dust on pinion shaft Repair.
Pinion engages and rotates motor but it does not Slippage of clutch Replace the clutch or the starter.
run engine. Breakage of reduction gear Replace the gear or the starter.
Pinion engages but it does not run engine. Insufficient capacity of battery Charge the battery.
Defective tightening of wiring cir- Repair.
cuit terminal
Short circuit of armature or field Replace the starter.
coil
Contamination of commutator Repair, or replace the starter.
Fatigue or wear of brush spring Replace the brush spring or the
brush.
Locking of bearing Replace the bearing or the starter.
Poor contact in magnetic switch Replace the magnetic switch.
When turning starter switch off after engine starts, Returning failure of starter switch Replace the starter switch.
starter does not stop. contact
Returning failure of starter relay Replace the starter relay.
contact
Short circuit in magnetic switch Replace the magnetic switch.
coil
Specifications
Manufacturer Mitsubishi Electric Co.

Isuzu Part No. 898072-3151
Manufacturer code No. M008T81571
Power output V-kW 24-3.2
Rating Sec 30
Outside diameter of yoke mm/in 81.6/3.213
Revolution direction Clockwise
Reduction mechanism Planetary gear
Weight kg 5.8
Pinion Module 3.0
Pressure angle 14.5
The number of teeth 11
Gear ratio {ring gear/pinion gear} 9 {99/11}
No load Voltage V 23
Current A 80 or less
Revolution speed r/min 3,750 or more
Restraint Voltage V 8
Torque N⋅m {kgf⋅m} 47.07 {4.8} or more
Pinion engagement voltage V 16.0 or less
Sectional View
Reference
6 7
8
3
1
13 12 11
10
WSLE0376
Name
1. Through Bolt 8. Pinion
2. Bearing 9. Bearing
3. Rear Bracket 10. Front Bracket
4. Brush Holder 11. Gear
5. Magnetic Switch 12. Yoke
6. Shift Lever 13. Armature
7. Gear Shaft
Starter
Components
17
18
21
20
9
27
28
6 29
13
15
16
14 5
19
26 8
4 22 10
3 25
2 24 12
1
23
30
11
WSLE0377
Name
1. Snap Ring 16. Packing
2. Stop Ring 17. Packing
3. Pinion 18. Plate
4. Pinion Spring 19. Planetary Gear
5. Lead Wire with Terminal 20. Lever
6. Screw 21. Lever Spring
7. Magnetic Switch 22. E-shaped Retaining Ring
8. Screw 23. Overrunning Clutch
9. Through Bolt 24. Internal Gear
10. Rear Bracket 25. Washer
11. Yoke Assembly 26. Gear Shaft
12. Brush Holder 27. Front Bracket
13. Armature 28. Bearing
14. Ball 29. Washer
15. Plate 30. Brush
1. Battery ground cable from the battery. 1. Starter.
2. Cables and electrical leads from the starter. 2. Two mounting bolts.
3. Two mounting bolts. Tightening torque:
4. Starter. Mounting bolt: 93.2 — 113 N⋅m {9.5 — 11.5 kgf⋅m/
68.7 — 83.3 lb⋅ft}
3. Cables and electrical leads to the starter.
4. Battery ground cable to the battery.
N m (kg m / lb ft)
93.2 - 113 (9.5 - 11.5 / 68.7 - 83.3)
WSLE0386
Disassembly
CAUTION:
Before disassembling the starter, put alignment
marks on each magnetic switch, yoke, front bracket SW 1 B
and rear bracket to facilitate re-assembly. S
M
Note:
In normal condition, if tap the pinion or stop ring toward Battery SW 2
the front bracket side, the front bracket will be broken. 24V
Therefore, tap the stop ring when the pinion comes out
to cranking position. Disconnect the lead wire
(attached with terminal)
from the M terminal.
1. Remove the nut on M terminal of magnetic switch
and the lead wire with terminal as shown in the
illustration, and connect the starter to the battery. Wiring diagram to move pinion forward
When closing the switches SW1 and SW2, the pin-
ion move forward to the cranking position and the
armature rotates.
WSLE0378
Then, open the switch SW2 to stop the armature
rotating.
Note:
Remove the pinion within 10 seconds since heat is
generated during electric discharge.
2. Apply the pipe, which just fits the stop ring, on the 9. Remove the internal gear, gearshift, overrunning
ring and tap the pipe with a hammer to remove the clutch and lever as a unit from front bracket.
stop ring toward the pinion side once. 10. Remove the lever.
Then, remove the snap ring and remove the stop
ring, pinion and pinion spring. CAUTION:
Remember the direction of lever.
CAUTION:
Do not reuse the snap ring. 11. Remove the two E-shaped retaining rings.
To remove the overrunning clutch, rotate the spline
by one tooth to remove it from gearshift assembly.
CAUTION:
Do not reuse removed E-shaped retaining ring.
5
12. Remove the internal gear.
4
In this time, take out one washer which adjusts
3 axial play of gearshift.
6
2
1
WSLE0379
Name
1. Pinion
2. Clutch Shaft
3. Snap Ring
4. Stop Ring
5. Pipe
6. Pinion Spring
3. Remove the screw of the magnetic switch, then

remove the magnetic switch.
CAUTION:
Tightening screw is tight. Use a shock driver to
loosen.
4. Remove the brush holder-tightening screw and

