HD 785 - 5LC CEBD013800 Shop Manual PDF
HD 785 - 5LC CEBD013800 Shop Manual PDF
HD 785 - 5LC CEBD013800 Shop Manual PDF
Shop
Manual
LC
DUMP TRUCK
®
NOTES:
Unsafe use of this machine may cause serious injury or death. Operators and maintenance
personnel must read and understand this manual before operating or maintaining this machine.
This manual should be kept in or near the machine for reference, and periodically reviewed by
all personnel who will come into contact with it.
This material is proprietary to Komatsu America Corp (KAC), and is not to be reproduced, used, or
disclosed except in accordance with written authorization from KAC.
It is the policy of the Company to improve products whenever it is possible and practical to do so. The
Company reserves the right to make changes or add improvements at any time without incurring any
obligation to install such changes on products sold previously.
Because of continuous research and development, periodic revisions may be made to this publication.
Customers should contact their local Komatsu distributor for information on the latest revision.
CALIFORNIA
Proposition 65 Warning
Diesel engine exhaust, some of its constituents, and certain vehicle
components contain or emit chemicals known to the State of California to
cause cancer, birth defects or other reproductive harm.
CALIFORNIA
Proposition 65 Warning
Battery posts, terminals and related accessories contain lead and lead
compounds, chemicals known to the State of California to cause cancer
and birth defects or other reproductive harm. Wash hands after handling.
NOTES
FOREWORD
This manual is written for use by the service technician and is designed to help the technician become fully knowl-
edgeable of the truck and all its systems in order to keep it running and in production. All maintenance personnel
should read and understand the materials in this manual before performing maintenance and/or operational checks
on the truck. All safety notices, warnings and cautions should be understood and followed when performing repairs
on the truck.
The first section covers component descriptions, truck specifications and safe work practices, as well as other gen-
eral information. The major portion of the manual pertains to disassembly, service and reassembly. Each major
serviceable area is dealt with individually. For example: The disassembly, service and reassembly of the radiator
group is discussed as a unit. The same is true of the engine and engine accessories, and so on through the entire
mechanical detail of the truck. Disassembly should be carried only as far as necessary to accomplish needed
repairs.
The illustrations used in this manual are, at times, typical of the component shown and may not necessarily depict
a specific model.
This manual shows dimensioning of U.S. standard and metric (SI) units throughout, and all references to "Right",
"Left", "Front", or "Rear" are made with respect to the operator's normal seated position, unless specifically stated
otherwise.
Standard torque requirements are shown in torque charts in the general information section and individual torques
are provided in the text in bold face type, such as 100 ft.lbs. (135 N.m) torque. All torque specifications have ±
10% tolerance unless otherwise specified.
A Product Identification plate is normally located on the truck frame upright in front of the left side front wheel and
designates the Truck Model Number, Product Identification Number (vehicle serial number), and Maximum G.V.W.
(Gross Vehicle Weight) rating.
The Product Identification Number (vehicle serial number) contains information which will identify the original man-
ufacturing bill of material for this unit. This complete number will be necessary for proper ordering of many service
parts and/or warranty consideration.
The Gross Vehicle Weight (GVW) is what determines the load on the drivetrain, frame, tires, and other compo-
nents. The vehicle design and application guidelines are sensitive to the total maximum Gross Vehicle Weight
(GVW) and this means the total weight: the Empty Vehicle Weight + the fuel & lubricants + the payload.
To determine allowable payload: Ensure the dump body is empty, all lubricants (including fuel) are at the proper
level. All accessories that will be used (body liners, tailgates, etc.) should be in place on the truck. When the truck
is in its operating condition, it can now be weighed. Record this value and subtract from the GVW rating. The
remainder is the allowable payload.
NOTE: Accumulations of mud, frozen material, etc. become a part of the GVW and reduces allowable payload. To
maximize payload and to keep from exceeding the GVW rating, these accumulations should be removed as often
as practical.
!CAUTION! Exceeding the allowable payload will reduce expected life of truck components.
SUBJECT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .SECTION
GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A
STRUCTURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B
ENGINE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C
ELECTRICAL SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D
TRANSMISSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F
SUSPENSIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . H
BRAKE CIRCUIT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . J
AIR SYSTEM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . K
HYDRAULIC SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . L
OPERATOR'S CAB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . N
ALPHABETICAL INDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Q
SYSTEM SCHEMATICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . R
GENERAL INFORMATION
INDEX
TRANSMISSION
The TORQFLOW transmission assembly consists of BRAKE SYSTEM
a 3-element, single-stage, two-phase torque con-
Depressing the brake pedal actuates front and rear
verter driving a planetary gear, hydraulically-actuated
air-over-hydraulic service brakes. The front service
multiple disc clutch transmission which is force-lubri-
brakes are caliper disc type. The rear service brakes
cated for optimum heat dissipation.
are oil-cooled, multiple-disc brakes (acts also as
The TORQFLOW transmission is capable of seven retarder).
(7) forward speeds and one (1) reverse gear. Auto-
matic shifting is controlled by electronic shift control
with automatic clutch modulation in all gears.
A lockup system consisting of a wet, double-disc
clutch, is activated in F1-F7 gears for increased fuel
savings. RETARDER
The operator can manually apply the rear oil-cooled,
multiple-disc retarder brakes by moving the retarder
control lever which is mounted on the steering col-
umn. These brakes are automatically activated when
FINAL DRIVE ASSEMBLY the engine speed exceeds the rated revolutions of
The final drive consists of a plug-in differential with the shift position.
planetary wheel drives.
Read and follow all safety precautions. Failure to do so may result in serious injury or
death.
Safety Rules
• ONLY trained and authorized personnel can operate and maintain the machine.
• Follow all safety rules, precautions and instructions when operating or performing maintenance on the
machine.
• When working with another operator or a person on work site traffic duty, be sure all personnel understand all
hand signals that are to be used.
Safety Features
• Be sure all guards and covers are in their proper position. Have guards and covers repaired if damaged. (See
Walk-Around Inspection, Operating Instructions - Section 3)
• Learn the proper use of safety features such as safety locks, safety pins, and seat belts, and use these safety
features properly.
• NEVER remove any safety features. ALWAYS keep them in good operating condition.
• Improper use of safety features could result in serious bodily injury or death.
Unauthorized Modification
• Any modification made to this vehicle without authorization from Komatsu America Corp. can possibly create
hazards.
• Before making any modification, consult the authorized regional Komatsu America Corp. distributor. Komatsu
will not be responsible for any injury or damage caused by any unauthorized modification.
Safety At Worksite
• When walking to and from the truck, maintain a safe distance from all machines even if the operator is visible.
• Before starting the engine, thoroughly check the area for any unusual conditions that could be dangerous.
• Examine the road surface in the job site and determine the best and safest method of operation.
• Choose an area where the ground is as horizontal and firm as possible before carrying out the operation.
• If you need to operate on a road, protect pedestrians and cars by designating a person for work site traffic duty
or by installing fences around the work site.
• The operator must check personally the work position, roads to be used, and existence of obstacles before
starting operations.
• Always determine the travel roads in the work site and maintain them so that it is always safe for the machines
to travel.
• If travel through wet areas is necessary, check the depth and flow of water before crossing the shallow parts.
NEVER be in water which is in excess of the permissible water depth.
Fire Prevention
• Thoroughly remove wood chips, leaves, paper and other flammable things
accumulated in the engine compartment. These could cause a fire.
• Check fuel, lubrication, and hydraulic systems for leaks. Have any leaks
repaired. Wipe up any excess oil, fuel or other flammable fluids.
• Be sure a fire extinguisher is present and working.
• Do not operate the machine near any flame.
In Operator's Cab
• Do not leave tools or spare parts lying around in the operator's compartment. They may damage or break the
control levers or switches. Always put them in the tool box on the right side of the machine.
• Keep the cab floor, controls, steps and handrails free of oil, grease, snow, and excess dirt.
• Check the seat belt, buckle and hardware for damage or wear. Replace any worn or damaged parts. Always
use seat belts when operating your machine.
• Check for flat tires periodically during shift. If truck has been run on a “flat”, it must not be parked in a
building until the tire cools. If tire must be changed, do not stand in front of rim and locking ring when
inflating tire mounted on the machine. Observers should not be permitted in the area and should be kept away
from the side of such tires.
Tire and rim assembly may explode if subjected to excessive heat. Personnel should move to a remote or
protected location if sensing excessively hot brakes, smell of burning rubber or evidence of fire near tire
and wheel area.
If the truck must be approached, such as to fight a fire, those personnel should do so only while facing the
tread area of the tire (front or back), unless protected by use of large heavy equipment as a shield. Stay at
least 50 ft. (15 m) from the tread of the tire.
In the event of fire in the tire and wheel area (including brake fires), stay away from the truck at least 8
hours or until the tire and wheel are cool.
• Keep serviceable fire fighting equipment at hand. Report used extinguishers for replacement or refilling.
• Always have parking brake applied when the truck is parked and unattended. DO NOT leave truck unattended
while engine is running.
• When parking, park a safe distance from other vehicles as determined by supervisor.
• Stay alert at all times! In the event of an emergency, be prepared to react quickly and avoid accidents. If an
emergency arises, know where to get prompt assistance.
Traveling
• When traveling on rough ground, travel at low speed. When changing direction, avoid turning suddenly.
• Lower the dump body and set the dump lever to the FLOAT position when traveling.
• If the engine should stop when the machine is traveling, the emergency steering system will be activated.
Apply the brakes immediately and stop the machine as quickly and safely as possible, and off the haul road, if
possible.
When Loading
• Check that the surrounding area is safe, stop the machine in the correct loading position, then load the body
uniformly.
• Do not leave the operator's seat during the loading operation.
TOWING
When Towing, Attach Cable To Hook
• Towing in the wrong way may lead to serious personal injury or damage.
• When using another machine to tow this machine, use a towing device with ample strength for the weight of
this machine.
• Never tow a machine on a slope.
• Do not use any towing rope that has kinks or is twisted.
• Do not stand astride the towing cable or wire rope.
• When connecting a machine that is to be towed, do not let any one come between the towing machine and the
machine that is being towed.
• Set the coupling of the machine being towed in a straight line with the towing portion of the machine, and
secure it in position.
(For towing method, see Operating Instructions, TOWING.)
Proper Tools
• Use only tools suited to the task. Using damaged, low quality, faulty, or makeshift tools
could cause personal injury.
Always store pin in body storage hole. Placement of the pin in mainframe or matching body-up holes
located on the body can cause damage to frame or body during dumping cycle.
Never work under a raised body unless body safety pin is in the proper position to hold body up.
DURING MAINTENANCE
Personnel
• Only authorized personnel can service and repair the machine. Extra precaution should be used when
grinding, welding, and using a sledge-hammer.
Attachments
• Place attachments that have been removed from the machine in a safe place so
that they do not fall. If they fall on you or others, serious injury could result.
Use Of Lighting
When checking fuel, oil, coolant, or battery electrolyte, always use lighting
with anti-explosion specifications. If such lighting equipment is not used,
there is danger or explosion.
• Immediately after stopping operations, the engine cooling water and oil at
all parts are at high temperature and under high pressure.In this condition, if
the cap is removed, or the oil or water are drained, or the filters are
replaced, it may result in burns or other injury. Wait for the temperature to
go down, then carry out the inspection and maintenance in accordance with
the procedures given in this manual.
Waste Materials
• Never dump waste oil in a sewer system, rivers, etc.
• Always put oil drained from your machine in containers. Never drain oil
directly on the ground.
• Obey appropriate laws and regulations when disposing of harmful objects
such as oil, fuel, coolant, solvent, filters, batteries, and others.
This warning plate is located inside the cab on the left-hand door panel under the arm rest. It contains (3) instruc-
tions - Preparation for Operation, Precautions Prior to Moving Truck, and Hoist Control Lever operation. These
decals stress the importance of reading and understanding the operators manual prior to the operation of equip-
ment.
This CAUTION plate is located on left hand side of A plate is located next to filler cap on fuel cap which
the radiator shroud. Extreme care should be taken specifies Diesel Fuel Only. Care should be taken to
when working around fan and belts. Hands and loose open cap slowly and bleed off pressure that may be
articles of clothing should be kept away when in tank when removing filler cap.Operation and Main-
machine is operating. tenance Manual referred to is from Engine Manufac-
turer.
A product identification plate (below) is located at the lower back side of the left-hand upright structure. This plate
lists the vehicle model number and Product Identification Number. The Product Identification Number contains
information which will identify the original manufacturing bill of material for this unit. This complete number will be
necessary for the proper ordering of many service parts and/or warranty consideration.
.
A plate attached to the left rear of the optional FOPS structure, over the cab states the Rollover Protective Struc-
ture and Falling Object Protective Structure meets various SAE performance requirements.
Do not make modifications to the FOPS structure or attempt to repair damage without written approval of
the manufacturer. Unauthorized repairs will void certification.
This manual provides dual dimensioning for many specifications. Metric units are specified first, with U.S. standard
units in parentheses. References throughout the manual to standard torques or other standard values will be to
one of the following Tables.
For values not shown in any of the charts or tables, standard conversion factors for most commonly used measure-
ments are provided in the conversion table below.
INDEX OF TABLES
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page
TABLE I STANDARD TIGHTENING TORQUE COMMON CONVERSION MULTIPLIERS
METRIC To ENGLISH
. . . . . . . . . . . . . . . . For Capscrews and Nuts A5-2
Multiply
To Convert From TO By
millimeter (mm) inch – in. 0.0394
TABLE II STANDARD TIGHTENING TORQUE
centimeter (cm) inch – in. 0.3937
. . . . . . . . . . . . . . . . . . For Split Flange Bolts A5-2
meter (m) foot – ft. 3.2808
meter (m) yard – yd. 1.0936
TABLE III . . . . . .TIGHTENING TORQUE FOR kilometer (km) mile – mi. 0.6210
2 2 0.1550
sq. centimeters (cm ) sq. in. – in.
. . . . . . . . . . . Flared Tube And Hose Fittings A5-2
sq. centimeters (cm2) sq. ft. – ft.2 0.001
0 (kPa) 6.895 13.79 20.68 27.58 34.47 41.37 48.26 55.16 62.05
10 68.95 75.84 82.74 89.63 96.53 103.42 110.32 117.21 124.1 131.0
20 137.9 144.8 151.7 158.6 165.5 172.4 179.3 186.2 193.1 200.0
30 206.8 213.7 220.6 227.5 234.4 241.3 248.2 255.1 262.0 268.9
40 275.8 282.7 289.6 296.5 303.4 310.3 317.2 324.1 331.0 337.9
50 344.7 351.6 358.5 365.4 372.3 379.2 386.1 393.0 399.9 406.8
60 413.7 420.6 427.5 434.4 441.3 448.2 455.1 462.0 468.9 475.8
70 482.6 489.5 496.4 503.3 510.2 517.1 524.0 530.9 537.8 544.7
80 551.6 558.5 565.4 572.3 579.2 586.1 593.0 599.9 606.8 613.7
90 620.5 627.4 634.3 641.2 648.1 655.0 661.9 668.8 675.7 682.6
NOTE: Tables such as Table V, VI, VII, VIII, and IX may be used as in the following example:
Example: Convert 955 kg.m to foot pounds (ft.lbs.). 4. Go to kg.m row 0, column 5; reads 49.0
5 kg.m = 49 ft.lbs. Add to step 3.
1. Select Table V.
5. 950 + 5 kg.m = 6871 + 49 = 6920 ft.lbs.
2. Go to kg.m row 90, column 5; reads 687.1
955 kg.m = 6920 ft.lbs.
95 kg.m = 687.1 ft.lbs.
3. Multiply by 10:
950 kg.m = 6871 ft.lbs.