through bolt.
5. Apply a socket (outside diameter 32 mm {1.260
in}) on a commutator of armature.
Then, slide the brush on the socket, and remove
the yoke assembly with the brush rested on the
socket.
This facilitates to re-assemble.
6. Remove the brush from brush holder by pulling up
the brush spring, and then remove the brush
holder.
7. Remove the armature.
Remove a bearing using a general puller.
8. Remove the plate in planetary gear and remove
the packing.
Then, remove the packing and plate on the lever
support.
Inspection • Check the outside of commutator for wear.
Replace the armature if wear exceeds limit.
1. Armature
• Check the armature coil for internal short circuit
with a growler tester.
Replace the armature if internal circuit is
present.
WSHK0076
• Check the depth (undercut) of insulating mold
of commutator.
Remove abrasion powder on brush, and repair
if faulty.
WSHK0074
• Check the armature coil for grounding (faulty
insulating) with a circuit tester.
Replace the armature if grounding is present.
2
3
WSHK0077
Name
1. Good
2. Insulating
WSHK0075 3. Commutator Segment
4. Defective
• Check the gears for wear or damage.

Replace the armature if fault is present.
• Check the bearings for noise, rattle or grease
leakage.
2. Field coil 3. Brush
• Check the coil for open circuit with a circuit • Measure the length of the brush.
tester. If it is worn to the limit, replace the brush holder
Replace the yoke assembly if open circuit is assembly on the brush holder as a unit and only
present. brush on the yoke assembly side.
• Make sure the brush moves smoothly in the
brush holder. Also, check the brush spring
pressure.
• Check the brush holder for grounding (faulty
insulating) with a circuit tester.
Clean the brush holder before checking.
Replace the brush holder assembly if the conti-
nuity is present when putting one probe of cir-
cuit tester to brush holder plate (metal part) and
another one to insulated holder.
WSHK0078
• Check the coil for grounding (faulty insulating) 1
with a circuit tester.
Repair or replace the yoke assembly if ground-
ing is present.
WSHK0080
Name
1. Brush Length
2. Insulated Holder
WSHK0079
4. Overrunning clutch and pinion 7. Lever
Hold the housing of overrunning clutch by hand. If the portion which contacts the overrunning
Make sure that the pinion can be rotated by hand switch is worn, the protruded position of pinion will
with a light resistance in one direction and cannot be faulty.
be in the opposite direction. Replace the overrun- (Refer to 1D-35, “Reassembly, Starter” to adjust
ning clutch if faulty. the protruded position of pinion.)
Check the pinion, and replace it if wear or scratch
is present.
CAUTION:
Grease is present in overrunning clutch. Do not
use wash oil or cleaning agent for cleaning.
Wipe off stain on overrunning clutch with a cloth.
WSLE0380
Name
1. Worn Part
8. Magnetic switch
Check for continuity between the M terminal and
the body, and replace the magnetic switch if no
continuity is present.
WSHK0081 Then, make sure that no continuity is present
5. Front bracket between B terminal and M terminal. Replace the
Check the bearing and oil seal, and replace the magnetic switch if continuity is present.
front bracket assembly (including bearing, oil seal)
if faulty.
3
6. Internal gear and planetary gear
Check the internal gear and planetary gear, and
replace them if excessive wear or damage is
present.
1
WSLE0381
Name
1. M Terminal
2. S Terminal
3. B Terminal
Reassembly
24
14
13
10
11
22
4
3
25 2
18
16
15
17 26
12
5 23
27 9 21
28 6
29 7 19
30
8
1
20
WSLE0382
Name
1. Brush 16. Plate
2. Washer 17. Ball
3. Bearing 18. Armature
4. Front Bracket 19. Brush Holder
5. Gear Shaft 20. Yoke Assembly
6. Washer 21. Rear Bracket
7. Internal Gear 22. Through Bolt
8. Overrunning Clutch 23. Screw
9. E-shaped Retaining Ring 24. Magnetic Switch
10. Lever Spring 25. Screw
11. Lever 26. Lead Wire with Terminal
12. Planetary Gear 27. Pinion Spring
13. Plate 28. Pinion
14. Packing 29. Stop Ring
15. Packing 30. Snap Ring
1. Lubricant locations and tightening torque
N m (kg m / lb ft)
I
9.8 - 11.8 4.9 - 8.82
(1.0 - 1.2 / 7.2 - 8.7) (0.50 - 0.90 / 3.61 - 6.51)
C
B
H
2.35 - 4.41
(0.24 - 0.45 / 1.73 - 3.25)
G
F
E A D
7.84 - 12.74
(0.79 - 1.30 / 5.78 - 9.40)
WSLE0383
Lubricant locations
Shown in the Lubricant locations Lubricant agent
illustration
A Sleeve bearing and ball Molycote®AG650
B Clutch shaft sliding surface MULTEMP 6129
C Gear shaft spline section MULTEMP 0A-171
D Sliding portion of lever and overrunning clutch MULTEMP 6129
E Armature shift gear, planetary gear, internal gear Molycote®AG650
F Sliding portion of gear shaft MULTEMP 6129
G Outer surface of armature bearing (tiny amount) MULTEMP 6129
H Oil seal MULTEMP 6129
I Surface of plunger (tiny amount) MULTEMP 6129
2. Axial play of armature shift 5. Assembly of pinion
Adjustment is unnecessary (assemble the ball into Assemble the pinion spring, pinion and stop ring to
a tip of shaft.) clutch shaft in this order, then assemble the snap
3. Axial play of gear shaft ring to the groove of clutch shaft at the end.
Adjustment is unnecessary Then, pull strongly the stop ring toward the snap
Appropriate gap will be obtained automatically ring side with a gear puller and fix both of them.
when one washer (removed in step 12 of disas-
sembly procedure) is inserted between internal CAUTION:
gear and gearshift. • Assemble the pinion before assembling the
4. Assembly of gear shaft magnetic switch to front bracket.
Pass the gear shaft through washer, internal gear • Do not reuse the removed snap ring.
and overrunning clutch. Then move the overrun-
ning clutch by one tooth of spline to make sure that
the clutch cannot be pulled out. Assemble the E-
shaped retaining ring. 4
3
CAUTION:
2
• Do not reuse removed E-shaped retaining ring.
1 5
• If assembling the E-shaped retaining ring prior
to the overrunning clutch, the clutch cannot be
assembled. Be careful with it.
WSLE0384
Name
1. Pinion
4 2. Clutch Shaft
3. Snap Ring
5 4. Stop Ring
5. Pinion Spring
1 6. Check of the pinion protruded position

After assembling the starter, check the protruded
position of pinion.
WSHK0086
How to measure and adjust
Name
1. Overrunning Clutch • Connect the starter to battery.
2. Washer When closing the switches SW1 and SW2, the
3. Gear Shaft pinion move forward to the cranking position
4. E-shaped Retaining Ring and the armature rotates.
5. Internal Gear Then, open the switch SW2 to stop the arma-
ture rotating.
• Push into or pull back a tip of the clutch shaft
lightly by hand and measure the moving dis-
tance of it.
Adjust by using one or two packings (0.5 mm
{0.020 in}) between magnetic switch and front
bracket so that this measurement value is
between 0.5 — 2.0 mm {0.020 — 0.079 in}.
If this adjustment cannot be done, replace the
lever.
No Load Test
1. After adjusting the protruded position of pinion,
connect the starter as shown in the illustration
SW 1 B
above.
S
CAUTION:
M
Use a thick electric wire and tighten the connected
Battery portion securely.
SW 2
24V
2. Close the switch and read the speed, current and
Disconnect the lead wire voltage.
(attached with terminal)
from the M terminal.
If the measured values are out of specified value,
disassemble and inspect again.
Wiring diagram to move pinion forward
WSLE0378
2 A SW B
S
M
1 V 3
Amount of shaft moved
Push back the clutch

shaft lightly by hand.
WSHK0090
Name
Check of pinion moving out position 1. Battery 24 V
2. Ammeter
3. Voltmeter
WSHK0089
Maintenance Standard
Item Standard value or limit

No load characteristic Voltage V 23
Speed r/min 3,750 or more
Commutator Outside diameter mm/in 32/1.260
Limit mm/in 31.4/1.236
Commutator Undercut mm/in 0.5/0.020
Limit mm/in 0.2/0.008
Brush Length mm/in 17.5/0.689
Limit mm/in 11/0.433
Brush spring Pressure N 26.7 — 36.1
Limit N 14.7
Protruded position of pinion mm/in 0.5 — 2.0/0.020 — 0.079
4LE2 Exhaust System 1G-1
Engine
4LE2 Exhaust System
Table of Contents
EGR Control..........................................................1G-2
Appearance of EGR Controller ..........................1G-2
EGR Controller Wiring Diagram .........................1G-2
Connector Pin Layout.........................................1G-3
Engine Coolant Temperature Sensor Circuit Diagram
...........................................................................1G-3
Tachosensor Circuit Diagram.............................1G-3
Boost Pressure Sensor Circuit Diagram ............1G-4
Engine Coolant Temperature Control ................1G-4
Engine Speed and Boost Pressure Control .......1G-4
Control When the Sensor Has an Open Circuit .1G-5
Inspection...........................................................1G-5
1G-2 4LE2 Exhaust System
EGR Control
Appearance of EGR Controller EGR Controller Wiring Diagram
The harnesses between the EGR controller and EGR
cut solenoid are machine parts. Contact the machine
manufacturer if it is found to be faulty.
1
4 9
(9)
(8) 6 10 (1)
11
(7) 13
3 (2)
1 (10)
(6) (3)
2
5 7
WSLE0360
PC (5) (4)
Name 12 8
1. Connector
WSLE0361
Name
1. Boost Pressure Sensor
2. Glow Plug Timer
3. Engine Coolant Temperature Sensor
4. Tachometer
5. Tachosensor
6. Starter Switch
7. EGR Relay
8. Stop Relay
9. Ignition Switch
10. EGR Cut Controller
Connector Pin Layout Engine Coolant Temperature Sensor
Pins are numbered by the arrangement when viewing Circuit Diagram
the EGR cut controller from the wiring side.
(1)
5V
(2)
7 8 9 10 11 12 13
1 2 3 4 5 6
(3)
WSLE0364
WSLE0370 Name
Name 1. EGR Cut Controller
1. Starter Switch 2. Engine Coolant Temperature Sensor
2. EGR Cut Controller GND 3. Glow Plug Timer
3. Engine Coolant Temperature Sensor
4. Ignition Switch (+)
5. (TXD)
6. Stop Relay Tachosensor Circuit Diagram
7. Tachosensor(+)
8. Tachosensor(−) (1)
9. Boost Pressure Sensor Power Supply
10. Boost Pressure Sensor Signal
5V
11. Boost Pressure Sensor GND
12. (EXD)
13. EGR Relay 7 8
(2)
(3)
WSLE0362
Name
1. EGR Cut Controller
2. Tachosensor
3. Tachometer
Boost Pressure Sensor Circuit Diagram When the engine speed and boost pressure
increase
(1)
Vcc kPa
{psi}
9 10
Boost pressure
1 3 2
(2)
15
{2.2}
0 1400 1850 rpm