:
PART NUMBERS
Three Bond Komatsu
TB1374 VE7533
TB1521 TB1521
TB1104 1400265H1
TB1107 1400266H1
TB1110 790-129-9080
MODEL HD785-5LC
ENGINE SAA12V140ZE-2
ITEM MEASUREMENT CONDITIONS UNIT Standard Value Permissible Value
Power Mode 2350 ± 50 2350 ± 50
High Idle Economy Mode rpm 2300 ± 50 2300 ± 50
Shift down
1400 ± 50 1400 ± 50
(F2ŸF1 only) (F2ŸF1 only)
Shift up 2000 ± 50 2000 ± 50
Economy RPM
1350 ± 50 1350 ± 50
Mode
Shift down
1300 ± 50 1300 ± 50
• Engine water temp.: (F2ŸF1 only) (F2ŸF1 only)
Braking Shift up Within operating range. 2450 ± 50 2450 ± 50
Mode Shift down • Transmission oil temp.: 70° - 90°C 1550 ± 50 1550 ± 50
• Hydraulic oil temp.: 50° - 80°C
Set F1, F2 1500 1500
Auto Lock-up
RPM
Reset 2350 ± 10 2350 ± 10
4-3
3-L
TORQUE CONVERTER
Oil pressure at Engine @ high idle 8 ± 1 (113 ± 15) 8 ± 1 (113 ± 15)
inlet port
Engine @ low idle 1.3 ± 0.5 (18.5 ± 7) 1.3 ± 0.5 (18.5 ± 7)
• Oil temperature:
Oil pressure at Engine @ high idle 4 ± 0.5 (57 ± 14) 4 ± 0.5 (57 ± 14)
70° - 90°C (158° - 194°F)
outlet port Engine @ low idle
• Engine water temperature: kg/cm2 1.0 ± 0.5 (14 ± 7) 1.0 ± 0.5 (14 ± 7)
Lock-up oil Engine @ high idle Within operating temperature (psi) 16.0 ± 0.5 (230 ± 10) 16.0 ± 0.5 (230 ± 10)
pressure • Hydraulic oil temperature:
Engine @ low idle 16.0 ± 0.5 (230 ± 10) 16.0 ± 0.5 (230 ± 10)
50° - 80°C (122° - 176°F)
Main relief Engine @ high idle 39.0 ± 2 (555 ± 29) 39.0 ± 2 (555 ± 29)
pressure
Engine @ low idle 34.5 ± 2 (490 ± 29) 34.5 ± 2 (490 ± 29)
TRANSMISSION CONTROL VALVE SET PRESSURE
Engine @ high idle 16.5 ± 1.5 (235 ± 20) 16.5 ± 1.5 (235 ± 20)
L, H, 4th clutch
Engine @ low idle 16.5 ± 1.5 (235 ± 20) 16.5 ± 1.5 (235 ± 20)
On actual truck
Engine @ high idle 20.5 ± 1.5 (290 ± 20) 20.5 ± 1.5 (290 ± 20)
3rd clutch Engine @ low idle 20.5 ± 1.5 (290 ± 20) 20.5 ± 1.5 (290 ± 20)
Engine @ high idle 31.5 ± 1.5 (450 ± 20) 31.5 ± 1.5 (450 ± 20)
1st, 2nd clutch • Oil temperature:
Engine @ low idle 70° - 90°C (158° - 194°F) 31.5 ± 1.5 (450 ± 20) 31.5 ± 1.5 (450 ± 20)
Engine @ high idle • Engine water temperature: kg/cm2 30 ± 1.5 (435 ± 20) 30 ± 1.5 (435 ± 20)
R clutch Within operating temperature (psi)
Engine @ low idle 30 ± 1.5 (435 ± 20) 30 ± 1.5 (435 ± 20)
• Hydraulic oil temperature:
Engine @ high idle 17 ± 2 (242 ± 28) 17 ± 2 (242 ± 28)
modulation Checker
• Oil temp.: 50° - 80°C (122° - 176°F) kg/cm2 (2986 +215 / - 0.0
) (2986 +215 / - 0.0
)
Relief Pressure (psi)
Engine @ Lo idle • Engine: Full throttle +10/ - 0.0 +10/ - 0.0
185 185
• Demand valve relief valve +140 / - 0.0 +140 / - 0.0
(2630 ) (2630 )
BRAKE PEDAL
Operating Force kg Max 30 Max 30
(lbs.) (Max. 66) (Max. 66)
• Tip of pedal
Travel mm (in.) 78 ± 8 78 ± 15
(3 ± 0.3) (3 ± 0.6)
RETARDER CONTROL LEVER
Operating Force kg 1.0 - 4.0 0.5 - 6.0
• At point 10 mm (0.4 in) from tip of lever (lbs.) (2.2 - 8.8) (1.1 - 13.2)
Travel degrees 0 - 90 ± 3 0 - 90 ± 3
PARKING BRAKE LEVER
Operating Force • Tip of lever kg (lbs.) Max. 2.0 (Max. 4.4) 3.0 (6.6)
EMERGENCY BRAKE LEVER
Operating Force • Tip of lever kg 0.01 - 0.02 Max. 0.05
(lbs.) (0.02 - 0.04) (Max. 0.10)
AIR GOVERNOR
• Pressure at which air is stored and
Set pressure circuit is unloaded when air pressure is 8.3 ± 0.3 8.3 ± 0.3
kg/cm2
raised from 0 kg/cm2 (0 psi) with (120 ± 4.3) (120 ± 4.3)
engine at full throttle. (psi)
PARKING BRAKE
• With 91 ton payload
Braking Capacity (sin θ) • After adjusting clearance between disc % Min. 15 Min. 15
and pad
Starting Test • F2 rpm Min. 2070 Min. 2070
• Torque converter stall
HOIST LEVER
HOLD ⇒ Max. 10 (22) Max. 10 (22)
RAISE
RAISE ⇒ Automatically reset Automatically reset
HOLD
Verify normal resistance value listed below: 1. Turn key switch OFF.
Lock-up Solenoid L/CT (male)
Between (1) - (2) 30 - 80Ω 2. Disconnect L/CT
Exhaust Brake Verify normal resistance value listed below: 1. Turn key switch OFF.
Solenoid SL5 (male)
Between (1) - (2) 20 - 60Ω 2. Disconnect SL5.
HSW (male)
LSW (male)
Fill Switch RSW (male) Verify normal resistances listed below: 1. Turn key switch OFF.
2. Disconnect switch
1SW (male) Switch OFF Between (1) and >1 MΩ
connector
chassis
2SW (male)
3SW (male)
4SW (male)
Engine Speed Sensor E12 Verify normal resistance listed below: 1. Turn key switch OFF.
(male) 2. Disconnect E12
Between (1) - (2) 500 - 1000Ω
DECKS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B2-3
1. Disconnect the ground wire between the nega- 1. Lower deck section onto truck and align cap-
tive terminal of the batteries and the frame. screw mounting holes.
2. Disconnect all air hoses and electrical wiring 2. Remove lifting device and
leading from the right deck. Disconnect ground 3. Install capscrews (2, Figure 2-4) and washers.
strap between right deck and frame. Tighten capscrews to standard torque.
3. Attach a lifting device to the deck.
4. Remove the four (4) mounting capscrews (2,
Figure 2-4).
5. Remove deck from truck.
BODY PIN
Inspection
VENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B4-4
Cleaning
The fuel tank is provided with a drain and a cleaning
port in the side that allows steam or solvent to be uti-
lized in cleaning tanks that have accumulated foreign
material.
It is not necessary to remove the tank from the truck
for cleaning of sediment, however rust and scale on
the walls and baffles may require complete tank
removal. This allows cleaning solutions to be in con-
tact with all interior surfaces by rotating the tank in
various positions, etc.
Prior to a cleaning procedure of this type, all vents,
fuel gauges, and hose connections should be
removed and temporarily sealed. After all scale, rust,
and foreign material have been removed, the tempo-
rary plugs can be removed.
If a tank has been damaged and requires structural
repair, carry out such repairs before final cleaning. A
small amount of light oil should be sprayed into the
tank to prevent rust if the tank is to remain out of ser-
vice. All openings should be sealed for rust preven-
tion.
ENGINE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C4-1
RADIATOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C3-3
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C3-3
Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C3-5
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C3-5
FAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C3-6
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C3-6
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C3-6
Installation Installation
1. Lift cooler up in place and secure with mounting 1. Inspect fan carefully before installation. If
capscrews. blades are bent or cracks are evident, install a
new fan.
2. Connect brake cooling oil lines and water cool-
ant lines to cooler. 2. Clean mounting surfaces thoroughly and install
spacer on fan hub.
3. Fill radiator and brake cooling oil tank to proper
levels with proper fluids as specified in Section 3. Lift fan into position and install over pilot diame-
P, Lubrication and Service. ter of hub.
4. Install the capscrews and lockwashers and
torque to standard torque. Use alternating pat-
tern and increasing levels of torque until all cap-
screws are evenly torqued.
5. Install fan guard around fan if separated during
removal.
6. Install radiator, hood, grille and water piping as
specified in Section B or earlier in this section.
7. Refill with coolant.
1. Fan Belt
2. Adjustment Nut
3. Tensioner Assembly
4. Tensioner Pulley
ENGINE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C4-2
GENERAL INSTRUCTIONS
• Prior to disassembly or removal, tag or mark all
air lines, oil lines, fuel lines and electrical
connections to assure correct assembly at time
of engine installation. Most electrical components
have harness connectors that can be
disconnected quickly. Refer to Section D for
additional information regarding connector types
and disconnect instructions.
• Plug all ports and cover all hose fittings or
connections when disconnected to prevent dirt or
foreign material from entering.
• Additional component disconnection and hookup
steps may be required during engine removal FIGURE 4-1. HEATER RELAY
and installation, depending on optional
1. By-pass Filter 3. Heater Relay
equipment installed at the factory or by the end
user. Refer to Section M for additional 2. Fuel Filter
information regarding optional equipment.
2. Disconnect water pump pipes (1, Figure 4-2)
and hose (3).
PREPARATION FOR ENGINE REMOVAL 3. Disconnect ground terminal (2) and alternator
output wire (4). Disconnect A/C compressor
Position the truck in work area with adequate
clutch and heater relay at filters behind alterna-
overhead clearance to permit raising the
dump body. tor.
BATTERY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D2-3
Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D2-3
Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D2-3
Maintenance and Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D2-4
Spillage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D2-5
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D2-8
Pressure Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D2-8
Check Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D2-8
Timer Solenoid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D2-8
MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D2-10
Prelub™ System Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D2-10
Starter/Prelub Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D2-10
Check Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D2-10
Timer Solenoid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D2-10
Troubleshooting Prelub Starter Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D2-11
Storage
Spillage
Addition of acid will be necessary if considerable
electrolyte has been lost through spillage. Before
adding acid, make sure battery is fully charged. This
is accomplished by putting the battery on charge and
taking hourly specific gravity readings on each cell.
When all the cells are gassing freely and three suc-
cessive hourly readings show no rise in specific grav-
ity, the battery is considered charged. Additional acid
may now be added. Continue charging for another
hour and again check specific gravity. Repeat the
above procedure until all cells indicate a specific
gravity of 1.260-1.265 corrected to 80°F (27°C).
NOTE: Use 1.400 strength sulfuric acid when making
specific gravity adjustments. Acid of higher strength
will attack the plates and separators before it has a
chance to diffuse into the solution.
If the temperature of the electrolyte is not reasonably
close to 80°F (27°C) when the specific gravity is FIGURE 2-1. BATTERY DISCONNECT SWITCH
taken, temperature should be corrected to 80°F HOOKUP
(27°C):
1. R.H. Deck Structure 3. Battery Box
• For every 10°F (5°C) below 80°F (27°C), 0.004 2. Battery Disconnect 4. Battery Relay
should be SUBTRACTED from the specific Switch Switches
gravity reading.
• For every 10°F (5°C) above 80°F (27°C), 0.004
should be ADDED to the reading.
Operation
The basic operating principles are explained as fol- Capacitor C1 protects the generator diodes from high
lows (Refer to Figure 2-2): transient voltages and suppresses radio interference.
Resistor R5 prevents current leakage through TR3 at
As the rotor begins to turn, the permanent magne-
high temperatures. Diode D5 prevents high transient
tism therein induces voltages in the stator windings.
voltages in the field coil when the field current is
The voltages across the six diodes cause current to
decreasing. Resistor R7, capacitor C3, and resistor
flow to charge the battery.
R4, all act to cause transistors, TR2 and TR1, to turn
Current from the stator flows through the three on and off more quickly.
diodes to resistor R6 and the base-emitter of TR2
and TR1 to turn these transistors on. Current also Magnetizing The Rotor
flows from the stator through the diode trio D1, D2 The rotor normally retains magnetism to provide volt-
and D3, the field coil and transistor TR1, returning to age build-up when the engine is started. After disas-
the stator through the other three diodes. All stator sembly or servicing, however, it may be necessary to
current, except through the diode trio D1, D2 and D3, reestablish the magnetism. To magnetize the rotor
flows through the six diodes connected to the stator. connect the alternator to the battery in a normal man-
Current flow through R1, R2 and R3 causes a volt- ner, then momentarily connect a jumper lead from
age to appear at zener diode D4. When the voltage the battery positive post to the relay “R” terminal.
becomes high enough due to increasing generator
speed, D4 and the base-emitter of TR3 conduct cur-
rent and TR3 turns on. TR2 and TR1 then turn off,
decreasing the field current and the system voltage
decreases. The voltage at D4 decreases, D4 and
TR3 turn off, TR2 and TR1 turn back on and the sys-
tem voltage increases. This cycle then repeats many
times per second to limit the system voltage as deter-
mined by the setting of the potentiometer R2.
• Pump
• Timer Solenoid Pressure Switch
• Oil pressure switch
The pressure switch (7, Figure 2-3) is a 0.18 kg/cm2
• Oil suction line (2.5 psi), normally closed (N.C.) switch, located so
• Oil outlet line that it can sense oil pressure after the engine oil has
passed through the filters.
• Check valve
• Electrical harness
Check Valve
The Prelub™ starter is an electric starter motor which The oil pressure supply hose has a check valve
has an extended armature shaft to drive an attached installed between the Prelub™ unit and the engine.
oil pump (1, Figure 2-4) at the brush end of the The check valve prevents the passage of oil from the
starter. engine back to the pan after the engine is started.
The oil flow through the valve is toward the engine as
The Prelub Starter mounting is the same as that indicated by an arrow on the valve.
used for the standard starter. Engine oil is drawn
through a suction hose attached to the oil pan, and Timer Solenoid
then returned to the engine through an outlet line
The timer solenoid (6) controls the prelubrication
attached to the engine oil supply ahead of the filters.
cycle. Current is supplied to the timer through the
NOTE: Before starting engine in cold weather, refer keyswitch. The ground path is completed by the nor-
to the Operation & Maintenance Manual, Section 3 mally closed pressure switch which is preset to open
for proper starting procedure. at 0.18 kg/cm2 (2.5 psi).
When the switch opens, current is redirected to the
standard starter solenoid for engine cranking, follow-
ing a 3 second delay.
OPERATION
The Prelub™ starter is activated when the operator
turns the key switch and holds it in the START posi-
tion. The normal starter solenoid is bypassed and the
current flows to the Prelub™ Starter Solenoid Timer.
When this Solenoid Timer is activated, current flows
to the Prelub™ Starter motor, but does not engage DO NOT attempt to jump start the truck using the
the starter pinion gear. The motor drives the Prelub™ terminals on the timer solenoid. INTERNAL DAM-
pump assembly which will deliver approximately 57 AGE TP THE TIMER WILL RESULT.
liters (15 gallons) of oil per minute to the engine.
Timer Solenoid
Inspect Timer Solenoid for physical damage and to
verify wiring is in good condition.
1. Prelubrication Phase- Begins when the key 2. Delay and Crank Phase- Begins when the
switch is held in the start position. A circuit is pressure switch opens. A 3 second delay pre-
provided to ground through the normally cedes the crank mode.
closed pressure switch. The circuit is inter-
rupted upon opening of the pressure switch
when the Prelub pressure reaches 0.18 kg/
cm2 (2.5 psi).
Starter prelubricates continuously regardless of key Indicates Prelub Timer Solenoid contacts have
switch position. welded.
a. Low voltage can cause relay failure.
b. Jump starting of the vehicle with a voltage
that is higher than was designed for the sys-
tem, can cause solenoid contacts to weld.
Starter delays and cranks. No prelubrication mode. If an operator indicates the ignition is totally dead,
make certain the key is being held in the crank posi-
tion for 3 to 4 seconds. If the engine cranks after a
short delay, this indicates that a ground connection
to the pressure switch has been broken. Without a
ground path, the prelubrication unit will proceed to
delay and crank.
a. Check the wire to the pressure switch. If the
wire is removed or cut, replace it.
b. Check the ground strap to engine block. If
the ground strap is missing the block is not
grounded.
c. Check the pressure switch for an open cir-
cuit. Remove the wire, then check for an
open circuit between the switch terminal
and the switch base. If open, replace the
pressure switch.
Starter has very long prelubrication cycle. Except for severe cold weather starts, the Prelub
cycle should not exceed 45 seconds.
a. Low oil pressure.
b. Make sure correct oil viscosity is being used
in respect to outside temperature. (Refer to
engine manufacturer's specifications).
c. Check for suction side air leaks, loose con-
nections, cracked fittings, pump casting, or
hose kinks and blockage.
d. Make sure the suction hose is a -20. Reduc-
ing hose diameter will reduce pump output
dramatically.
e. Check the oil pressure switch for the correct
location. Be certain that it has not been
moved into a metered oil flow, as in a
bypass filter or governor assembly.
Starter has no prelubrication, no delay and no If the starter is totally inoperative and no prelubrica-
crank. tion, no delay and crank, this indicates a possible
failure of the prelubrication timer solenoid.
Remove the wire from the pressure switch (ground
wire) and activate machine starter switch for several
seconds.
a. If the starter delays- then cranks, the Prelub
Timer Solenoid is bad. Replace the timer
solenoid assembly.
b. If the starter is still inoperative, check the
vehicle starter switch. Make sure proper
voltage is available to the Prelub Timer
Solenoid when the key is activated.
Starter prelubricates, delays, then does not crank. Indication is either a timer failure, or starter problem.
a. Pace a jumper wire to the starter solenoid
“S” post. If the engine starts to crank,
replace the Prelub Timer Solenoid.
b. If engine fails to crank when the “S” post is
energized with voltage, check starter bendix
solenoid and starter pinion drive.
OPERATION: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D3-17
This switch is used by the operator to control the When the switch is "out", normal position, the light in
idle speed of the engine. The switch when pushed the switch OFF, this is the automatic position. In this
"in" the light in the switch will be ON, is in the man- position the engine is controlled automatically
ual position. This provides for LOW engine idle depending on operating status of the truck. The fol-
speed. In this position the operator has greater con- lowing chart outlines the conditions for the engine
trol for movement in confined spaces, such as park- idle speed.
ing or driving in or out of service areas.
OUTLINE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D4-39
1. Disconnecting connectors
When disconnecting the connectors, hold the
connectors and not the wires (Figure 4-7). For
connectors held by a screw, loosen the screw
fully, then hold the male and female connectors
in each hand and pull apart. For connectors
which have a lock tab, press down the tab with
your thumb and pull the connectors apart.
NOTE: Never pull with one hand. FIGURE 4-7. DISCONNECTING CONNECTORS
Precautions when performing arc welding on the FIGURE 4-17. CONTROLLER BOX
truck.
• Disconnect all wiring harness connectors
connected to the controller box. Attach the arc
welding ground close to the welding point.
Sealing openings
• After any piping or component is removed, the
openings should be sealed with caps, plugs,
tapes, or vinyl bags to prevent any dirt or dust
form entering. If the opening is left open or is
blocked with a rag, there is danger of dirt entering
or of the surrounding area becoming dirty from
the leaking oil.
• Do not simply drain oil out on to the ground,
collect it and dispose of it properly.
FIGURE 4-20. OIL PUMP WITH FILTER
Do not let any dirt or dust get in during refilling
operations.
• Be careful not to let any dirt or dust get in when
re-filling with hydraulic oil. Always keep the oil
filler and the area around it clean. Also use clean
pumps or oil containers.