Engine speed
WSLE0363
Name WSLE0365
1. EGR Cut Controller Name

2. Boost Pressure Sensor 1. EGR Valve Closed
2. EGR Valve Open
3. Engine Speed and Boost Pressure Increase
Engine Coolant Temperature Control
The EGR valve is opened when the engine coolant When the engine speed and boost pressure
temperature becomes 60°C {140°F} or more, and is decrease
closed when 55°C {131°F} or less.
Engine Speed and Boost Pressure Control kPa

{psi}
kPa
Boost pressure
{psi}
1 2
1 3 2
15
{2.2}
Boost pressure
OFF
OFF OFF
ON ON
ON 4
{0.6}
4 0 1250 1820 rpm
{0.6} Engine speed
WSLE0366
Name
0 1250 1400 1820 1850 rpm
Engine speed 1. EGR Valve Closed
2. EGR Valve Open
WSLE0371 3. Engine Speed and Boost Pressure Decrease
Name
1. EGR Valve Closed
2. EGR Valve Open
Control When the Sensor Has an Open
Circuit
Close the EGR valve if the engine coolant temperature
sensor, tachosensor, or boost pressure sensor has an
open circuit.
Inspection
EGR valve check
1. Shine a light from the direction shown in the illus-
tration.
2. Replace the EGR cut solenoid and valve case
together if the light can be seen from the opposite
side. The EGR valve has been stuck at opened
position.
WSLE0372
4LE2 Lubrication System 1H-1
Engine
4LE2 Lubrication System
Table of Contents
Lubrication System................................................1H-2
Service Precautions ...........................................1H-2
Explanations on Functions and Operation .........1H-2
Function Check ..................................................1H-3
Oil Filter.................................................................1H-4
Removal .............................................................1H-4
Installation ..........................................................1H-4
Oil Pump ...............................................................1H-5
Components.......................................................1H-5
Inspection...........................................................1H-5
1H-2 4LE2 Lubrication System
Lubrication System
Service Precautions Explanations on Functions and Operation
• During each disassembly, remove the old gasket The lubrication system uses the filter element com-
adhering to each part and mating part completely bined with a full flow bypass, water-cooled oil cooler,
using a scraper at the location, where the fluid gas- and oil jet for piston cooling.
ket is to be used, clean the traces of oil, moisture
and dirt completely using a cloth, and apply the
specified new fluid gasket at each location.
• Avoid excessive or insufficient coating volume.
Note that seizure may occur in case of excessive
coating due to clogging of the oil gallery and oil jet,
and oil and water leakage may occur if the coating
is insufficient.
• Always, the start and end of the application should
be overlapped.
Lubricating system diagram
Valve opening pressure 98 kPa (14.2psi)
Oil filter Oil gallery
Oil cooler Turbocharger Main bearing Idle gear bush Cylinder head
Valve
opening
pressure Rocker arm
Crankshaft Timing gear
539kPa (78.2psi) bracket
Connecting rod Governor Rocker shaft
Rocker arm
Oil pump Injection pump
Valve stem
Strainer Piston Tappet
end
Piston
pin boss
Oil pan
Pressure feeding Non pressure feeding

WSLE0170
Function Check
Engine oil
• Ensure the engine is at a level ground. Before
starting the engine or when 5 minutes or more
have elapsed after stopping the engine, check the
engine oil volume using the level gauge. The vol-
ume is appropriate if the engine oil is between the
upper and lower limits of the level gauge. Replen-
ish the engine oil, if level is below the lower limit.
Also, check for contamination of the engine oil.
WSLE0325
Name
1. Max.
2. Min.
Engine oil leakage

• In the lift up condition, confirm that there are no
leaks from the cylinder head cover and oil pan.
Oil Filter
Removal
Remove the oil filter using the oil filter wrench.
WSLE0375
Installation
Install the oil filter using the oil filter wrench.
Tightening torque:
14.7 — 20.6 N⋅m {1.5 — 2.1 kgf⋅m/10.8 — 15.2 lb⋅ft}
Oil Pump
Components
5
4
3
1 2 8
9
10
WSLE0171
Name
1. Pump Gear 6. Pin
2. Pump Cover 7. Oil Pump Body
3. O-ring 8. Relief Valve
4. Inner Rotor 9. Spring
5. Outer Rotor 10. Plug
Inspection Inspection of tip clearance between the inner