• An oil filtering device is highly recommended. If
an oil filtering device is used, it is possible to
remove dirt that has collected during storage.
Flushing operations
• After disassembling and assembling the
equipment, or changing the oil, use flushing oil to
remove the contaminants, sludge, and old oil
from the system.
• Normally, flushing is carried out twice: primary
flushing is carried out with flushing oil, and
secondary flushing is carried out with the
specified oil.
FIGURE 4-21. OIL FLUSHING
Cleaning operations
• After repairing the equipment (pump, control
valve, etc.) or when running the truck, carry out
oil cleaning to remove the sludge or
contaminants in the oil circuit.
• The oil cleaning equipment is used to remove the
ultra fine (about 3m) particles that the filters
installed on the truck are unable to remove.
• The location (Loc.) column in the following tables shows the X/Y
position of individual electrical connectors on the truck in Figures 4-
23, 4-24, 4-25, 4-26 and 4-27.
• The connector number listed in these illustrations may be preceded
with a "CN-" on the electrical schematic.
R23E Socket 5 Governor cut relay (electronic SP1 1-pin conn 1 AM/FM cassette
governor specification) SP2 1-pin conn 1 AM/FM cassette Z7
R25 Socket 5 Transmission cut relay V5 SP3 1-pin conn 1 AM/FM cassette
R27 Socket 5 Hazard relay U5 SP4 1-pin conn 1 AM c8
R28 Socket 6 Hazard lamp relay X3
(Systems Normal)
OPTIONAL CONTROLLERS
(If Installed)
Note: The following should be observed while performing steps 1 through 5, page 37.
• This shows that the fault first occurred 1151 • Shows that the fault last occurred 1 hour ago.
hours ago.
L clutch (bit No. 1) and 2nd clutch (bit No. 5) are disen-
Return shift lever to N position gaged and applicable portion goes out
MONITOR PANEL
After the starting switch is turned ON, the monitor itself carries out self-diagnosis. After that, it goes to the normal
display.
Check the bulbs of the pilot and caution lamps by pressing the lamp check switch at the right edge of the panel.
For details of the service codes, see SERVICE CODE TABLE.
TRANSMISSION CONTROLLER
1. Self-diagnostic display, warning display The content of the self-diagnosis and warning is displayed by a
2-digit LED code.If any abnormality is detected during self-diagnosis, the fault occurrence data is sent to the
network and the action code is displayed on the monitor panel. The electronic controller display on the moni-
tor panel may also light up. The warning lamp and buzzer may also be actuated.
The warning display is the detection of a fault in the pilot lamp display sensor systems and warnings and
warning actuations. If problems are detected, the warning lamp and buzzer may also be actuated.
Defective monitor panel display sensor system [b2,b7 are for A.2, A.3 B 1
mechanical governor specification machine only] b.3, b.4
b.2, b.7
Mistaken connector connection C.1 E 1
Explanation of symbols: [ ] 1 - 8: indicates that there are display patterns from 1 to 8 that appear in the [ ] portion.
1. : Lock - up clutch related parts
2. : H clutch related parts
3. : L clutch related parts
4. : 1st clutch related parts
5. : 2nd clutch related parts
6. : 3rd clutch related parts
7. : 4th clutch related
8. : R clutch related parts
|_| : Blank (no display)
NOTE: See the next page for explanation of the symbols used in the action of controller column.
5. Apply exhaust brake during travel test. (When traveling in lock - up, operate the exhaust brake switch then
the accelerator released)
6. If there is a fault in the sensor system, turn the key switch OFF - ON.
C Speed range held, . . . . . . . . . . . . . .because of a fault condition, the controller judges it is impossible to
but when lever is shift gear, so it holds the gear range.
moved to N, N is held
B Travel possible, but . . . . . . . . . . . . . .the controller automatically stops the functions in the faulty system.
some functions
are inoperative-
F Travel possible . . . . . . . . . . . . . . . . .the controller works normally
Display method: The code display starts with the faults that have occurred in order, and after completing the dis-
play of the content of all the faults, the display returns to the first code display. It continues to repeat this order. If
the fault is repaired, it returns to the normal display 5 minutes after the repair.
To make full use of the memory function to clearly display when the failure occurred and what failures have already
been corrected, keep strictly to the procedure given below.
Deleting service code from memory
For details of the method of deletion, see Method of deleting trouble data from memory (page D4-48)Carry out
troubleshooting, and when the fault has been repaired, the self-diagnostic display returned to normal, to delete the
transmission controller service codes from memory, turn the starting switch OFF, then turn it ON again, and check
the past faults in memory have been deleted.
For details, see Monitor Panel Action Codes And Service Mode Function, Method of deleting trouble data from
memory.
(if the data have been deleted, 8.8 is displayed for 3 seconds, then the display shows the part number, and after
3.5 seconds, the display returns to the normal display of 0.0 or 0.C)
Note 1: “Existing” means that the problem is still occurring; “history” means that the problem occurred in the past.
Note 2: If the problem is still existing, the alarm buzzer will also sound. (When the central warning lamp is ON).
2. Distinguishing conditions
Even with the same fault (problem), the method of troubleshooting may differ according to the model, compo-
nent, or problem. In such cases, the fault (problem is further divided into sections marked with small letters
(for example, a) ), so go to appropriate section to carry out troubleshooting.
If the troubleshooting chart is not divided into sections, start troubleshooting from the first check item in the
fault.
3. General precautions
When carrying out troubleshooting for the fault (problem), precautions that apply to all items are given at the
top of the page and marked with*.
The precautions marked * must always be followed first before carrying out the check inside the (box).
5. Troubleshooting tools
When carrying out the troubleshooting, prepare the necessary troubleshooting tools. For details, see Tools
For Testing, Adjusting, And Troubleshooting.
A diagram or chart is given for the connector type, installation position, and connector pin number. When car-
rying out troubleshooting, see this chart for details of the location for inspection and measurement of the wir-
ing connector and the pin number appearing in the troubleshooting flow chart for each fault.
FIGURE 4-50.
FIGURE 4-51.
Adjustment procedure
NOTE: Turn off the power, then remove the
electronic monitor and carry out adjustments at the
rear of the speedometer.
1. Remove the rubber cap from # 2 port at the rear
of the speedometer.
2. When the rubber cap is removed, a rotary
FIGURE 4-52. ADJUSTING SPEEDOMETER
switch can be seen (See Figure 4-53).
3. Using a flat-headed screwdriver, turn this switch
and adjust to the values in the table below.
Switch position 0 1 2 3 4 5 6 7
Compensation (%) +7 +6 +5 +4 +3 +2 +1 +0
Switch position 8 9 A B C D E F
Compensation (%) 0 -1 -2 -3 -4 -5 -6 -7
Reference
The model data are set with the right rotary switch
(switch 1) and the network connection data are set
with the left rotary switch (switch 2). The relationship
of the settings and the model data and network con-
nection data is as shown in the tables below.
A. Outline
NOTE: If the transmission controller is going to be
used on another truck, delete the trouble data and
other data related to the current truck from the
memory of the transmission controller and PMC as
follows.
FIGURE 4-55. MODE SWITCHES
1. This function is used to delete data from the 1. Bulb Check Switch 3. Mode Switch (Black)
memory of the transmission controller and 2. Mode Switch (Red)
PMC.
2. This function is effected by operating bulb
check switch (1, Figure 4-55) and mode change
switches (2) (the red switch at the front of the
truck and (3) (the black switch at the rear of the
machine) and using the S-NET to send the
command from the monitor panel to each con-
troller to delete the data from memory.
3. The monitor panel accepts the operation for
their function only when the key switch is ON
and the engine is stopped. In addition, each
controller also accepts the operation for this
function only when the key switch in ON and the
engine is stopped.
4. To prevent the data from being deleted from the
memory of the wrong controller, an instrument
panel caution display (5, Figure 4-56) lights up
to make it possible to confirm the controller from FIGURE 4-56. CONFIRMING DATA DELETION
which the data is being deleted.
5. Caution Light
C. Method of operation
1. (Shown at location A in figure 4-57) - Operate
bulb check switch (1, Figure 4-58) and both
mode change switches (2) & (3). Keep the
switches pressed to the ON position at the
same time for at least 2.5 seconds, then
release them. (When the switches are
released, they will return automatically to the
OFF position).
2. (Shown at location B in Figure 4-57) - No par-
ticular operation is needed; after Step 1 and
display (3) is shown, the display automatically
changes to display (4).
(Shown at location D in Figure 4-57) - Operate bulb
check switch (1, Figure 4-58) and both mode change FIGURE 4-58. MODE SWITCHES
switches (2) & (3). Keep the switches pressed to the
1. Bulb Check 3. Mode Switch (Black)
2. Mode Switch (Red)
E. Remarks
The memory data deletion mode is also in the normal
mode except for the other mechatronics caution dis-
play (6).
A-21 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D5-77
a) Torque converter oil temperature overheat warning displayed . . . . . . . . . . . . . . . . . . . . . . . . D5-77
b) Engine water temperature overheat warning displayed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D5-77
c) Air pressure drop warning displayed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D5-77
d) Retarder brake oil temperature overheat warning displayed . . . . . . . . . . . . . . . . . . . . . . . . . . D5-77
e) Engine overrun actuated displayed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D5-78
f) Engine overshoot actuated displayed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D5-78
Display code Fault Conditions Details of fault Check the wiring harnesses and equipment given below:
♦ Possible causes: Disconnection, short circuit in wiring harness (+): Positive, (-): Negative
The top code in the Display code column shows the monitor panel display and the bottom code (in [ ] ) shows the
transmission controller LED display. (< less than - > greater than)
1. Between ATC1 (9), (17) - (8) (V): 20 - 30 V Cannot carry out control Transmission suddenly shifts to
2. Between TMB (11) - TMC (1) (V): 20 - 30 V (Transmission is placed in Neutral) Neutral during propel or truck can-
3. Between J07 - J06 (V): 20 - 30 V not move again
4. BT1 fuse No. 10 is not blown
1. Defective controller
b005 Double engagement of clutch 2. Defective fill switch
(E. ↔ 0.5) ♦ With double engagement of clutch, input 3. Between H SW - TM3 (3) - ATC5A (12)
(E.C ↔ 0.5) of fill sensor signal was detected Between L SW - TM3 (6) - ATC5A (10)
Double engagement: Actuated for 2.1 - Between R SW - TM3 (9) - ATC5A (13)
4.7 sec Between 1 SW - TM4 (3) - ATC5A (14)
Between 2 SW - TM4 (6) - ATC5A (15)
Between 3 SW - TM4 (9) - ATC5A (11)
Between 4 SW - TM4 (12) - ATC5A (16)
The top code in the Display code column shows the monitor panel display and the bottom code (in [ ] ) shows the
transmission controller LED display. (< less than - > greater than)
H SW (male) - chassis TM3 (male) (3) - chassis ATC5A (female) (12) - chassis Actuates Transmission suddenly
L SW (male) - chassis TM3 (male) (6) - chassis ATC5A (female) (10) - chassis
transmission cut relay shifts to Neutral during
and shifts to Neutral propel or truck cannot
R SW (male) - chassis TM3 (male) (9) - chassis ATC5A (female) (13) - chassis
> 1M Ω or > 1 M Ω move again
1 SW (male) - chassis TM3 (male) (3) - chassis ATC5A (female) (14) - chassis between terminals
2 SW (male) - chassis TM3 (male) (6) - chassis ATC5A (female) (15) - chassis
3 SW (male) - chassis TM3 (male) (9) - chassis ATC5A (female) (11) - chassis
4 SW (male) - chassis TM3 (male) (12) - chassis ATC5A (female) (16) - chassis
1. Between ATC2 (14) - chassis (V): 12V 12V output circuit OFF Transmission suddenly
2. Between TMB (1) - chassis (V): 12V (does not give +12V) shifts to Neutral during
3. Between SF (1) - (2) (V): 12V Shifts to Neutral propel or truck cannot
4. Each terminal of ATC2 (14), TMB (1), DF (1) - chassis: > 1MΩ move again
Even when engine speed
1. Between ATC2 (13) - chassis: 20 - 60 Ω Only gives self-diag- exceeds 2,600 rpm and
2. Between SL4 (male) (1) - (2): 20 - 60 Ω nostic display; does not engine overruns, brake to
3. Between ATC1 (13) - ATC1 (4) (V): 20 30 V take any action prevent overrun is not
actuated
b017 Accelerator signal circuit Disconnection, defec- 1. Between ATC3B (11) - TMA (13) - C/V.T (1)
(E. ↔ 1.7) tive adjustment of mount, link out of position 2. Defective adjustment of clearance of sensor mount
(E.C ↔ 1.7) ♦ Voltage between ATC3B (11) sand chassis 3. Damaged accelerator pedal link
• > 4.7 ± 0.1V 4. Defective acceleration sensor
• < 0.6± 0.1V 5. Defective engine controller acceleration sensor power source circuit
b019 Short circuit with ground in transmission valve 1. Between (+) ATC3B (9) - TM4 (13) - C/V.T (1)
(E. ↔ 1.9) oil temperature circuit Between (-) ATC3A (16) - TM4 (14) - C/V.T (2)
(E.C ↔ 1.9) ♦ When transmission oil temperature sensor 2. Defective transmission valve lil temperature sensor
signal is more than 150°C
b022 Clutch slipping or defective transmission 1. Input shaft 1) Between N1 (1) - TM2 (1) - ATC3A (2)
| speed sensor. Speed sensor 2) Between N1 (2) - TM2 (2) - ATC3A (14)
b028 ♦ When the input shaft speed, intermediate 2. Output shaft 1) Between N3 (1) - TM2 (1) - ATC3A (5)
(E. ↔ 2.2) shaft speed, output shaft speed are con- Speed sensor 2) Between N3 (2) - TM2 (6) - ATC3A (14)
(E.C ↔ 2.2) verted and it is found that there is an fault 3. One of following clutches worn or damaged: H, L, 1st, 2nd, 3rd, 4th, R
| with either the HL clutch or speed clutch.
(E. ↔ 2.8)
(E.C ↔ 2.8)
b022 Defective H clutch or input shaft speed sensor See items for display codes b022 - b028
(E. ↔ 2.2) (E. ↔ 2.2, E.C ↔ 2.2, E. ↔ 2.8, E.C ↔ 2.8)
(E.C ↔ 2.2)
b023 Defective L clutch or input shaft speed sensor See items for display codes b022 - b028
(E. ↔ 2.3) system (E. ↔ 2.2, E.C ↔ 2.2, E. ↔ 2.8, E.C ↔ 2.8
(E.C ↔ 2.3)
The top code in the Display code column shows the monitor panel display and the bottom code (in [ ] ) shows the
transmission controller LED display. (< less than - > greater than)
1.