Replace or repair if there is wear, damage, or any other rotor and the outer rotor
defect on the rotor, etc. Use a thickness gauge to measure the tip clearance
between the inner rotor and the outer rotor, and replace
Inspection of clearance between the outer or the inner or outer rotor if it exceeds the limit.
inner rotor and the pump cover
mm {in}
Use a thickness gauge and square to measure the
clearance between the outer or inner rotor and the Standard value Service limit Repairing procedure
pump cover, and replace the outer or inner rotor if they 0.17 {0.0067} or 0.2 {0.008} Replace.
exceed the limit. less
mm {in}
0.040 — 0.085 0.15 {0.006} Replace.
{0.0016 — 0.0033}
Inspection of clearance between the outer

circle of the outer rotor and the pump body
Use a thickness gauge to measure the clearance
between the outer rotor and the oil pump body, and
replace the outer rotor if they exceed the limit.
mm {in}
0.100 — 0.185 0.4 {0.016} Replace.
{0.0039 — 0.0073}
4LE2 Intake System 1J-1
Engine
4LE2 Intake System
Table of Contents
Turbocharger..........................................................1J-2
Table of Specifications ........................................1J-2
Structure..............................................................1J-3
Disassembly........................................................1J-4
Inspection............................................................1J-7
Reassembly ......................................................1J-10
List of Measurement Tool..................................1J-15
List of Other Material.........................................1J-15
1J-2 4LE2 Intake System
Turbocharger
Table of Specifications
Item Assembly specification Service limit

Turbine shaft Axial play mm {in} 0.06 — 0.09 0.011 {0.000433}
{0.00236 — 0.00354}
Radial play mm {in} 0.10 — 0.17 0.205 {0.00807}
{0.00394 — 0.00669}
Journal outside diameter (A) mm {in} — 11.380 {0.44803}
Seal ring groove width (E) mm {in} — 1.33 {0.05236}
Runout mm {in} — 0.011 {0.00043}
Seal ring insertion Turbine side (bearing housing) (F) mm {in} — 17.03 {0.67047}
part
Compressor side (seal plate) (H) mm {in} — 14.05 {0.55315}
Oil thrower Seal ring groove width (G) mm {in} — 1.52 {0.05984}
Bearing Bearing housing inside diameter (B) mm {in} — 16.11 {0.63425}
housing
Thrust bearing inside diameter for (L) mm {in} — 23.020 {0.90630}
press-fit portion
Thrust bearing Bearing pad height at compressor side (J) mm {in} — 0.0 — 0.060 {0.0 —
0.00236}
Thrust collar thickness (K) mm {in} — 2.950 {0.11614}
H
F L
B A
K
E G
WSHK0126
Structure
4 5
2 3
10 9
1 8
WSHK0127
Name
1. Turbine Housing 6. Seal Plate
2. Heat Protector 7. Compressor Impeller
3. Floating Metal 8. Seal Ring
4. Oil Thrower 9. Seal Ring
5. Compressor Housing 10. Turbine Shaft
Disassembly
Disassembly diagram: disassemble in the order of the numbers.
4 2
3
6
5
13
14
17
16
16
15
8
18
7
11
12
10
9
WSHK0128
Name
1. Compressor Housing 10. Seal Ring
2. Nut 11. Gasket
3. Compressor Impeller 12. Heat Protector
4. Seal Plate 13. Thrust Bearing
5. Oil Thrower 14. Thrust Collar
6. Seal Ring 15. Snap Ring
7. G Coupling 16. Floating Metal
8. Turbine Housing 17. Thrust Bearing
9. Turbine Shaft 18. Bearing Housing
CAUTION:
If you perform inspection with the turbocharger removed from the engine, plug the oil port opening before
work.
Inspection prior to disassembly • Measurement on the machine of radial play of tur-
bine shaft
• Measurement of axial play of turbine shaft
Insert a thickness gauge into the gap between the
Axial play mm {in} compressor impeller and housing, and measure
the clearance.
Assembly specification 0.06 — 0.09 {0.0024 — 0.0035}
The thickness gauge to be inserted must be 0.2
Service limit 0.11 {0.0043} mm {0.0078 in} or less.
1. Compressor housing
If it exceeds the service limit, check the thrust • Put alignment marks between the compressor
metal, the thrust bushing, and the oil thrower. housing and the seal plate, and tap the com-
pressor housing to drive it out.
• Liquid gasket is applied to the mating surface of
the compressor housing and the seal plate.
CAUTION:
Take care not to damage the impeller during
removal of the compressor housing.
WSHK0129
• Measurement of radial play of turbine shaft
1
Radial play mm {in}
Assembly specifi- 0.10 — 0.17 {0.00394 — 0.00669}
cation
Service limit 0.205 {0.00807}
WSHK0131
If it exceeds the service limit, check the floating Name
metal. 1. Alignment Mark
WSHK0130
2. Compressor impeller 4. Oil thrower
• Attach the box spanner to the turbine-side shaft • Remove the oil thrower from the seal plate.
end of the turbine shaft, and remove the nut. 5. G coupling
(The nut is left-hand screw.)
• Loosen the nut and remove the G coupling from
• Remove the impeller from the turbine shaft. the turbine housing and the center housing.
• Washing of impeller 6. Turbine housing
Soak in the cleaning solvent until the foreign
• Remove the turbine housing from the center
matters soften, and clean it with a plastic
housing.
scraper or hard brush.
• Washing of turbine housing
CAUTION: Soak in the cleaning solvent to remove the for-
Do not use a wire brush. eign matters.
WSHK0134
WSHK0132 7. Turbine shaft
Name • Hold the heat protector lightly by hand, and
1. Left-hand Thread take out the turbine shaft.
3. Seal plate • If it is hard to remove, lightly tap the compres-
sor-side shaft end with a wooden hammer.
• Loosen the pot small screw.
• Washing of turbine shaft
• Lightly tap the bearing housing in the seal plate Soak in the cleaning solvent until the foreign
with a wooden hammer. matters soften, and clean it with a plastic
• Liquid gasket is applied to the mating surfaces scraper or hard brush.
of the seal plate and the bearing housing.
CAUTION:
• Do not use a wire brush.
• Foreign matters remaining on the surface
causes the unbalance of weight. Therefore,
wash it thoroughly.
• Take care not to damage the floating metal con-
tact surface of the shaft and the seal ring
groove.
WSHK0133
Inspection
Compressor housing
• Check the compressor housing for crack or dam-
age, and replace if defective.
WSHK0135
8. Heat protector
• Remove the heat protector from the bearing
housing.
9. Thrust bearing (compressor side) WSHK0136
• Loosen the plate small screw with a screw-
driver, and remove the thrust bearing and the Turbine housing
thrust collar. • Check the turbine housing for crack or damage,
10. Floating metal and replace if defective.
• Remove the turbine-side snap ring with snap
ring pliers. Impeller
• Draw out the floating metal from the bearing • Check the impeller for scratch, dent or crack.
housing.
11. Thrust bearing (turbine side)
• Using a brass bar, push out the compressor-
side floating metal from the turbine-side bearing
housing, together with the thrust bearing.
CAUTION:
While pushing out with a bar, take care that they do
not run on to damage the snap ring.
12. Snap ring