ATC3A (female) Ω 1. Transmission suddenly
Between (2) - (14)
shifts to Neutral during
Shift to Neutral propel or truck cannot
Between (12 - (14) 500 - 1,000 Ω. move again
Between (3) - (14) 2. Power is lost when in
Each terminal - chassis > 1 MΩ propel, and trans-mis-
2. See TESTING AND ADJUSTING OF TRANSMISSION sion repeatedly shifts
when going uphill
3. Transmission oil is not black enough to indicate problem
See items for display
1. Between ATC3A (female) (2) - (14): 500 - 1,000 Ω. Shift to Neutral codes b022 - b028
2. See TESTING AND ADJUSTING OF TRANSMISSION, H clutch portion. (E.↔2.2, E.C↔2.2,
E.↔2.8, E.C↔2.8)
See items for display
1. Between ATC3A (female) (2) - (14): 500 - 1,000 Ω. Shift to Neutral codes b022 - b028
2. See TESTING AND ADJUSTING OF TRANSMISSION, L clutch portion. (E.↔2.2, E.C↔2.2,
E.↔2.8, E.C↔2.8)
b024 Defective 1st clutch or output shaft See items for display codes b022 - b028
(E. ↔ 2.4) speed sensor (E. ↔ 2.2, E.C ↔ 2.2, E. ↔ 2.8, E.C ↔ 2.8
(E.C ↔ 2.4)
b025 Defective 2nd clutch or output shaft See items for display codes b022 - b028
(E. ↔ 2.5) speed sensor (E. ↔ 2.2, E.C ↔ 2.2, E. ↔ 2.8, E.C ↔ 2.8)
(E.C ↔ 2.5)
b026 See items for display codes b022 - b028
(E. ↔ 2.6) Defective 3rd clutch or output speed sensor (E. ↔ 2.2, E.C ↔ 2.2, E. ↔ 2.8, E.C ↔ 2.8
(E.C ↔ 2.6)
b027 Defective 4th clutch or output shaft See items for display codes b022 - b028
(E. ↔ 2.7) speed sensor (E. ↔ 2.2, E.C ↔ 2.2, E. ↔ 2.8, E.C ↔ 2.8
(E.C ↔ 2.7)
b028 Defective R clutch or output shaft See items for display codes b022 - b028
(E. ↔ 2.8) speed sensor (E. ↔ 2.2, E.C ↔ 2.2, E. ↔ 2.8, E.C ↔ 2.8
(E.C ↔ 2.8)
b032 Defective H clutch pressure control valve 1. Dirt caught in H clutch pressure control spool
(E. ↔ 3.2) 2. Between HSW - TM3 (3) - ATC5A (12)
(E.C ↔ 3.2)
b033 Defective L clutch pressure control valve 1. Dirt caught in L clutch pressure control spool
(E. ↔ 3.3) 2. Between LSW - TM3 (6) - ATC5A (10)
(E.C ↔ 3.3)
b034 Defective 1st clutch pressure control valve 1. Dirt caught in 1 clutch pressure control spool
(E. ↔ 3.4) 2. Between 1SW - TM4 (3) - ATC5A (13)
(E.C ↔ 3.4)
b035 Defective 2nd clutch pressure control valve 1. Dirt caught in 2 clutch pressure control spool
(E. ↔ 3.5) 2. Between 2SW - TM4 (6) - ATC5A (14)
(E.C ↔ 3.5)
b036 Defective 3rd clutch pressure control valve 1. Dirt caught in 3 clutch pressure control spool
(E. ↔ 3.6) 2. Between 3SW - Tm4 (9) - ATC5A (15)
(E.C ↔ 3.6)
b037 Defective 4th clutch pressure control valve 1. Dirt caught in 4 clutch pressure control spool
(E. ↔ 3.7) 2. Between 4SW - TM4 (12) - ATC5A (11)
(E.C ↔ 3.7)
b038 Defective R clutch pressure control valve 1. Dirt caught in R clutch pressure control spool
(E. ↔ 3.8) 2. Between RSW - TM3 (9) - ATC5A (16)
(E.C ↔ 3.8)
The top code in the Display code column shows the monitor panel display and the bottom code (in [ ] ) shows the
transmission controller LED display. (< less than - > greater than)
1. Between ATC3A (female) (3) - (14): 500 - 1,000 Ω Shift to See items for display codes b022 - b028
2. See TESTING AND ADJUSTING OF TRANSMISSION, 1st clutch portion. Neutral (E. ↔2.2, E.C↔2.2, E. ↔2.8, E.C↔2.8)
1. Between ATC3A (female) (3) - (14): 500 - 1,000 Ω Shift to See items for display codes b022 - b028
2. See TESTING AND ADJUSTING OF TRANSMISSION, 2nd clutch portion. Neutral (E. ↔2.2, E.C↔2.2, E. ↔2.8, E.C↔2.8)
1. Between ATC3A (female) (3) - (14): 500 - 1,000 Ω Shift to See items for display codes b022 - b028
2. See TESTING AND ADJUSTING OF TRANSMISSION, 3rd clutch portion. Neutral (E. ↔2.2, E.C↔2.2, E. ↔2.8, E.C↔2.8)
1. Between ATC3A (female) (3) - (14): 500 - 1,000 Ω Shift to See items for display codes b022 - b028
2. See TESTING AND ADJUSTING OF TRANSMISSION, 4th clutch portion. Neutral (E. ↔2.2, E.C↔2.2, E. ↔2.8, E.C↔2.8)
1. Between ATC3A (female) (3) - (14): 500 - 1,000 Ω Shift to See items for display codes b022 - b028
2. See TESTING AND ADJUSTING OF TRANSMISSION, R clutch portion. Neutral (E. ↔2.2, E.C↔2.2, E. ↔2.8, E.C↔2.8)
H SW (male) - chassis TM3 (male) (3) - chassis ATC5A (female) (12) - chas-
sis
> 1M Ω or > 1 M Ω
H SW (male) - chassis TM3 (male) (6) - chassis ATC5A (female) (10) - chas- between terminals Shift to Transmission suddenly shifts to Neutral
sis
Neutral during propel or truck cannot move again
H SW (male) - chassis TM3 (male) (9) - chassis ATC5A (female) (16) - chas-
sis
H SW (male) - chassis TM3 (male) (3) - chassis ATC5A (female) (13) - chas-
sis
H SW (male) - chassis TM3 (male) (6) - chassis ATC5A (female) (14) - chas-
sis
b052 Defective H clutch flow control valve 1. Between HSW - TM3 (3) - ATC5A (12)
(E. ↔ 5.2) 2. Defective H clutch fill switch
(E.C ↔ 5.2)
b053 Defective L clutch flow control valve 1. Between LSW - TM3 (6) - ATC5A (10)
(E. ↔ 5.3) 2. Defective L clutch fill switch
(E.C ↔ 5.3)
b054 Defective 1st clutch flow control valve 1. Between 1SW - TM4 (3) - ATC5A (13)
(E. ↔ 5.4) 2. Defective 1st clutch fill switch
(E.C ↔ 5.4)
The top code in the Display code column shows the monitor panel display and the bottom code (in [ ] ) shows the
transmission controller LED display. (< less than - > greater than)
Normal controller display: Shows 0.0 or 0.C Shift to Neutral Transmission suddenly shift to Neutral during propel
or truck cannot move again
Normal controller display: Shows 0.0 or 0.C Shift to Neutral Transmission suddenly shift to Neutral during propel
or truck cannot move again
Normal controller display: Shows 0.0 or 0.C Shift to Neutral Transmission suddenly shift to Neutral during propel
or truck cannot move again
Normal controller display: Shows 0.0 or 0.C Shift to Neutral Transmission suddenly shift to Neutral during propel
or truck cannot move again
Normal controller display: Shows 0.0 or 0.C Shift to Neutral Transmission suddenly shift to Neutral during propel
or truck cannot move again
Normal controller display: Shows 0.0 or 0.C Shift to Neutral Transmission suddenly shift to Neutral during propel
or truck cannot move again
Normal controller display: Shows 0.0 or 0.C Shift to Neutral Transmission suddenly shift to Neutral during propel
or truck cannot move again
Normal controller display: Shows 0.0 or 0.C Shift to Neutral Transmission suddenly shift to Neutral during propel
or truck cannot move again
When each gear range is engaged using the shift checker, the fill
switch signal is given with the combinations shown in Table 1
Table 1 Relationship between gear range and fill switch signal Gear range used
during propel is 1. Gearshifting during propel becomes impossible.
H L 1 2 3 4 R maintained 2. If shift lever is in Neutral, it becomes impossible to
R O O If shift lever is in move truck
F1 O O Neutral, transmission
is held in Neutral
F2 O O
F3 O O
F4 O O
F5 O O
F6 O O
F7 O O
When each gear range is engaged with the shift checker, the fill See items for display 1. Gearshifting during propel becomes impossible.
switch signal is issued for the combinations in Table 1 of the items for codes b052 - b058 2. If shift lever is in Neutral, it becomes impossible to
display codes b052 - b058 (E. ↔ 5.2, E.C ↔ 5.2, move truck
(E. ↔ 5.2, E.C ↔ 5.2, E. ↔ 5.8, E.C ↔ 5.8 E. ↔ 5.8, E.C ↔ 5.8)
When each gear range is engaged with the shift checker, the fill See items for display 1. Gearshifting during propel becomes impossible.
switch signal is issued for the combinations in Table 1 of the items for codes b052 - b058 2. If shift lever is in Neutral, it becomes impossible to
display codes b052 - b058 (E. ↔ 5.2, E.C ↔ 5.2, move truck
(E. ↔ 5.2, E.C ↔ 5.2, E. ↔ 5.8, E.C ↔ 5.8) E. ↔ 5.8, E.C ↔ 5.8)
b055 Defective 2nd clutch flow control valve 1. Between 2SW - TM4 (6) - ATC5A (14)
(E. ↔ 5.5) 2. Defective 2nd clutch fill switch
(E.C ↔ 5.5)
b056 Defective 3rd clutch flow control valve 1. Between 3SW - TM4 (9) - ATC5A (15)
(E. ↔ 5.6) 2. Defective 3rd clutch fill switch
(E.C ↔ 5.6)
b057 Defective 4th clutch flow control valve 1. Between 4SW - TM4 (12) - ASTC5A (11)
(E. ↔ 4.4) 2. Defective 4th clutch fill switch
(E.C ↔ 4.4)
b058 Defective R clutch flow control valve 1. Between RSW - TM3 (9) - ATC5A (16)
(E. ↔ 5.8) 2. Defective R clutch fill switch
(E.C ↔ 5.8)
The top code in the Display code column shows the monitor panel display and the bottom code (in [ ] ) shows the
transmission controller LED display. (< less than - > greater than)
Check with Table 2 for the items for display codes b071 - b078 Actuates transmission cut relay and shifts to Transmission suddenly shifts
(E. ↔ 7.1, E.C ↔ 7.1, E. ↔ 7.8, E.C ↔ 7.8) Neutral to Neutral during propel or
truck cannot move again
Check with Table 2 for the items for display codes b071 - b078 Actuates transmission cut relay and shifts to Transmission suddenly shifts
(E. ↔ 7.1, E.C ↔ 7.1, E. ↔ 7.8, E.C ↔ 7.8) Neutral to Neutral during propel or
truck cannot move again
Check with Table 2 for the items for display codes b071 - b078 Actuates transmission cut relay and shifts to Transmission suddenly shifts
(E. ↔ 7.1, E.C ↔ 7.1, E. ↔ 7.8, E.C ↔ 7.8) Neutral to Neutral during propel or
truck cannot move again
Check with Table 2 for the items for display codes b071 - b078 Actuates transmission cut relay and shifts to Transmission suddenly shifts
(E. ↔ 7.1, E.C ↔ 7.1, E. ↔ 7.8, E.C ↔ 7.8) Neutral to Neutral during propel or
truck cannot move again
Check with table 2 for the items for display codes b071 - b078 Actuates transmission cut relay and shifts to Transmission suddenly shifts
(E. ↔ 7.1, E.C ↔ 7.1, E. ↔ 7.8, E.C ↔ 7.8) Neutral to Neutral during propel or
truck cannot move again
b076 Short circuit in 3rd clutch pressure control See items for display codes b071 - b078
(E. ↔ 7.6) solenoid (E. ↔ 7.1, E.C ↔ 7.1- E. ↔ 7.8, E.C ↔ 7.8
(E.C ↔ 7.6)
b0077 Short circuit in 4th clutch pressure control See items for display codes b071 - b078
(E. ↔ 7.7) solenoid (E. ↔ 7.1, E.C ↔ 7.1- E. ↔ 7.8, E.C ↔ 7.8)
(E.C ↔ 7.7)
b0078 Short circuit in R clutch pressure control See items for display codes b071 - b078
(E. ↔ 7.7) solenoid (E. ↔ 7.1, E.C ↔ 7.1- E. ↔ 7.8, E.C ↔ 7.8)
(E.C ↔ 7.7)
b091 1. 1) Lock - up Between (+) L/U.T (1) - ATC1 (1), Between (-) L/U.T (2) - ATC1 (8), (16)
| 2) H clutch Between (+) H.PS (1) - ATC2 (9), Between (-) H.PS (2) - ATC2 (19)
b098 Disconnection in pressure control solenoid 3) L clutch Between (+) L.PS (1) - ATC2 (7), Between (-) L.PS (2) - ATC2 (17)
(E. ↔ 9.1) ♦When it is tried to disengage the clutch, 4) 1st clutch Between (+) 1.PS (1) - ATC2 (2), Between (-) 1.PS (2) - ATC2 (13)
(E.C ↔ 9.1) the pressure control solenoid output is 5) 2nd clutch Between (+) 2.PS (1) - ATC2 (4), Between (-) 2.PS (2) - ATC2 (15)
| turned ON, but the solenoid current does 6) 3rd clutch Between (+) 3.PS (1) - ATC2 (3), Between (-) 3.PS (2) - ATC2 (13)
(E. ↔ 9.8) not flow 7) 4th clutch Between (+) 4.PS (1) - ATC2 (8), Between (-) 4.PS (2) - ATC2 (18)
(E.C ↔ 9.8) 8) R clutch Between (+) R.PS (1) - ASTC2 (5), Between (-) R.PS (2) - ATC2 (15)
b091
(E. ↔ 9.1) Disconnection in lock-up pressure control See items for display codes b091 - b098
(E.C ↔ 9.1) solenoid (E. ↔ 9.1, E.C ↔ 9.1, E. ↔ 9.8, E.C ↔ 9.8
b092 Disconnection in H clutch pressure control See items for display codes b091 - b098
(E. ↔ 9.2) solenoid (E. ↔ 9.1, E.C ↔ 9.1, E. ↔ 9.8, E.C ↔ 9.8)
(E.C ↔ 9.2)
b093 Disconnection in L clutch pressure control See items for display codes b091 - b098
(E. ↔ 9.3) solenoid (E. ↔ 9.1, E.C ↔ 9.1, E. ↔ 9.8, E.C ↔ 9.8
(E.C ↔ 9.3)
b094 Disconnection in 1st clutch pressure control See items for display codes b091 - b098
(E. ↔ 9.4) solenoid (E. ↔ 9.1, E.C ↔ 9.1, E. ↔ 9.8, E.C ↔ 9.8
(E.C ↔ 9.4)
b095 Disconnection in 2nd clutch pressure control See items for display codes b091 - b098
(E. ↔ 9.7) solenoid (E. ↔ 9.1, E.C ↔ 9.1, E. ↔ 9.8, E.C ↔ 9.8
(E.C ↔ 9.7)
b096 Disconnection in 3rd clutch pressure control See items for display codes b091 - b098
(E. ↔ 9.6) solenoid (E. ↔ 9.1, E.C ↔ 9.1, E. ↔ 9.8, E.C ↔ 9.8)
(E.C ↔ 9.6)
b097 Disconnection in 4th clutch pressure control See items for display codes b091 - b098
(E. ↔ 9.7) solenoid (E. ↔ 9.1, E.C ↔ 9.1, E. ↔ 9.8, E.C ↔ 9.8)
(E.C ↔ 9.7)
b098 Disconnection in R clutch pressure control See items for display codes b091 - b098
(E. ↔ 9.8) solenoid (E. ↔ 9.1, E.C ↔ 9.1, E. ↔ 9.8, E.C ↔ 9.8
(E.C ↔ 9.8)
The top code in the Display code column shows the monitor panel display and the bottom code (in [ ] ) shows the
transmission controller LED display. (< less than - > greater than)
b0A2 Short circuit with ground in torque converter 1. Between (+) ATC3B (7) - TM2 (7) - TC.SE (1)
(E. ↔ A.2) oil temperature Between (-) ATC3A (16) - TMB (9) - TMC (5) - TM2 (8) - TC.SE (2)
(E.C ↔ A.2) ♦When torque converter oil temperature 2. Defective torque converter oil temperature sensor
sensor signal is more than 150°C
b0A3 Disconnection in fuel level sensor 1. Between (+) ATC5B (5) - TMA (15) - J09M (12), (15) - J02 (1) - 26 (1)
(E. ↔ A.3) ♦Input voltage: > 4 V 2. Defective fuel sensor
(E.C ↔ A.3)
b0b2 Short circuit with ground in cooling water 1. Between (+) ATC5B (5) - TMA (7) -J09M (12), (15) - J02 (1) - 26 (1)
(E. ↔ b.2) temperature sensor Between (-) ATC5A (16) - TMB (9) - J09M (13), (16) - J02 (3) - 26 (2)
(E.C ↔ b.2) ♦When input resistance of cooling water 2. Defective coolant water temperature sensor
temperature sensor signal is more than
170 Ω
b0b3 Disconnection in brake air pressure sensor 1. Between (+) ATC3B (2) - TMA (7) - RH4 (1) - SR5 (1)
(E. ↔ b.3) ♦ When input resistance of brake air pres- Between (-) ATC5A (16) - TMB (9) - RH4 (10) - SR5 (2)
(E.C ↔ b.3) sure sensor signal is more than 3,000 Ω 2. Defective brake air pressure sensor
The top code in the Display code column shows the monitor panel display and the bottom code (in [ ] ) shows the
transmission controller LED display. (< less than - > greater than)
ATC3A (female) TM2 (male) N1 (male) Ω Gear range used during 1. Gearshifting becomes impossible.
Between (2) - (14) Between (1) - (2) Between (1) - (2) 500 - 1,000 Ω
propel is maintained 2. If shift lever is in Neutral, it
If shift lever is in Neutral, becomes impossible to move the
Each terminal - chassis >1MΩ
transmission is held in truck again unless it is stopped.
Neutral
ATC3B,3A (female) TM2 (female) TC.SE (male) Ω Only gives self-diagnos- No display at all is given on torque
Between (7) - (16) Between (7) - (8) Between (10 - (2) tic display; does not take converter oil temperature gauge dis-
1 KΩ - 100 KΩ any action play on monitor panel.
(7) - chassis (7) - chassis (1) - chassis
When engine water temperature is between 25°C (normal temperature) and 100°C, condition is as shown in
table below. Only gives self-diagnos- No display at all is given on engine
ATC3B,3A (male) TMA, TMB (male) J09M J02 61 (W)
tic display; does not take water temperature gauge display on
any action monitor panel.
Between Between Between (12), (15) Between (1) - (3) Between (1) - (2)
(5) - (16) (15) - (9) - (13), (16) 37 Ω
|
(5) - chassis (15) - chassis (12), (15) - chassis (1) - chassis (1) - chassis 4Ω
ATC3B,3A (male) TMA, TMB (male) RH4, RH1 SR5 Ω Only gives self-diagnos- No display at all is given on air pres-
Between (2) - (16) Between (7) - (9) Between (1) - (10) Between (1) - (2) tic display; does not take sure gauge display on monitor
3 - 1,000 Ω any action panel.
(2) - chassis (7) - chassis (1) - chassis (10) - chassis
b0b4 Short circuit with ground in retarder brake oil 1. Between (+) ATC3b (8) - tmd (5) - J02 (10) - 64 (1)
(E. ↔ b.4) temperature sensor Between (-) ATC3A (16) - TMB (9) - J02 (9) - 64 (2)
(E.C ↔ b.4) ♦ When retarder brake oil temperature sen- 2. Defective retarder brake oil temperature sensor
sor signal is more than 150°C
b0b7 Disconnection, short circuit with ground in 1. Between ATC3B (12) - TMD (15) - J02 (2) - 27 (3)
(E. ↔ b.7) engine oil pressure sensor Between (+) ATC3A (6) - TMA (16) - J09M (11) - (14) - J01 (11) - 27 (2)
(E.C ↔ b.7) ♦ Voltage between ATC3B (12) - chassis 2. Defective voltage circuit inside controller
• 4.6 ± 0.1 V 3. Defective engine oil pressure sensor
• 0.4 ± 0.1 V
Improper connection of connector
b0C1 ♦ After the key switch is turned "ON", de- 1. Between ATC5A (1) - ATC1 (16).
(E. ↔ C1) pending on the wiring harness, the model 2. Defective contact of ATC5A connector
(E.C ↔ C1) selection signal does not match
b0C4 Short circuit with ground in BCV rear solenoid 1. Defective BCV relay R04
(E. ↔ C.4) ♦ BCV output terminal voltage 2. Between ATC (11) - TMB (13) - R04 (1)
(E.C ↔ C.4) • When actuated: > 11V or above
• When not actuated: < 11V or below
b0C8 Short circuit in BCV rear solenoid 1. Defective BCV relay R04
(E. ↔ C.8) ♦ BCV output terminal voltage 2. Between ATC (11) - TMB (13) - R04 (2)
(E.C ↔ C.8) • When actuated: > 11V or above
• When not actuated: < 11V or below
b0d1 Transmission filter clogging warning 1. Between (+) ATC5A (6) - TMD (6) - J02 (13) - 52 (10
(E. ↔ d.1) ♦ When the transmission oil filter switch is Between (-) J03 (8) - 52 (2)
(E.C ↔ d.1) OFF with the torque converter outlet port 2. Defective transmission filter sensor
oil temperature 50°C or above.
b0d5 Tilt warning display 1. Between (+) ATC5A (5) - TMD (2) - SR3 (1)
(E. ↔ d.5) ♦ When the machine tilt angle switch is OFF. Between (-) SR3 (2) - GND.ER
(E.C ↔ d.5) 2. Defective tilt sensor
b0d6 Drop in radiator water level warning display 1. Between (+) ATC5B (15) - TMD (4) - J02 (7) - 01 (9) - 03 (1)
(E. ↔ d.6) ♦ When the engine cooling water level switch Between (-) 03 (2) - GND.16
(E.C ↔ d.6) is OFF. 2. Defective radiator water level sensor
The top code in the Display code column shows the monitor panel display and the bottom code (in [ ] ) shows the
transmission controller LED display. (< less than - > greater than)
ATC3B,3A (male) TMD, TMB (male) J02 64 Ω Only gives self-diagnos- No display at all is given on
Between (8) - (16) Between (5) - (9) Between (10) - (9) Between (1) − (2)
tic display; does not take retarder oil temperature gauge
2k Ω - 20k Ω
(25°C - 120°C)
any action display on monitor panel.
(8) - chassis (5) - chassis (10) - chassis (1) − chassis
ATC3B TMD J02 27 (V) Only gives self-diagnos- Drop in engine oil pressure
(12) - chassis (15) - chassis (2) - chassis (3) − chassis
tic display; does not take cannot be detected.
0.4 - 4.6 V any action
Between (2) - (3)
ATC1 TMB R04 (V) Ω Only gives self-diagnos- BCV is not actuated
(11) - chassis (13) - chassis (1) - chassis 20 − 30 V tic display; does not take
Between relay (1) 100 - 500 Ω any action
and (2)
ATC1 TMB R04 (V) Ω Only gives self-diagnos- BCV in mistakenly actuated
(11) - chassis (13) - chassis (1) - chassis 20 − 30 V tic display; does not take
Between relay (1) 100 - 500 Ω
any action
and (2)
b0d7 Battery charge warning display 1. Between ATC3B (1) - TMD (1) - J01 (1) - alternator terminal R
(E. ↔ d.7) ♦ When battery charge switch is OFF with 2. Defective charging circuit
(E.C ↔ d.7) engine speed at 500 rpm or above.
b0F5 Engine oil pressure drop warning 1. Between ATC3B (12) - TMD (15) - J02 (2) - 27 (3)
(E. ↔ F.5) ♦ When fault is recognized in the engine 2. Defective engine lubricating oil circuit
(E.C ↔ F.5) speed at 700 rpm or above. 3. Defective engine oil pressure sensor
b0E5 Steering oil temperature overheat warning 1. Between ATC3A (11) - TMA (8) - J01 (6) - 21 (1)
(E. ↔ E.5) ♦ When steering oil temperature switch in 2. Defective steering oil temperature sensor
(E.C ↔ E.5) ON.
b0F6 Rear brake oil pressure warning display 1. Between (+) ATC5A (8) - TMC (12) - J)3 (2) - BLSL (1)
(E. ↔ F.6) ♦ When brake stroke switch is ON for 2 sec- Between BLSL (2) - BLSR (1)
(E.C ↔ F.6) onds. Between (-) BLSR (2) - GND.67
2. Defective brake stroke sensor
b0d3 Engine water temperature overheat warning Abnormal rise in engine water temperature.
(E. ↔ d.3) ♦ When engine water temperature sensor
(E.C ↔ d.3) signal is above 102°C
The top code in the Display code column shows the monitor panel display and the bottom code (in [ ] ) shows the
transmission controller LED display. (< less than - > greater than)
When steering oil temperature is 25°C (normal temperature), condition is as shown in table below. If there is a fault when 1. If operations are continued, oil
ATC3A TMA J01 21 — key switch is turned may leak.
(11) - chassis (8) - chassis (6) - chassis (1) - chassis No continuity "ON", transmission is 2. Mechatronics display is not
held at Neutral. given.
When brake stroke is normal, condition is as shown in table below. Only gives self-diag- 1. If operations are continued, oil
ATC5A TMD J03 BLSL nostic display; does not may leak.
(8) - chassis (12) - chassis (2) - chassis (1) - chassis take any action 2. Mechatronics display is not
— — — (1) - (2), (2) - chassis
Continuity given.
• When fuse BT1 (No. 10) is normal.If it is blown, check for a short circuit
with the ground in the wiring harness between the fuse and controller.
• When the battery is normal.
• Before carrying out troubleshooting, check that all the related connectors are properly inserted.
• Always connect any disconnected connectors before going on to the next step.
• When fuses BT1 (10) (19 - 20) and BT2 (8) (15 - 16) are normal.If it is blown, check for a short circuit with the
ground inside the controller and in the wiring harness between the fuse and controller.
• When the battery is normal.
• Before carrying out troubleshooting, check that all the related connectors are properly inserted.
• Always connect any disconnected connectors before going on to the next step.
• When fuse BT2 (8) (15 - 16) is normal.If it is blown, check for a short circuit with the ground inside the controller
and in the wiring harness between the fuse and controller.
• When the battery is normal.
• Before carrying out troubleshooting, check that all the related connectors are properly inserted.
• Always connect any disconnected connectors before going on the next step.
• When fuse BT1 (10) (19 - 20) is normal.If it is blown, check for a short circuit with ground inside the controller
and in the wiring harness between the fuse and controller.
• When the battery is normal.
• Before carrying out troubleshooting, check that all the related connectors are properly inserted.
• Always connect any disconnected connectors before going on to the next step.
• When the key switch is turned to ON with the shift lever at a position other than N, or when the power source is
momentarily cut when moving.
• Before carrying out troubleshooting, check that all the related connectors are properly inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before carrying out troubleshooting, check that all the related connectors are properly inserted.
• Always connect any disconnected connectors before going on to the next step.
• Displays disconnection, short circuit, or short circuit with chassis ground in transmission cut relay system.
• Before carrying out troubleshooting, check that all the related connectors are properly inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before carrying out troubleshooting, check that all the related connectors are properly inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before carrying out troubleshooting, check that all the related connectors are properly inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before carrying out troubleshooting, check that all the related connectors are properly inserted.
• Always connect any disconnected connectors before going on to the next step.
• Check that the mounting bolts of the input shaft speed sensor are not loose.
• Before carrying out troubleshooting, check that all the related connectors are properly inserted.
• Before carrying out troubleshooting, check that all the related connectors are properly inserted.
• Always connect any disconnected connectors before going on to the next step.
or
• Before carrying out troubleshooting, check that all the related connectors are properly inserted.
• Always connect any disconnected connectors before going on to the next step.
or
TABLE 1.
ATC3A (female) N1 (male) Resistance
Between (2) - (14) Between (1) - (2) 500 Ω - 1000 Ω
Between (2) & chassis Between (1) & chassis > 1M Ω
or
TABLE 1.
ATC3A (female) N2 (male) Resistance
Between (2) - (14) Between (1) - (2) 500 Ω - 1000 Ω
Between (12) & chassis Between (1) & chassis > 1M Ω
A-8 c) Related electrical diagram
or
• Check that the mounting bolts of the speed sensor are not loose.
• Before carrying out troubleshooting, check that all the related
connectors are properly inserted.
• Always connect any disconnected connectors before going on to the next step.
Table 1.
ATC3A (female) N2 (male) Resistance
Between (3) - (14) Between (1) - (2) 500 Ω - 1000 Ω
Between (3) & chassis Between (1) & chassis > 1M Ω
or
Table 1.
ATC3A N2 Resistance
Between (2) - (14) Between (1) - (2) 500 Ω - 1000 Ω
Between (2) & chassis Between (1) & chassis > 1M Ω
TABLE 1.
ATC3A N2 Resistance
Between (3) - (14) Between (1) - (2) 500 Ω - 1000 Ω
Between (3) & chassis Between (1) & chassis > 1M Ω
Table 1.
ATC5B ATC1 Voltage
(10) - (8) > 15 V
(11) - (8) >1V
(12) - (8) >1V
(13) - (8) <1V
• Before carrying out troubleshooting, check that all the related connectors are properly inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before carrying out troubleshooting, check that all the related connectors are properly inserted.
• Always connect any disconnected connectors before going on to the next step.
Table 1
Lever position Terminal of TORQFLOW Voltage when position Voltage when position Shift lever
transmission controller is selected is not selected SF terminal
N ATC5B (3) < 1.0 V > 15.0 V SF (4)
R ATC5B (2) < 1.0 V > 15.0 V SF (3)
D ATC5B (4) < 1.0 V > 15.0 V SF (5)
5 ATC5B (5) < 1.0 V > 15.0 V SF (6)
4 ATC5B (6) < 1.0 V > 15.0 V SF (7)
3 ATC5B (7) < 1.0 V > 15.0 V SF (8)
L ATC5B (8) < 1.0 V > 15.0 V SF (9)
• Before carrying out troubleshooting, check that all the related connectors are properly inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before carrying out troubleshooting, check that all the related connectors are properly inserted.
• Always connect any disconnected connectors before going on to the next step.
Table 1
Connection of connector and fill switch Fill switch
Transmission controller When connected When Open
Service code display Corresponding connector and pin Fill switch Voltage Resistance Voltage Resistance
clutch number
b032
[E.↔ 3.2,E.C↔3.2] H clutch ATC5A (12) - H. SW <1V <1Ω 15 -25 V > 1 MΩ
b033
[E.↔ 3.3,E.C↔ 3.3] L clutch ATC5A (10) - L. SW <1V <1Ω 15 -25 V > 1 MΩ
b034
[E.↔ 3.4,E.C↔ 3.4] 1 clutch ATC5A (13) - 1. SW <1V <1Ω 15 -25 V > 1 MΩ
b035
[E.↔ 3.5,E.C↔ 3.5] 2 clutch ATC5A (14) - 2. SW <1V <1Ω 15 -25 V > 1 MΩ
b036
[E↔ 3.6,E.C↔ 3.6] 3 clutch ATC5A (15) - 3. SW <1V <1Ω 15 -25 V > 1 MΩ
b037
[E.↔ 3.7,E.C↔ 3.7] 4 clutch ATC5A (11) - 4. SW <1V <1Ω 15 -25 V > 1 MΩ
b038
[E.↔ 3.8,E.C ↔ 3.8] R clutch ATC5A (16) - R. SW <1V <1Ω 15 -25 V > 1 MΩ
Table 1
Connection of connector and fill switch Fill switch
Transmission controller When connected When Open
Service code Corresponding connector and pin Fill switch Voltage Resistance Voltage Resistance
display clutch number
b042
[E.↔ 4.2,E.C↔4.2] H clutch ATC5A (12) - H. SW <1V <1Ω 15 -25 V > 1 MΩ
b043
[E.↔ 4.3,E.C↔ 4.3] L clutch ATC5A (10) - L. SW <1V <1Ω 15 -25 V > 1 MΩ
b044
[E.↔ 4.4,E.C↔ 4.4] 1 clutch ATC5A (13) - 1. SW <1V <1Ω 15 -25 V > 1 MΩ
b045
[E.↔ 4.5,E.C↔ 4.5] 2 clutch ATC5A (14) - 2. SW <1V <1Ω 15 -25 V > 1 MΩ
b046
[E↔ 4.6,E.C↔ 4.6] 3 clutch ATC5A (15) - 3. SW <1V <1Ω 15 -25 V > 1 MΩ
b047
[E.↔ 4.7,E.C↔ 4.7] 4 clutch ATC5A (11) - 4. SW <1V <1Ω 15 -25 V > 1 MΩ
b048
[E.↔ 4.8,E.C↔ 4.8] R clutch ATC5A (16) - R. SW <1V <1Ω 15 -25 V > 1 MΩ
When is displayed.
• Before carrying out troubleshooting, check that all the related connectors are properly inserted.
• Always connect any disconnected connectors before going on to the next step.
Go to Troubleshooting A-7b.
b-3) Inspecting transmission output shaft speed signal system, 1-4, R clutch (check clutch slip)
When is displayed.
Go to troubleshooting of A-7a.
• Before carrying out troubleshooting, check that all the related connectors are properly inserted.
• Always connect any disconnected connectors before going on to the next step.
Carry out troubleshooting of A-13 b-1) Fill switch signal.
Respond to the display as follows: 5.2 ↔ 4.2
5.3 ↔ 4.3
5.4 ↔ 4.4
5.5 ↔ 4.5
5.6 ↔ 4.6
5.7 ↔ 4.7
5.8 ↔ 4.8
or
DISCONNECTION IN PRES-
SURE CONTROL VALVE
SOLENOID DISPLAYED
• Before carrying out troubleshooting,
check that all the related connectors are properly inserted.
• Always connect any disconnected connectors before going on to the next step.
Table 1
Display Measurement location
7.2 Measurement item Normal value
Trouble-shooting 1 Troubleshooting 2
9.2
7.3 Resistance
Between ATC1 (9) - (19) Between HPS (1) - (2) 5 - 25 Ω
9.3 between (1) - (2)
7.4
Between ATC2 (7) - (17) Between 1 PS (1) - (2)
9.4
7.5
Between ATC2 (4) - (15) Between 2 PS (1) - (2)
9.5
7.6 Resistance between
Between ATC2 (3) - (13) Between 3 PS (1) - (2) >1MΩ
9.6 (2) - chassis ground
7.7
Between ATC2 (8) - (18) Between 4 PS (1) - (2)
9.7
7.8
Between ATC2 (5) - (15) Between RPS (1) - (2)
9.8
Table 2
Display Measurement location Measurement item Normal value
Troubleshooting 1 Troubleshooting 2 Resistance between (1) - (2) 30 - 80 Ω
7.1 Between ATC1(1) - Between LCT(1) -
9.1 Resistance between (2) - chassis ground >1MΩ
(8) (16) (2)
(It takes 30 seconds for the fuel gauge to change 1 level. Take this into account when carrying out troubleshoot-
ing).
• Before carrying out troubleshooting, check that all the related connectors are properly inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before carrying out troubleshooting, check that all the related connectors are properly inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before carrying out troubleshooting, check that all the related connectors are properly inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before carrying out troubleshooting, check that all the related connectors are properly inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before carrying out troubleshooting, check that the transmission oil filter is not clogged.
• Before carrying out troubleshooting, check that all the related connectors are properly inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before carrying out troubleshooting, check that all the related connectors are properly inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before carrying out troubleshooting, check that the cooling water level is not low.
• Before carrying out troubleshooting, check that all the related connectors are properly inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before carrying out troubleshooting, check that all the related connectors are properly inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before carrying out troubleshooting, check if the steering oil temperature is high.
• Before carrying out troubleshooting, check that all the related connectors are properly inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before carrying out troubleshooting, check if the engine oil pressure is low.
• Before carrying out troubleshooting, check that all the related connectors are properly inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before carrying out troubleshooting, check that all the related connectors are properly inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before carrying out troubleshooting, check that all the related connectors are properly inserted.
• Always connect any disconnected connectors before going on to the next step.
• This shows that there had been an abnormal rise in the torque
converter oil temperature.
• If the rise in the torque converter oil
• This shows that there had been an abnormal rise in the retarder brake oil temperature.
• If the rise in the retarder brake oil temperature is abnormal, see the Operation and Maintenance Manual.
• This shows that there has been engine overshoot (sudden spurt).
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D6-8
P-1 Check pattern for wiring harnesses between modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D6-8
P-2 Nothing on Monitor Panel Operates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D6-11
P-3 LH, RH Module and fuel gauge do not operate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D6-12
P-4 LH, RH Module and fuel gauge do not operate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D6-13
P-5 RH Module does not operate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D6-14
P-6 LH module does not operate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D6-15
P-7 Odometer does not operate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D6-16
P-8 Service meter does not operate correctly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D6-17
P-9 Central Warning Lamp does not operate, or
monitor panel detects fault code (monitor panel display) [A002] . . . . . . . . . . . . . . . . . . . . . . . . . .D6-18
P-10 Central warning lamp stays ON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D6-19
P-11 Alarm buzzer does not operate. or Monitor Panel detects fault code A003: . . . . . . . . . . .D6-20
P-12 Alarm buzzer continues to sound . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D6-21
P-13 All data from Shift Controller (speedometer, tachometer, shift indicator, etc.) is faulty (nothing is dis-
played, or display does not change), or
Monitor Panel detects service code A013, or service code A0018: . . . . . . . . . . . . . . . . . . . . . . .D6-22
P-14 Suspension mode, power/economy mode displays are faulty (nothing is displayed, or display does
not change), or Monitor Panel detects service code A016: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D6-23
P-15 Gauge displays are faulty (nothing is displayed or display does not change) . . . . . . . . . .D6-24
P-16 Cooling water level drop caution lamp does not operate, or
Monitor Panel detects service code A001: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D6-25
P-17 Cooling water level drop caution lamp stays ON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D6-26
P-18 Emergency steering pilot lamp does not operate, or
monitor panel detects service code A001: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D6-27
P-19 Emergency steering pilot lamp stays ON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D6-28
P-20 Engine oil pressure drop caution lamp does not operate, or
monitor panel detects service code A001: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D6-29
P-21 Engine oil pressure drop caution lamp stays ON. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D6-30
P-22 Exhaust brake (Optional) pilot lamp does not operate, or
monitor panel detects service code A001: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D6-31
P-23 Exhaust brake pilot lamp stays ON (Optional) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D6-32
P-24 Charging circuit fault caution lamp does not operate. or
monitor panel detects service code A001: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D6-33
P-25 Charging circuit fault caution lamp stays ON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D6-34
FAULT TROUBLESHOOTING
CODE FAULT CONDITION POSSIBLE CAUSE
NOTE: Check wiring harness circuits and components listed below for
short circuit, open circuit, etc.