• Remove the two snap rings from the bearing
housing with snap ring pliers.
13. Seal ring
• Remove the seal ring from the turbine shaft and
the oil thrower.
WSHK0137
Heat protector • Measurement of turbine shaft runout
• Check the heat protector for damage, thermal Turbine shaft runout mm {in}
deformation or corrosion.
WSHK0138
Turbine shaft WSHK0140

• Measure the journal outside diameter of the tur-
bine shaft, and the groove width of the seal ring Seal plate
insertion part. • Inspection of damage on the seal plate, measure-
ment of inside diameter of the seal ring insertion
Journal outside diameter mm {in} part
Service limit φ 11.38 {0.4480}
Inside diameter of the seal mm {in}
ring insertion part
Groove width of the seal ring mm {in} Service limit
insertion part
H 14.05 {0.5531}
WSHK0141
WSHK0139
Name
1. Journal Outside Diameter
2. Ring Groove Width
Oil thrower Bearing housing
• Inspection of damage on the oil thrower sliding sur- • Check the casting surface for peeling from oxida-
face, measurement of the seal ring groove width tion-deterioration, dent or crack. Replace with new
one if faulty.
Seal ring groove width G mm {in}
mm {in}
Service limit
Location Service limit
G 1.52 {0.0598}
Bearing housing inside diameter (B) 16.11
Thrust collar {0.6343}
• Measure the thrust collar thickness (K), and Turbine-side seal ring insertion part (F) 17.03
{0.6705}
replace with new one if it exceeds the service limit.
Turbine-side thrust bearing press-fit (L) 23.02
Thrust collar thickness mm {in} portion inside diameter {0.9063}
Service limit
K 2.950 {0.11614}
G
F B L
WSHK0143
G coupling
WSHK0142
• Replace with new one.
Thrust bearing
Seal ring
• Replace the compressor-side and the turbine-side
thrust bearings with new ones. • Replace with new one.
Floating metal Others