1. Fault between lamp (+) and monitor panel. (Refer to P-16, 18, 20,
A001 Short circuit in Short circuit in output 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42 for troubleshooting
lamp output details.)
2. Defective lamp
Short circuit in Central 1. Between (+) DP08 pin 2 and WL pin 2.
A002 Warning Lamp output Short circuit in output
2. Defective central warning lamp
1. Between (+) DP08 pin 2 and BZ pin 2.
A003 Short circuit in alarm Short circuit in output 2. Defective alarm buzzer
buzzer output
A012 Network system fault Connection data does 1. Incorrect shift controller model selection setting
not match
1. Between (+) DP05 pin 3, TMD pin 10, and ATC4 pin 6.
2. Between (+) DP05 pin 4, TMD pin 12, and ATC4 pin 12.
A013 Network system fault Transmission Control-
ler system 3. Between (-) DP05 pin 5, TMD pin 9, and ATC4 pin 10.
4. Between (-) DP05 pin 5, TMD pin 11, and ATC4 pin 10.
5. Defective shift controller
1. Between (+) DP05 pin 3 and PMC pin 1.
A014 Network system fault PMC system 2. Between (+) DP05 pin 4 and PMC pin 2.
2. Between (+) DP05 pin 4, SU3 pin 13, and SSP1 pin 12.
A016 Network system fault Suspension
Controller 3. Between (-) DP05 pin 5, SU3 pin 12, and SSP2 pin 9.
4. Between (-) DP05 pin 5, SU3 pin 14, and SSP2 pin 9.
5. Defective Suspension Controller
1. Incorrect Shift Controller model selection setting.
2. Between (+) DP05 pin 3, TND pin 10, and ATC4 pin 6.
A018 Network system fault Model selection data 3. Between (+) DP05 pin 4, TND pin 12, and ATC4 pin 12.
4. Between (-) DP05 pin 5, TND pin 9, and ATC4 pin 10.
5. Between (-) DP05 pin 5, TND pin 11, and ATC4 pin 20.
6. Defective Shift Controller.
1. Between (+) DP05 pin 3 and PMC pin 1.
A019 Network system fault Option data 2. Between (+) DP05 pin 4 and PMC pin 2.
Central Warning Lamp ON: Voltage between 1. Other mechatronics caution lamp flashes. Central Warning Lamp always OFF.
DP08 pin 1 and WL pin 2 <0.1 volts. 2. Displays action code.
3. Central Warn. Lamp forcibly turned OFF.
Buzzer ON: Voltage between DP08 pin 2 and 1. Other mechatronics caution lamp flashes. Buzzer does not sound.
BZ pin 2 <0.1 volts. 2. Displays action code.
3. Alarm buzzer forcibly stopped.
Shift Controller model selection setting and 1. Other mechatronics caution lamp flashes. If the setting is for a truck with the electronic
actual mounting condition of Controller in net- 2. Displays action code. governor specification, engine output will
work match. decrease and engine speed may not
increase.
1. Resistance between (+) DP05 pin 3, TMD pin 1. Other mechatronics caution lamp flashes. For trucks with electronic governor specifica-
10, ATC4, pin 6 is 0 ohms. 2. Displays action code. tion, the engine mode switching, the engine
2. Resistance between (+) DP05 pin 4, TMD pin 3. Display is fixed for all data from Transmis- mode selection, or AISS may not work.
12, ATC4, pin 12 is 0 ohms. sion Controller (speedometer, tachometer, Engine output may be reduced or speed may
3. Resistance between (-) DP05 pin 5, TMD pin gauges, etc.) not increase.
9, ATC4, pin 10 is 0 ohms.
4. Resistance between (-) DP05 pin 5, TMD pin
11, ATC4, pin 10 is 0 ohms.
1. Resistance between (+) DP05 pin 3 and 1. Other mechatronics caution lamp flashes. MOM may not function properly at times. For
PMC pin 1 is 0 ohms. 2. Displays action code. trucks with electronic governor specification,
2. Resistance between (+) DP05 pin 4 and the engine output may be reduced or the
PMC pin 2 is 0 ohms. speed may not increase.
3. Resistance between (-) DP05 pin 5 and PMC
pin 3 is 0 ohms.
1. Resistance between (+) DP05 pin 3, SU3 pin 1. Other mechatronics caution lamp flashes. In some cases, suspension control is inoper-
9, SSP1 pin 2 is 0 ohms. 2. Displays action code. able.
2. Resistance between (+) DP05 pin 4, SU3 pin 3. Suspension mode display does not
13, SSP1 pin 12 is 0 ohms. change or all lamps go out.
3. Resistance between (-) DP05 pin 5, SU3 pin
12, SSP2 pin 9 is 0 ohms.
4. Resistance between (-) DP05 pin 5, SU3 pin
14, SSP2 pin 9 is 0 ohms.
1. Shift Controller model selection setting is cor- 1. Other mechatronics caution lamp flashes. In some cases, the transmission may remain
rect. 2. Displays action code. in neutral or the engine may remain at low
2. Resistance between (+) DP05 pin 3, TND pin 3. In addition to 1 & 2, only the speed unit, idle.
10, ATC4 pin 6 is 0 ohms. turn signal lamp, and high beam pilot lamp
3. Resistance between (+) DP05 pin 4, TND pin are displayed.
12, ATC4 pin 12 is 0 ohms.
4. Resistance between (-) DP05 pin 5, TND pin
9, ATC4 pin 10 is 0 ohms.
5. Resistance between (-) DP05 pin 5, TND pin
11, ATC4 pin 10 is 0 ohms.
1. Resistance between (+) DP05 pin 3 and 1. Other mechatronics caution lamp flashes. MOM may not function properly. For trucks
PMC pin 1 is 0 ohms. 2. Displays action code. with electronic governor specification, the
2. Resistance between (+) DP05 pin 4 and engine output may be reduced or speed may
PMC pin 2 is 0 ohms. not increase.
3. Resistance between (+) DP05 pin 5 and
PMC pin 3 is 0 ohms.
1. Engine mechatronics caution lamp flashes. In some cases, the engine may not start.
2. Displays action code. Engine output may be reduced or the speed
3. Engine Stop Lamp (red) flashes. may not increase.
1. Engine mechatronics caution lamp flashes. In some cases, the engine may not start.
2. Displays action code. Engine output may be reduced or the speed
3. Engine Protection Lamp (blue) flashes. may not increase.
1. Engine mechatronics caution lamp flashes. In some cases, the engine may not start.
2. Displays action code. Engine output may be reduced or the speed
3. Engine Check Lamp (yellow) flashes. may not increase.
NOTE: When troubleshooting the monitor panel, if The following instructions must be followed when
the item in the troubleshooting flow chart or the item troubleshooting the monitor panel and associated
in the "remedy" column indicates "carry out check of components and wire harnesses:
wiring harnesses between modules", refer to the
• Be certain all harnesses are properly inserted in
number displayed in the following tables and check the mating connectors.
the female connector of the wiring harnesses
between modules. • Before removing any harness connector, be
certain the key switch is in the OFF position.
• The key switch must remain in the OFF position
when performing the following checks on the
wiring harnesses.
Be certain truck wheels are blocked to prevent • Visually inspect harnesses and connectors for
movement during troubleshooting procedures. physical damage, insulation cracks, pin damage
etc.
X Y
No. CONNECTOR PIN No. SIGNAL NAME CONNECTOR PIN No.
DP11 1
A-1 1 VB (20V) DP04 1
A-2 2 LCD TX OUT DP10 3
A-3 3 LCD TX IN DP04 4
DP10 4
A-4 4 SCK DP04 5
DP10 5
A-5 5 LCD LOAD DP04 6
DP10 6
A-6 DP02 6 LCD COM DP04 7
DP10 7
A-7 7 RESET DP04 8
DP12 4
DP10 8
DP11 2
A-8 8 GND
DP08 16
DP05 12
DP12 2
A-9 1 P/S DATE DP04 3
A-10 DP10 2 SHIFT/LOAD DP04 2
B-1 1 VB (20V)
B-2 2 LCD TX OUT
B-3 3 LCD TX IN
B-4 DP02 4 SCK
B-5 5 LCD LOAD
B-6 6 LCD COM
B-7 7 RESET
B-8 1 P/S DATE
B-9 DP10 2 SHIFT/LOAD
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Refer to P-1 for Table b.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Refer to P-1 for Table b.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Refer to P-1 for Table a or b.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Refer to P-1 for Table a.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Refer to P-1 for Table a and b.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Refer to P-1 for Tables a and b.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• Before troubleshooting, verify all connectors related to the wiring harnesses between the modules are properly
inserted.
• Always connect any disconnected connectors before going on to the next step.
• The monitor panel saves trouble data for problems detected as [A013], [A014], [A015], [A016], [A018], or
[A019] together as service code [A011].
• If [A013], [A014], [A015], [A016], [A018], or [A019] are currently being detected, carry out repairs according to
the respective troubleshooting.
• If [A013], [A014], [A015], [A016], [A018], or [A019] are not currently being detected, the system has been reset
so the condition is normal.
• The monitor panel saves trouble data for problems detected as [A001], [A002], or [A003] together as fault code
[A000].
• If [A001], [A002], or [A003] are currently being detected, carry out repairs according to the respective
troubleshooting.
• If [A001], [A002], or [A003] are not currently being detected, the system has been reset so the condition is
normal.
This information is provided as a diagnostic tool for trained, experienced technicians only. Improper
trouble-shooting or repair can result in severe personal injury or death or property damage. See impor-
tant instructions in the Engine Service Manual.
SENSOR SPECIFICATIONS
H-7 Time lag is excessive when starting to move, or shifting gear . . . . . . . . . . . . . . . . . . . . . . . . . . .D8-11
H-10 Front brakes are ineffective, or effective only on one side . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D8-15
H-11 Rear brakes are ineffective, or effective on one side only . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D8-16
3 Truck starts normally in certain gear range c. Seized transmission clutch Replace
d. Defective speed clutch (oil leak) Replace
e. Defective shaft seal ring in speed clutch circuit Replace
f. Internal transmission damage Replace
g. Defective speed sensor Replace
a. Defective pump Replace
b. Defective transmission clutch seal ring, groove Replace
4 Truck does not move when oil temperature rises
c. Defective speed clutch (oil leak) Replace
d. Defective shaft seal ring in speed clutch circuit Replace
a. Clogged strainer Clean
5 Low at every gear
b. Air sucked in at suction side of pump Repair
range
c. Drop in pressure of main relief valve Repair or replace
(torque converter valve)
Transmission oil pressure is a. Defective ECMV Replace
6 low Becomes lower at b. Defective transmission clutch seal ring, groove Replace
certain speed range
c. Defective speed clutch (oil leak) Replace
d. Defective shaft seal ring in speed clutch circuit Replace
Indicator is unstable a. Clogged strainer Clean
7 and fluctuates exces-
b. Air sucked in at suction side of pump Repair
sively
8 When pressure pickup port plug is removed and a. Pump does not turn (defective PTO) Replace
engine is cranked, no oil comes out.
9 Modulation pressure is abnormal a. Defective ECMV Replace
10 Hydraulic pressure at pump outlet port is low a. Drop in pressure of main relief valve Repair or replace
(torque converter valve)
• Transmission hunts.
• Lock-up lamp flashes.
CAUSE REMEDY
Drop in main relief pressure Refer to H-6
Worn clutch seal ring
Determining Standard
There is some shock, but it is difficult to determine if the shock is excessive or not, so determine if it is excessive in
the following cases:
• It is clear that the shock has suddenly become excessive.
• The shock is excessive compared with other trucks of the same model.
Cause
• Improper operation due to dirt in the ECMV pressure control valve spool or flow detector valve spool. Improper
operation of the of the ECMV proportional solenoid.
• Improper operation due to dirt in the in the pressure control valve spool.
CAUSE REMEDY
Slipping or damaged torque converter lock-up clutch Repair or replace
NOTE: The above is the most probable cause, but for details, see Torque converter lock-up does not engage.
CAUSE REMEDY
Improper operation of ECMV for clutch which does not shift up Clean, repair, or replace
Defective piston seal ring, defective groove for clutch which does not shift up Replace
Drop in main relief pressure Adjust, clean, repair, or replace
CLUTCH
GEAR H L 4th 3rd 2nd 1st R
RANGE (rotating) (rotating)
R
N
F1
F2
F3
F4
F5
F6
F7
CLUTCH COMBINATION TABLE
.
No. PROBLEM CAUSE REMEDY
a. Clogged strainer Clean
1 Abnormal noise from between pump and filter b. Air sucked in at suction side of pump Repair
a. Defective pump Replace
b. Drop in pressure of main relief valve Adjust, repair, or
(torque converter valve) replace
2 Torque converter stall speed is high
c. Defective operation of torque converter relief valve, weak spring Adjust or replace
d. Cooler, piping beyond torque converter outlet port damaged Repair or replace
e. Internal torque converter damage (turbine rivet broken) Replace
3 Torque converter stall speed is low a. Drop in engine performance Repair
b. Defective torque converter stator clutch Replace
a. Clogged strainer Clean
4 Low at every gear
b. Defective pump Replace
range
c. Drop in pressure of main relief valve (torque converter valve) Adjust, repair, or
replace
Transmission pressure Indicator is unsta- a. Clogged strainer Clean
5 is low ble and fluctuates
b. Air sucked in at suction side of pump Repair
excessively
6 Low after entering a. See "Torque converter lock-up does not engage"
torque converter
lock-up
7 Hydraulic pressure at torque converter inlet a. Defective operation of torque converter relief valve, weak spring Adjust or replace
port is low (items 4 - 6 normal)
b. Cooler, piping beyond torque converter outlet port damaged Repair or replace
8 Hydraulic pressure at torque converter outlet a. Cooler, piping beyond torque converter outlet port damaged Repair or replace
port is low (item 7 normal)
9 Iron and aluminum particles stuck to strainer a. Defective torque converter stator clutch Replace
and drain plug of transmission case.
b. Internal torque converter damage (turbine rivet broken) Replace
10 Hydraulic pressure at pump outlet port is low a. Drop in pressure of main relief valve (torque converter valve) Adjust, repair, or
replace
11 When oil temperature rises, oil pressure drops a. Defective pump Replace
TRANSMISSION
CONTROLLER
No. PROBLEM SELF-DIAGNOSTIC CAUSE REMEDY
DISPLAY
(1) F1 is normal, but F2 is defective 2.5 3.5 4.5 4.5 a. 2nd clutch disc worn or seized, seal ring worn Replace
1 b. Improper operation of 2nd clutch ECMV Replace
(2) Returns to normal when replaced a. Improper operation of 2nd clutch ECMV Replace
with any ECMV except 2nd.
(1) F2 is normal, but F1 is faulty 2.4 3.4 4.4 5.4 a. 1st clutch disc worn or seized, seal ring worn Replace
2
b. Improper operation of 1st clutch ECMV Replace
(2) Returns to normal when replaced a. Improper operation of 1st clutch ECMV Replace
with any ECMV except 1st.
(1) F1 and F2 are normal, but F3 is 2.2 3.2 4.2 5.2 a. H clutch disc worn or seized, seal ring worn Replace
3 faulty
b. Improper operation of H clutch ECMV Replace
(2) Returns to normal when replaced a. Improper operation of H clutch ECMV Replace
with any ECMV except H.
(1) F1, F2, and F3 are normal, but F4 2.6 3.6 4.6 5.6 a. 3rd clutch disc worn or seized, seal ring worn Replace
4 is faulty
b. Improper operation of 3rd clutch ECMV Replace
(2) Returns to normal when replaced a. Improper operation of 3rd clutch ECMV Replace
with any ECMV except 3rd.
(1) F1 - F5 are normal, but F6 is faulty 2.7 3.7 4.7 5.7 a. 4th clutch disc worn or seized, seal ring worn Replace
5 b. Improper operation of 4th clutch ECMV Replace
(2) Returns to normal when replaced a. Improper operation of 4th clutch ECMV Replace
with any ECMV except 4th.
(1) F3, F5, and F7 are normal, but oth- 2.3 3.3 4.3 5.3 a. L clutch disc worn or seized, seal ring worn Replace
6 ers are faulty
b. Improper operation of L clutch ECMV Replace
(2) Returns to normal when replaced a. Improper operation of L clutch ECMV Replace
with any ECMV except 3rd.
(1) Only R is faulty 2.8 3.8 4.8 5.8 a. R clutch disc worn or seized, seal ring worn Replace
7
b. Improper operation of R clutch ECMV Replace
(2) Returns to normal when replaced a. Improper operation of R clutch ECMV Replace
with any ECMV except 3rd.
NOTE:
Remove all dirt and mud from around the ECMV, and clean it before replacing.
After replacing, tighten ECMV mounting bolts to 2.8 - 3.5 kg.m (20 - 25 ft. lbs) torque
NOTE: If oil temperature is normal but oil temperature gauge on truck goes above operating range, the gauge is
defective and should be replaced.