• Replace the floating metal with new one. • Check the bolts for deformation, and replace with
new ones if faulty. Also, replace the plate small
screw with new one.
Reassembly
Assembly diagram: Assemble in the order of the numbers.
18
15 17
16
13
14
9
8
4
3
3
11
1
12
10
6
5
7
WSHK0144
Name
1. Bearing Housing 10. Gasket
2. Snap Ring 11. Turbine Housing
3. Floating Metal 12. G Coupling
4. Thrust Bearing 13. Seal Ring
5. Seal Ring 14. Oil Thrower
6. Heat Protector 15. Seal Plate
7. Turbine Shaft 16. Compressor Impeller
8. Thrust Collar 17. Nut
9. Thrust Bearing 18. Compressor Housing
1. Bearing housing
• Check that the bearing housing is free of dam-
age and foreign matters.
2. Snap ring
• Install the two snap rings to the bearing housing
with snap ring pliers.
• After assembling the floating metal (turbine
side), install the snap ring at the position shown
in the figure.
1
WSHK0146
Name
1. Apply Oil.
4. Thrust bearing
1 a. Press-fitting of turbine-side thrust bearing
• Press-fit the turbine-side thrust bearing into
the bearing housing.
• Position the pawl of the turbine-side thrust
WSHK0145 bearing for more than 2 mm {0.0787 in}
Name apart from the existing press-fitting part.
1. Turbine-side Floating Metal • Do not press the thrust bearing pad surface
during press-fitting.
3. Floating metal • The press-fit pressure must be between
• Apply oil to the floating metal, and assemble it 215.6 N {22.0 kgf} and 1,862 N {190 kgf}.
to the bearing housing. • After press-fitting, remove the dust powder
After securing it with a snap ring, assemble the by vacuum.
compressor-side floating metal.
CAUTION:
• Place the snap ring with its rounded-side facing
to the floating metal.
• Assemble the inner snap ring with its end gap
facing to the oil outlet-direction of the housing,
to prevent it from blocking the oil passage.
• Assemble the turbine-side snap ring to the
housing with its end gap facing to the direction
as shown in the illustration.
• Apply oil to the floating metal before assembly.
Besco super engine oil
b. After press-fitting, check the depth and flatness
of the turbine-side thrust bearing.
(Depth 3.08±0.02 mm {0.1213±0.0008 in}, Flat-
ness is below 0.01 mm {0.0004 in}: See illustra-
tion)
mm(in)
1
3.08 0.02
(0.1213 0.0008)
1
0
12
WSHK0149
Name
120 1. Apply Oil.
8. Thrust collar
WSHK0147
• Apply engine oil to the thrust collar, and install it
Name to the turbine shaft.
1. Common Tolerance 9. Thrust bearing
5. Seal ring • Apply engine oil to the metal portion of the
thrust bearing, and insert it to the bearing hous-
• Insert the seal ring to the turbine shaft.
ing.
• Use new seal ring.
• Apply Loctite to the plate small screw threads,
6. Heat protector and install it using torque screwdriver.
• Install the heat protector to the bearing housing.
Tightening torque:
7. Turbine shaft 3.7 N⋅m {0.38 kg⋅m/33 lb⋅in}
• Apply engine oil to the journal portion of the tur-
bine shaft, and insert it from the turbine side of
the bearing housing.
• Take care not to damage the floating metal with
the turbine shaft. Also, insert with the end gap
of the seal ring facing to the oil inlet side so that
its core matches with the turbine shaft.
WSHK0150
Name
1. Apply Oil.
10. Gasket
• Set the gasket to the turbine housing, and
install it to the bearing housing.
11. Turbine housing
• Assemble by aligning the phase of the turbine
housing and the bearing housing with the tur-
bine housing positioning pin and the bearing (2)
housing hole.
(1) A (3)
1 2
(4) (6)
(5)
WSHK0152
Name
1. Approx. 60°
2. Approx. 60°
3. Torque Wrench
WSHK0151
Hammering procedure
12. G coupling
1. Using a metal hammer (Approx. 250 g in
a. Check that it does not run on the turbine hous- weight), lightly tap 2 to 3 times (same place),
ing or the bearing housing. from the outer portion toward the center.
b. Tighten temporarily to the specified torque 2. Do not hammer the G coupling directly. Place
using a torque wrench. brass bar between as shown in the illustration.
Tightening torque:
83 N⋅m {8.5 kg⋅m/61 lb⋅ft}
c. Hammering: Perform the hammering of (1) to
(6) in the numerical order, using the following
procedure.
d. Tighten to the specified torque using a torque
wrench. 150 ~ 200 mm
2 (6 ~ 8 in) 3 4
Tightening torque:
83 N⋅m {8.5 kg⋅m/61 lb⋅ft} 5
e. Perform (c) and (d) of the above step again.

1
7 6
WSHK0153
Name
1. Approx. φ 13 mm {0.5 in}
2. Hammer
3. G Coupling
4. Bearing Housing
5. Gasket
6. Heat Shield Plate
7. Turbine Housing
13. Seal ring 18. Compressor housing
• Install the seal ring to the oil thrower. • Apply liquid gasket to the compressor-side
• Use new one. flange surface of the seal plate. Illustration
shown in Step 15 (A)
14. Oil thrower
Application thickness 0.1 — 0.2 mm {0.004 —
• Insert the oil thrower into the seal plate. 0.008 in}
• Insert with the end gap of the seal ring facing to
the oil inlet side. ThreeBond No.1207
15. Seal plate
• Align the alignment marks that marked during
• Apply liquid gasket to the turbine-side flange
the disassembly, and assemble the compressor
surface.
housing to the seal plate.
Application thickness 0.1 — 0.2 mm {0.004 —
0.008 in} (B) Tightening torque:
7.9 N⋅m {0.81 kg⋅m/70 lb⋅in}
ThreeBond No.1207
• Install the seal plate to the bearing housing.

• Apply Loctite (B) to the pot small screw threads,
and install it using torque screwdriver.
Tightening torque:
23 N⋅m {2.3 kg⋅m/17 lb⋅ft}
B
A
WSHK0156
Check after assembly

• Make sure that the axial play and radial play of
rotor are within the specified value.
Refer to 1J-7, “Inspection, Turbocharger”.
WSHK0154
16. Compressor impeller

• Insert the compressor impeller to the turbine
shaft.
17. Nut
• Attach the box spanner to the turbine-side shaft
end of the turbine shaft, and tighten the nut.
• The nut is left-hand thread. Make sure the turn-
ing direction.
Tightening torque:
7.8 N⋅m {0.80 kg⋅m/69 lb⋅in}
List of Measurement Tool
Shape Name Part number Usage

Caliper — Measurement of the seal ring groove width
Measurement of inside diameter of the seal ring inser-
tion part
Measurement of turbine shaft journal outside diame-
ter
Measurement of thrust bushing groove clearance
Measurement of thrust bearing thickness
Measurement of floating metal inside/outside diame-
WSHK0157 ter
Measurement of inside diameters of the center hous-
ing metal portion and ring portion
Dial gauge — Measurement of turbine shaft axial gap, radial gap
and runout
WSHK0158
List of Other Material
Name Usage
Besco super engine oil Floating metal sliding portion
Thrust bushing sliding portion
Thrust bearing sliding portion
Turbine shaft journal portion
ThreeBond No.1207 Housing installation surface of the seal plate
Flange of the compressor housing
Loctite No.242 Seal plate tightening screw thread
4LE2 Preheating System 1K-1
Engine
4LE2 Preheating System
Table of Contents
Preheating System................................................ 1K-2
Explanations on Functions and Operation ......... 1K-2
Glow Plug Check................................................ 1K-2
List of Trouble Symptom .................................... 1K-2
1K-2 4LE2 Preheating System
Preheating System
Explanations on Functions and Operation
The preheating system consists of the glow plug timer,
the glow plugs and the glow indicator lamp. The pre-
heating system is operated when the engine coolant
temperature is low, and makes the engine easy to start.
Glow Plug Check

• Use the circuit tester and measure the resistance
of the glow plug.
• If the measured value deviates from the specified
value, then replace the glow plug.
Resistance value of glow plug is 3Ω.
Note:
Use a set of glow plug from the same manufacturer.
Condition Possible cause Correction

The glow indicator lamp does not light up. Slow-blow fuse has blown. Replace the slow-blow fuse.
Fuse is unavailable. Replace the fuse.
Indicator bulb is burnt out. Replace the indicator bulb.
Preheating does not work. Slow-blow fuse has blown. Replace the slow-blow fuse.
Defective or faulty glow plug relay Re-mount or replace the glow
connector contact. plug relay.
Preheating time is too long or too short. Thermo-sensor fault and break in Replace the thermo-sensor.
circuit or short circuit. Repair the circuit.
Fault in glow plug. Replace or tighten the glow plug.

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HYDRAULIC EXCAVATOR

Book Code No.S5YT0015E01

2) WARNING- Indicates a potentially hazardous

The proper and safe lubrication and maintenance

2010-10 & ASSEMBLING

YT06-18444~ APPLICABLE MACHINES

1.1 GENERAL PRECAUTIONS FOR MAKING REPAIRS ……………………………………………………1-3

Book Code No. S5YN0129E01

Issue Date of Issue Applicable Machines Remarks

August, 2009 SK80MSR-2 : LF06-04501~

November, 2009 SK850LC : LY02-00151~

June, 2010 SK80CS-2 : LF06-04501~

July, 2010 E135BSRLC : YH06-08001~

September, 2010 E385CLC : YC

October, 2010 SK80MSR-2 : LF06-04547~

1.1 GENERAL PRECAUTIONS FOR MAKING REPAIRS

(1) Knowledge of operating procedure

(2) Cleaning machines

(3) Inspecting machines

1. Inspecting date, place

(5) Arrangement and cleaning in service shop

1.1.2 SAFETY WHEN DISASSEMBLING AND ASSEMBLING

1.1.3 DISASSEMBLING AND ASSEMBLING HYDRAULIC EQUIPMENT

(1) Removing hydraulic equipment assy

(2) Disassembling hydraulic equipment

(3) Inspecting parts

(4) Reassembling hydraulic equipment

(5) Installing hydraulic equipment

For cylinder, don't move it to the stroke end at beginning.

1.1.4 ELECTRICAL EQUIPMENT

(1) The disassembly of electrical equipment is not allowed.

Battery fluid is dangerous.

1.1.5 HYDRAULIC PARTS

(2) Flexible hose (F hose)

1.1.6 WELD REPAIR

1.1.7 ENVIRONMENTAL ISSUES

1.2 INTERNATIONAL UNIT SYSTEM

2.1 NAME OF COMPONENTS ……………………………………………………………………………………2-3

Book Code No. S5YT0215E01

Issue Date of Issue Applicable Machines Remarks

2.1 NAME OF COMPONENTS

2.2 GENERAL DIMENSIONS

2.2.1 1.71m (5ft-7in) ARM + 0.28m3 (0.37cu-yd) BUCKET

Dimensions marked * do not include the height of the shoe lug.

2.3 WEIGHT OF COMPONENTS

Numerical values marked * indicate the dry weight.

2.4.1 OVERALL DIMENSIONS OF MACHINE ON A TRUCK

2.4.2 DIMENSIONS OF ATTACHMENT

(2) ARM AND BUCKET

2.5 SPECIFICATIONS AND PERFORMANCE

2.5.1 SPEED AND CLIMBING CAPABILITY

Item / Model SK70SR-2

Engine model ISUZU AU-4LE2X

2.5.3 HYDRAULIC COMPONENTS

Hydraulic pump Variable displacement axial piston + gear pump

2.6 TYPE OF CRAWLER

2.7 TYPE OF BUCKET

2.8 COMBINATIONS OF ATTACHMENT

2.9 ENGINE SPECIFICATION

Applicable machine SK70SR-2