1 Oil pressure at master cylinder outlet port is low (outlet c. Clogged, crushed tube between relay valve and brake Repair or replace
port hose disconnected) chamber
d. Defective brake chamber seal Replace
e. Defective operation of master cylinder, worn packing Repair or replace
2 Air pressure at brake chamber inlet port is normal a. Defective brake chamber seal Replace
b. Defective operation of master cylinder, worn packing Repair or replace
a. Defective brake valve Repair or replace
3 Air pressure at brake chamber inlet port is low
b. Defective relay valve Repair or replace
c. Clogged, crushed tube between relay valve and brake Repair or replace
chamber
4 Air leakage from brake chamber a. Defective brake chamber seal Replace
5 Items 1 - 4 are normal, but slack adjuster outlet pres- a. Defective slack adjuster operation Repair or replace
sure is low
6 Items 1 - 5 are normal, but brake piston pressure is a. Worn piston seal ring Replace
low
7 Excessive contamination of cooling oil a. Excessive brake disc wear Replace
a. Worn piston seal ring Replace
8 Oil level in final drive case rises
b. Defective floating seal between brake cooling chamber Replace
and final drive
9 In item 7, brake piston oil pressure is normal a. Defective floating seal between brake cooling chamber Replace
and final drive
10 Items 1 - 5 are normal, but brake is ineffective or brak- a. Excessive brake disc wear Replace
ing effect is poor.
3 Item 1 is defective and hoist circuit relief pressure is c. Crushed suction tube Repair
low d. Drop in performance of hydraulic pump Replace
e. Drop in performance of steering pump Replace
f. Drop in demand valve relief valve pressure or defective seal Adjust, clean or
replace
4 Item 3 is abnormal and the sound of oil blowing a. Drop in demand valve relief valve pressure or defective seal Adjust, clean or
through relief valve is heard replace
5 Hoist circuit pressure is too high at engine high idle a. Improper operation of demand valve check valve Repair
(items 1 - 4 are normal)
b. Improper hoist valve check valve operation Repair
a. Drop in hoist valve relief valve pressure or defective seal Adjust or
6 Only hoist circuit relief pressure is low replace
b. Defective hoist cylinder Replace
TRANSMISSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F2-1
DRIVELINES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F5-1
TRANSMISSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F2-3
TRANSMISSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F2-32
Transmission Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F2-32
Transmission Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F2-34
FIGURE 2-5. TORQUE CONVERTER VALVE FIGURE 2-6. TORQUE CONVERTER VALVE
(External View) (Internal Components)
Operation
The oil from the hydraulic pump enters port (A, Fig-
ure 2-9), then passes through orifice (2) and goes to
port C.
When the hydraulic pressure in the circuit rises, the
pressure at port C also rises and pushes main relief
spool (1) to the left, in the direction of the arrow. The
oil at port A passes through port B and flows to the
torque converter circuit.
Actuating Pressure:
FIGURE 2-9. MAIN RELIEF VALVE
Engine @ high idle RPM: . . . . . . . . . . 39 ± 2 kg/cm2
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (555 ± 29 psi) 1. Main Relief Spool 2. Orifice
Operation
The oil from the main relief valve enters port B (Fig-
ure 2-10) and then passes through orifice (2) and
goes to port A. When the pressure in the circuit rises,
the pressure at port A also rises, and moves torque
converter relief spool (1) to the right in the direction of
the arrow. The oil at port B flows to port C and goes
to the transmission lubrication circuit.
Actuating Pressure:
FIGURE 2-10. TORQUE CONVERTER RELIEF
Engine @ high idle RPM . . . . . . . . . . . . 8 ± 1 kg/cm2 VALVE
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (113 ± 15 psi) 1. Relief Spool 2. Orifice
Operation
FIGURE 2-28.
FIGURE 2-29.
FIGURE 2-30.
FIGURE 2-31.
Disassembly
1. Before disassembly, flush the ECMV and valve
seat (paint at corners of the mating surfaces
must be removed thoroughly).
NOTE: Do not allow the solenoid connectors, fill
switch connectors, or harness to be exposed directly
to the water, etc.
2. Remove the mounting bolts (8, Figure 2-39)
from the ECMV assembly (10), and separate FIGURE 2-38. ECMV ASSEMBLY
the ECMV assembly from valve plate (12). 1. Valve Body 12. Spring
3. Remove solenoid connector (2, Figure 2-39) 2. Plug 13. Plug
and fill switch connector (3) from bracket. 3. Plug 14. O-ring
Loosen bolts (17). Gently remove the flow sen- 4. Pressure Control 15. Spring
sor valve fill switch (16) and bracket. Be careful Valve 16. Fill Switch
not to let spring (15) fall out of place. 5. Piston 17. O-ring
4. Remove cover plate (21, Figure 2-38). Remove 6. Spring 18. Bracket
plug (13) by installing a capscrew in the tapped 7. Shim 19. Bolt
hole for easier removal. Then, remove the flow 8. O-ring 20. Washer
detecting valve spring (12), valve spool (11), 9. Solenoid Valve 21. Cover Plate
and spring (15). 10. Bolt 22. O-ring
11. Flow Detection 23. Bolt
a. Examine valve body (1) and spool (11) as Valve
well as spring (15) for the existence of plat-
ing film pieces and other metallic particles. If
found, remove them.
b. If foreign matter has lodged in the valves or NOTE: Protect the valve plate (12, Figure 2-36) and
the pistons, or if their functional movement is the valve mating surfaces by applying masking tape,
not smooth, recondition them with an oil etc. Prevent dirt/dust from entering the transmission
stone, etc. by covering all openings. Place all removed parts in
5. Remove spring (6), shims (7), piston (5), and storage, being careful not to scratch any part.
valve (4) from the pressure control valve. Exam-
ine for any trapped foreign matter, seized spool,
or rough movement. Be careful not to lose
shims (7). Keep shims in storage, after confirm-
ing their quantity.
6. Remove the proportional solenoid valve (9).
a. Disconnect the chassis harness (6, Figure a. Press the clutch operation button for the
2-40) from the transmission control box (4). desired clutch.
b. Connect shift checker harness (3) (white b. With engine at high idle, measure and note
connectors) to the truck chassis harness the clutch pressure gauge reading.
connectors (SC1, SC2, SC3 & SC4) c. After reading is obtained, release accelera-
removed in step a. tor and press button selected in step a. to
c. Be certain shift checker power switch is Off. release clutch.
Connect harness (3) black connector to 7. Shut down the engine and remove the gauge
shift checker. installed in step 4 and replace port plug.
8. Repeat steps 4 through 7 as necessary to NOTE: One shim (thickness: 0.2 mm) will result in
check other clutch pressures.
approximately 0.19 kg/cm2 (2.7 psi) variation in the
9. Compare gauge readings with the following oil pressure.(Add shims to increases oil pressure;
chart. remove shims to decrease oil pressure.)
11. If a different shim pack is installed, repeat pres-
PRESSURE sure test to verify correct clutch pressure has
CLUTCH kg/cm² PSI been achieved.
H 16.5 ± 1.5 235 ± 20 12. If no further tests are to be performed, the shift
L 16.5 ± 1.5 235 ± 20 checker (if installed) may be removed.
4th 16.5 ± 1.5 235 ± 20 a. Disconnect harness connectors (5, Figure 2-
40) from chassis harness (6) and remove
3rd 20.5 ± 1.5 290 ± 20
shift checker.
R 30.5 ± 1.5 435 ± 20
b. Reconnect chassis harness connectors to
2nd 30.5 ± 1.5 435 ± 20 transmission control box (4).
1st 30.5 ± 1.5 435 ± 20 13. Be certain all pressure test port plugs are
installed. Install protective cover on transmis-
10. If pressure is outside normal range, the pres- sion control valve.
sure control valve spool shim pack (7, Figure 2-
39) must be increased or decreased.
Transmission Removal
FIGURE 2-43. ELECTRICAL WIRING
1. Park truck on a level surface, block wheels and 1. Electrical Connectors 2. Brake Cooling Valve
apply park brake. Raise dump body and install
body holding pins. Move hoist valve to FLOAT
position to put weight of dump body on pins.
Then lock the hoist lever in the hold position.
7. Tag and remove 6 pump outlet hoses (2, Figure FIGURE 2-45. HYDRAULIC LINES
2-45).
1. Housing 2. Hydraulic Hoses
FIGURE 2-48. STEERING AND HOIST PUMP FIGURE 2-51. FRONT TRANSMISSION MOUNT
1. Tube 2. Tube 1. Transmission Mount 2. Torque Converter
Procedure For Centering The Engine Assembly FIGURE 2-54. SHAFT ALIGNMENT
And Transmission Assembly 1. Engine End 3. Torque Converter
2. Tool End
Service
1. Remove drain plug (7, Figure 2-57) and drain
the oil from the filter housing. Tighten plug after
all oil is drained.
2. Unscrew filter bowl (4) from head assembly (1).
3. Remove the element and thoroughly clean and
dry all component parts.
4. Coat a new seal (9) with clean engine oil and
install.
5. Install a new element (5) and install the filter
bowl (4) into the head assembly (1).
6. Start the engine and let it idle for 5 minutes.
Stop engine and check for leaks. Check trans-
mission for proper oil level and adjust if neces-
sary.
Repair
Repairs to transmission cooler and wet disc brake
heat exchanger should be done by a qualified repair
facility
The wet disc brake heat exchanger is also mounted FIGURE 3-1.
below the radiator tank. Refer to Section C, Cooling
1. Screen\Magnet 4. Washer
System for removal and repair.
2. O-Ring 5. Capscrew
3. Cover
Installation
1. Install torque converter control valve and
tighten capscrews to 5 kg.m (36 ft. lbs.)
FIGURE 3-3. CONTROL VALVE MOUNTING
2. Connect tube (3, Figure 3-3).
1. Connector 3. Tube
3. Connect lockup solenoid valve wiring connector
2. Control Valve
(1).
4. Install cover (2, Figure 3-2) and hose (1).
Disassembly
1. Remove plate (1, Figure 3-4), then remove pis-
tons (2) and (4), spring (3), and torque con-
verter relief valve (5).
2. Remove cover (6), then remove spring (7).
3. Remove cover (8), then remove spring (9).
4. Remove plate (10), then remove pistons (11)
and (13), spring (12), and main relief valve (14).
5. Remove cover (15), then remove piston (16),
spring (17), and ring (18).
6. Remove cover (19), then remove pistons (20)
and (22), spring (21), and lockup valve (23).
DRIVELINES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F5-3
LUBRICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F5-4
FRONT DRIVELINE
Removal
1. Remove driveline protector if equipped.
2. Remove and tag any wiring or hoses which may
interfere with removal.
3. Attach a sling hoist to the driveline.
4. Remove the four capscrews at each spider
assembly and remove the driveline.
FIGURE 5-1. TYPICAL FRONT DRIVELINE
Installation INSTALLATION
Removal
1. Remove driveline protector if equipped.
2. Remove and tag any wiring or hoses which may
interfere with removal.
3. Attach a sling hoist to the driveline.
FIGURE 5-2. REAR DRIVELINE ASSEMBLY
4. Remove the four capscrews (6, Figure 5-2) at
(Typical)
each spider assembly, compress the splined
yoke and remove the driveline. 1. Spider Assembly 4. Seal Assembly
2. Capscrew 5. Grease Fitting
Installation 3. Slip Yoke 6. Capscrew
1. Position driveline between transmission and
differential input flange. Align the spider assem-
bly with the drive flanges and extend the
splined yoke until seated. Note: If either the stub, yoke, or seal is not
2. Clean the mounting capscrews (6, Figure 5-2) serviceable, parts must be replaced with a new,
to remove all traces of oil and dry thoroughly. balanced and matched set
Apply thread locker (LT-2) to capscrew threads.
Assembly
3. Install capscrews and tighten to 18 kg.m (130
ft. lbs.) torque. 1. Using clean and dry capscrews (2, Figure 5-2),
4. Install driveline protector if equipped. Tighten attach the spider assembly (1) at each end of
capscrews to standard torque. driveshaft. Tighten capscrews (2) to 21.5 kg.m
(155 ft. lbs.) torque. Note: Do Not use oil or
5. Install wiring or hoses removed to gain access adhesive on capscrew threads.
to driveline. Refer to “Lubrication” for greasing
instructions. 2. Install grease fittings (5) if removed. Lubricate
as specified below.
Disassembly
1. Remove the capscrews (2) and spider assem-
bly (1) from each end of driveline and inspect
LUBRICATION
for rough or frozen bearings.
Refer to Section P, Lubrication and Service for
Note: Do not disassemble the spider assembly. If
grease specification for truck operation over normal
bearings are unserviceable, replace the entire part
temperature ranges.
as a unit.
2. Clean all parts except the spider assembly in If truck is operating in extremely low temperatures
fresh solvent and blow dry with compressed air. (arctic conditions), grease driveline spider assembly
and splines using a lithium grease (GLT2-LI).
3. Inspect all parts for wear and damage. Com-
press and extend to check splines for excessive When greasing:
looseness or binding. Inspect spline grease
seal. • If equipped with multiple grease fittings on a
spider, apply lubricant through one fitting only.
• Add lubricant until traces of lubricant escape from
spider cap bearings and from shaft splines.
NOTE:
1. In the economy mode, the shift-up point from F1 to
F2 is 2000 rpm. The shift-down point from F2 to F1 is
1300 rpm.
2. In power mode, the shift-up point from F1 to F2, is
2100 rpm. The shift-down point from F2 to F1 is 1400
rpm.
Conditions: Range selector position: R FIGURE 6-6. GEAR SHIFTING TIME LAG
When the operator moves the lever (1, Figure 6-7) to The shift position is also displayed on the monitor
select the travel conditions, such as FORWARD or panel digital display.
REVERSE, an electrical signal is sent from a photo The lock button (1, Figure 6-8) must be pressed
interrupter (3, Figure 6-8) to the transmission shift when moving the range selector lever from “N” to “R”
controller. The lever position is displayed on the indi- or from “D” to “5”.
cator (3, Figure 6-7) (with night lighting) to the left of
the shift lever.
Adjustment Procedure
1. Disconnect wire connector (1, Figure 6-9), FIGURE 6-10. SPEED SENSOR ADJUSTMENT
release locknut (4), and remove sensor. 1. Sensor 3. Gear Tooth Tip
Observe location of gear teeth through sensor 2. Locknut 4. Clearance Gap
mounting hole. For proper adjustment, the tip of
a gear tooth must be aligned with the sensor
hole as shown in Figure 6-10. If necessary,
reposition gear.
2. Inspect sensor for iron particles or other foreign
material and clean if necessary.
3. Reinstall sensor. Adjust by hand until it just con-
tacts the gear tooth.
4. Turn counterclockwise 3/4 turn to obtain proper
clearance (“a”, Figure 6-10) and tighten locknut.
5. Reinstall wire connector.
The transmission oil temperature and torque con- 1. Be certain the sensor is allowed to reach ambi-
verter oil temperature sensors should be inspected ent temperature or warm it to a temperature
for physical damage and tested for adequate insula- listed on the graphs in Figure 6-12.
tion resistance and for proper thermistor resistance 2. Use a thermometer to determine the actual sen-
calibration. sor temperature.
3. Apply the ohmmeter leads to sensor pins #1 &
#2.
Insulation Resistance Test: 4. Read the resistance value shown on the meter
This test is performed to ensure the sensor and con- and compare the reading to the value specified
nector wiring provides adequate insulation from on the graph for the temperature of the sensor
ground and between the circuit conductors. The test (in degrees Farenheit or Celsius).
must be performed with an insulation tester. The test 5. If the reading does not fall within the minimum
equipment must be capable of applying 500 volts and maximum tolerance, replace with a new
DC. part.
Solenoid Valves
If visual inspection of the above items does not The table below lists the state of the transmission
reveal an apparent reason for the problems, refer to solenoid valves (or fill sensor) for each of the trans-
Section D, Hydraulic and Mechanical Systems Trou- mission range selector positions.
bleshooting for detailed troubleshooting procedures.
Transmission
Solenoid Valve
(Fill Sensor) H L R 1 2 3 4
R H L L H H H H
N H H H H H H H
Shift 1 H L H L H H H
Indicator 2 H L H H L H H
Speed 3 L H H H L H H
Range
Display 4 H L H H H L H
5 L H H H H L H
6 H L H H H H L
7 L H H H H H L
H = Open or 24 VDC
L = GND or 1.7 VDC
14 GND (pulse) 13
15 Brake Command 14
17 16
18
19
20
CONNECTOR: ATC4
PIN No. SIGNAL
1 RS422 TX (+)
2 RS422 RX (+)
3 RS232C TX
4 RS232C RX
5 RS485 (+)
6 S-NET (+)
7 RS422 TX (-)
8 FLASH switch
9 RS422 RX (-)
10 GND (serial)
11 RS485 (-)
12 S-NET (-)
The truck tires should be inspected and tire pressure • ALWAYS keep personnel away from a wheel
checked with an accurate pressure gauge before and tire assembly when it is being removed or
installed.
each working shift. Tire pressure will vary according
to manufacturer and local working conditions. Con- • DO NOT go near tires after brake fires until
sult the tire manufacturer for recommended tire pres- tires have cooled.
sure. • The tire and rim weigh approximately 2,800
Insure valve caps are securely installed on valve lbs. (1271 kg). BE CERTAIN tire handling
stems. The caps protect valves from dirt build up and equipment is capable of lifting and
damage. DO NOT bleed air from tires which are hot maneuvering the load.
due to operation; under such circumstances, it is nor- Manual tire removal and installation is possible but,
mal for pressure to increase due to expansion. due to the size and weight of the components, spe-
A bent or damaged rim which does not support the cial handling equipment such as a “tire handler” as
bead properly may cause abnormal strain on the tire shown in Figure 2-1 is desirable. Consult local tire
resulting in a malfunction. If a tire is cut, it should be vendors for sources of equipment designed espe-
removed and repaired. Neglected cuts cause many cially to remove, repair, and install large off-highway
tire problems. Water, sand, grit, dirt and other foreign truck tires.
materials work into a tire through a cut eventually
causing tread or ply separation.
Tires should be stored indoors, if possible. If stored
outdoors, cover tires with tarpaulin to keep out dirt,
water and other foreign materials. Long exposure to
the sun will cause ozone cracks. Storage should be
in a cool, dry, dark, draft free location. Tires should
be stored vertically. If they must be laid on their
sides, avoid distortion by stacking no more than three
tires on top of one another. Avoid contact with oil,
grease and other petroleum products.
Before storing used tires, clean thoroughly and
inspect for damage. Repair as necessary. When a
truck is placed in storage, it should be blocked to
remove the weight from the deflated tires. If a stored
truck cannot be blocked, check air pressure and
inspect tires twice a month for proper inflation.
1. Clamp Nut
1. Block the rear wheels on both the front and rear Each Brake Caliper weighs approximately 70 kg.
sides. (154 lbs.) The Wheel Hub Assembly weighs
approximately 568 kg (1252 lbs.). Use adequate
2. Refer to Front Tire and Rim Removal, this Sec- lifting devices when lifting these components.
tion, and remove front tire and rim assembly.
3. Disconnect and cap brake lines at brake cali-
pers (10). 4. Refer to Front Brake Caliper Removal, Section
J and remove the front caliper assembly.
5. Remove wheel cover (1, Figure 3-1).
6. Support or lift wheel hub with an adequate lifting
device.
Installation
1. Install new O-Rings (5, Figure 3-9) in bearing
(6).
FIGURE 4-3. SNAP RING ORIENTATION FIGURE 4-4. DIAGONAL PANHARD ROD
1. Link 2. Snap Ring 1. Bearing 5. Pin
2. O-Ring 6. Spacer
3. Panhard Rod 7. Snap Ring
4. Bushing
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . G5-4
Straight-away-travel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . G5-4
Turning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . G5-5
To Check Oil Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . G5-5
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . G5-5
3. Caliper assembly
a. Remove plate (1, Figure 5-9) on one side,
then remove caliper (3) together with pad
(2).
b. Remove plate on other side.
c. Remove brake disc (1, Figure 5-10).
ASSEMBLY of DIFFERENTIAL
Differential Bearing
1. Set differential case in tool (2, Figure 5-8). Tool
(2) consists of repair stand 790-501-2000 and
bracket 790-901-5110.
2. Using a push tool, press bearing (1, Figure 5-
27) in differential case (3), and install snap ring
(2).
No Gap
FIGURE 5-34.
1. Outer Race 3. Carrier
2. Outer Race
Input Pinion and Carrier Assembly 3. Heat bearing inner race* (1, Figure 5-36) to
100°C (212°F), then press onto pinion gear
When assembling the differential pinion carrier
shaft and install spacer (2).
assembly (Figure 5-33), if coupling bolts are not tight-
ened while the pinion bearing is turning, the bearing
will be damaged in a short period of operation.
FIGURE 5-36.
1. Bearing Inner Race 2. Spacer
FIGURE 5-38.
1. Cage Assembly
4. Set carrier (2, Figure 5-37) to pinion gear (3),
and install bearing (1).
7. Install oil seal (3, Figure 5-39) and O-ring (2) to
park brake support (1). Install support (1) to dif-
ferential case. Apply Three Bond thread tight-
ener TB1374 to mounting bolts and tighten to
56 ± 6 kg.m (405 ± 45 ft.lbs) torque.
FIGURE 5-37.
1. Bearing 3. Pinion Gear
2. Carrier
FIGURE 5-42.
FIGURE 5-41.
1. Spring Scale
The tooth contact pattern should Adjust the drive pinion by adjusting the shims at the
start from about 5 mm from the toe drive pinion cage. Adjust the driven gear in the
of the bevel gear and cover about same way as when adjusting backlash.
50% of the length of the tooth. It
should be in the center of the tooth
height.
1. Reduce shims at drive pin-
ion to bring closer to driven
gear.
Drive pinion is too far from driven 2. Move driven gear further
gear. away from drive pinion and
adjust backlash correctly.
Assembly
1. Install spacer (8, Figure 6-5) to carrier.
2. Install snap ring (3, Figure 6-7).
3. Fit spacer (2), and press fit outer race (1).
4. Set spacer (2, Figure 6-5) and bearing (1) in
position, then raise pinion gear and assemble,
and install bearing (1) from top.
5. Push pinion gear assembly (5) into carrier.
6. Fit plate (3) with capscrew (1) temporarily, then
install 2 guide capscrews to shaft (4), and press
fit.
NOTE: Expand fit the shaft, of press fit with a press.
1. Retainer 2. Capscrews
Inspection
1. If scratches or scores are found in housing or
on suspension rod, contact your Komatsu Dis-
tributor.
2. Discard seals, O-rings, wipers, stopper etc. and
replace with new parts during assembly.
Disassembly
1. Using appropriate blocking, stand the cylinder
assembly upright with housing end down.
Note: Place a container under suspension assembly
to catch oil released as suspension is disassembled.
Disassembly
1. Remove retaining ring from mounting eye of
housing or tube.
2. Remove bearing.
Inspection
1. Inspect spacers and mounting eye bearing
bores for damage. Inspect retainer ring
grooves. Repair or replace as necessary.
2. Inspect mount pin. Replace pin if worn or dam-
aged.
Assembly
1. Install retainer ring in groove.
2. Press spherical bearing in mount eye bore.
3. Install remaining retaining ring.
4. Refer to Suspension Installation.
5. Be sure grease is applied to bearing before
operating truck.
6. After suspension is installed on truck, it may be
necessary to charge suspension with nitrogen.
Refer to Suspension Oiling and Charging pro-
cedure, this section.
GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .H4-3
Equipment List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .H4-3
Equipment List
1. Service Kits:
a. EC6027 Oil Charging Kit (Figure 4-5)
b. EC3331 Nitrogen Charging Kit (Figure 4-6)
2. Jacks and/or Overhead Crane
3. Oil (MIL-L-2104C, SAE 10W)
4. Dry Nitrogen (See Nitrogen Specifications
Chart)
FIGURE 4-1. FRONT SUSPENSION HEIGHT
The operator of the truck applies the service brakes If air system pressure decreases below 3.2 kg/cm2
by use of a foot operated treadle valve in the cab. (45 psi), the emergency brakes apply automatically.
The brake circuit is an air controlled, hydraulically If air pressure continues to decrease, the parking
applied dry and wet disc system. brake will also apply.
During normal operation of the brake system Relay
Valve (RE-6), when the service brake pedal is
depressed, air is supplied from the air tank (dry) to COMPONENT DESCRIPTION
the pressure converters. The air pressure from the
air tank through the RE-6 valve should be equal to The main air system supplies air for actuation or
the air pressure from the service brake pedal. If a fail- release of all brake circuits. After the truck engine
ure of the air supply circuit or excessive air leakage has been started, pressurized air flows through the
from the (wet) air tank allows pressure to drop below wet air tank to the dry air tanks to the emergency
relay valves mounted near the tanks. As circuit pres-
3.2 kg/cm2 (45 psi), it will cause the RE-6 valve to go
sure increases, the RE-6 valve directs air to the pres-
into an “emergency mode”. This will apply the air
sure converters which apply the brakes while air
pressure stored in the (dry) air tanks (front and rear)
system pressure is building. The service brakes will
to the pressure converters.
remain applied until the pressure reaches approxi-
To control truck speed without use of the service mately 7.0 kg/cm2 (100 psi), at which point the
brakes, the operator may use the hand operated con- exhaust valve of the RE-6 valve will open and
trol valve lever to apply the rear wheel wet disc release the brakes.
brakes. This valve provides pressure to rear brakes
only to reduce truck speed. Use of only the rear
AIR TREADLE VALVE
brakes decreases the possibility of the truck skidding
on slippery roads. The brake circuit is controlled by a dual section trea-
dle valve located on the floor of the cab. When the
For full braking power in an EMERGENCY situation, brake pedal is depressed, air pressure within the two
the operator can manually apply the emergency sections of the brake valve is directed to two sepa-
brake. Located on the console next to the operator, rate brake circuits. One air circuit controls operation
the emergency brake control valve lever is to be of a brake circuit for actuation of the two brake actua-
used for emergency application of the wheel brakes tors, both front and one rear brake assemblies. The
in an EMERGENCY ONLY. DO NOT use the emer- other circuit actuates the other two brake actuators. If
gency brake valve to stop the truck during normal one brake circuit should malfunction, the other circuit
operation! is still available to apply the brakes. The flow of air
The parking brake toggle lever, mounted on the con- from each section of the dual brake valve passes
sole next to the operator, enables the operator to through a valve located in each circuit and then to the
apply and release the parking brake. The parking emergency relay valves (RE-6) mounted on the front
brake is spring applied and air released. It should be and rear dry tanks. The emergency relay valves reg-
used when parking the truck in a designated parking ulate pressure from the dry air tanks to be applied to
area. the pressure converters.
The Front Brake OFF switch changes the braking
action of the system for operation under various road
surface conditions. The switch is located on the
instrument panel to the left of the steering wheel.
When the switch is in the OFF position (dry road con-
ditions), brake pressure is applied to both front and
rear wheels. If the switch is depressed to the ON
position (slippery road conditions), brake pressure is
applied only to the rear wheels. The pilot light inside
the switch is illuminated in this position.
FIGURE 2-6. BRAKES APPLIED - VALVE FIGURE 2-5. BRAKE PEDAL APPLICATION
BALANCED
When air pressure below the relay piston is equal to
the air pressure above it, the relay piston and emer-
gency piston will lift slightly and the inlet area of the
inlet and exhaust valve will close. The valve is then in
a balanced condition
NOTE: The brakes are not necessarily fully applied
when the valve is in a balanced position, but are
applied only to the extent of pressure applied by the
operator at the brake treadle valve. Should the
operator continue to depress the brake pedal,
additional air pressure will open the inlet passage in
the RE-6 valve. Again the balanced condition will
occur if the operator stops and retains the brake
pedal in one position.
Releasing
When the operator releases the brake pedal, air in FIGURE 2-6. BRAKES APPLIED - VALVE
the service port line is exhausted through the BALANCED
exhaust port of the service brake valve. Upward
movement of the relay piston unseats the exhaust
portion of the inlet and exhaust valve and air in the
pressure converter is exhausted through the RE-6
valves releasing the brakes.
FIGURE 2-11.
FIGURE 2-12.
1. Piston
2. Valve Body
3. Seat
4. Seat
A. To Atmosphere
B. From Emergency Brake Circuit
C. To Parking Brake Relay Valve
D. From Rear Air Tank
FIGURE 2-18. PARK BRAKE RELEASE FIGURE 2-19. PARK BRAKE APPLIED
1. Exhaust Valve Seat D. To Parking Brake 4. Relay Piston D. To Parking Brake
2. Valve Chamber Chamber
A. From Parking Brake E. From Air Tank A. From Parking Brake E. From Air Tank
Pilot Valve F. From Parking Brake Pilot Valve F. To Parking Brake
C. Exhaust Port Pilot Valve B. Chamber Pilot Valve
C. Exhaust Port
Specifications:
• Normally closed switch, opens at 75 psi.
• Measuring between pins 1 and 2 at:
8.3 kg/cm2 (120 psi) - 160 ohms or less
5.2 kg/cm2 (75 psi) - 640 - 800 ohms
Specifications:
Service brake switch
• Measuring between pins 1 and 2
above 0.6 kg/cm2 (8 psi) continuity
below 0.2 kg/cm2 (3 psi) no continuity
Specifications:
Normally open switch: closes at 5.2 kg/cm2 (75 psi), FIGURE 2-28. PARKING BRAKE SWITCH
opens at 4.2 kg/cm2 (60 psi). 1. Port 3. Cover
2. Diaphragm 4. Connector
• Measuring between pins 1 and 2
above 5.7 kg/cm2 (80 psi) continuity
below 3.7 kg/cm2 (53 psi) no continuity
Specifications:
Normally closed switch, actuates at 2500 ± 10 RPM.
Opens and releases retarder at 2350 ± 10 RPM.
• Measuring between pins 1 and 2, 20-60 ohms.
Specifications:
• Measuring between pins 1 and 2, 20-60 ohms.
Function
Function
When the lever is fully forward (unlocked position),
the emergency brake is released and in the correct
position for normal truck operation. Moving the lever
to the rear (locked position) provides a modulated
control to vary emergency brake application from
fully released to fully applied.
Figure 2-35 shows the emergency brake control
valve output pressure, with tank pressure at 8 kg/cm2
(114 psi) in relation to the amount of handle rotation; FIGURE 2-36. VALVE CROSS SECTION
between the full on position (0°) and full off position
(55°). 1. Handle 7. Valve Spring
2. Cam Ring 8. Main Spring
3. Head 9. Feed Valve
4. Body 10. Feed Valve Seat
5. Piston 11. Return Spring
6. Cover 12. Exhaust Valve Seat
A: Outlet Port (to RE6 valves)
B: Inlet Port (from air tank)
C: Exhaust Port
FIGURE 2-37.
9. Feed Valve A. Exhaust Air
B. From Air Tank
C. From RE-6 Valve
FIGURE 2-38.
9. Feed Valve A. Exhaust Air
12. Exhaust Valve Seat B. From Air Tank
C. From RE-6 Valve
FIGURE 2-39.
5. Piston A. Exhaust Air
8. Main Spring B. From Air Tank
9. Feed Valve C. From RE-6 Valve
12. Exhaust Valve Seat
FIGURE 2-40.
5. Piston A. Exhaust Air
6. Cover B. From Air Tank
9. Feed Valve C. From RE-6 Valve
FIGURE 2-41.
9. Feed Valve A. Exhaust Air
11. Return Spring B. From Air Tank
12. Exhaust Valve Seat C. From RE-6 Valve
1. Plunger 7. Upper valve (upper inlet valve) 13. Lower valve return spring
2. Seat 8. Outer relay piston 14. Relay piston return spring
3. Pedal 9. Lower valve (lower inlet valve) 15. Upper ring retainer
4. Piston 10. Cover 16. Upper valve return spring
5. Stop bolt 11. Lower valve guide 17. Valve body
6. Piston return spring 12. Check valve 18. Rubber Spring
A. When brake pedal is being depressed. If the upper inlet valve (7) is opened, the pressur-
ized air will flow to the relay piston (8) through pas-
When the brake pedal (3, Figure 2-43) is depressed, sage (F), pushing inner relay piston (8) downward,
the pedal movement will be transmitted to the piston which, in turn, will open the lower inlet valve (9).
(4) through the rubber spring (18), causing the pis-
ton (4) to move downward. Then, the exhaust port Then, pressurized air from the air tank will flow to
(E) will be closed and the upper inlet valve (7) will the front brake relay valve to start applying the front
be opened. Thus, the pressurized air from the air brake.
reservoir (tank) will flow to the rear brake chamber, Actually, the force required to move the relay piston
causing the application of the rear brake to start. (8) is very small and, therefore, there is little differ-
ence in timing for the upper and lower inlet valves to
begin opening.
Removal
NOTE: Before disassembling, make match marks at
all joints to act as a guide when reassembling.
Installation
NOTE: When installing the brake chamber assembly,
be certain that the spacers support the chamber
away from the mounting plate. If the chamber is
FIGURE 3-12. OIL CYLINDER
installed touching the mounting plate, the chamber
may crack when the mounting capscrews are 1. Capscrews 2. Oil Cylinder
tightened.
Oil cylinder
Cover assembly 1. Install oil cylinder (2, Figure 3-12) to air cylinder
1. Install plug (6, Figure 3-18) with Three Bond assembly.
(TB2411) adhesive and tighten to 2.0 kg.m (14 2. Tighten capscrews (1) to 3.85 kg.m (28 ft. lbs.)
ft.lbs.) torque. torque.
2. Install filter (9) and snap ring (8).
3. Assemble bushing (7), secondary cup (2, Fig-
ure 3-17 or 3-18), spacer (4), secondary cup Checking
(2), cup support (1) and stop ring (5) in order. 1. Bleed air from oil cylinder.
2. Check that at least 180 kg/cm2 (1680 psi) of oil
pressure is generated in the oil cylinder when 8
Air cylinder assembly
kg/cm2 (114 psi) of air pressure is applied to air
1. Install packing (15, Figure 3-13) to piston and cylinder.
rod assembly (3).
3. Check that there is no leakage of air or oil.
DIMENSION “C”
Standard Size Tolerance Standard Clearance
Piston Housing Clearance Limit
Clearance between 80 mm
Cylinder Housing -0.030 to -0.076 mm +0.074 mm 0.03 - 0.15 mm 0.25 mm
(3.15 in.) (-0.001 to -0.003 in.) (+0.003 in.) (0.001 - 0.006 in.) (0.098 in.)
and Piston
TORQUE VALUES
6B. Tighten to 6.0 ± 0.5 kgm (45 ± 4 ft. lbs.) torque.
15. Tighten to 17.5 ± 1.5 kgm (127 ± 10 ft. lbs.) torque.
Inspection
Remove all O-Rings and discard. Thoroughly clean
parts and inspect valve body for cracks, scoring, and
port thread damage. Replace any part if damage or
excessive wear is evident. All O-ring seals, the feed
valve, and exhaust valve seat should be replaced
during rebuild. Refer to the appropriate parts book for
these parts in a pre-packaged kit.
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . J4-6
The pad wear may not be the same for both left 1. Brake Pad 2. Wear Limit Line
and right wheels, so check the wear of all pads.
If any pad is worn beyond the limits stated
above, replace all pads (both left and right
sides).
Refer to Front Brakes Section for specific
repair, disassembly, or replacement procedures
for the front brake assembly.
Start the engine and wait for the air gauge to enter
the green range, then bleed the air from the circuit as
follows.
Rear Brakes
1. Bleed the air at the slack adjuster end first.
Depress the brake pedal, then loosen air bleed
plugs (1 or 2, Figure 4-5) 3/4 turns. Tighten the
plug again, then release the pedal.
FIGURE 4-5. SLACK ADJUSTER
2. Continue this procedure until no more bubbles
come out from the air bleed plug hole, then 1. Air Bleed Plug 2. Air Bleed Plug
bleed the air from the wheel plug (1, Figure 4-
6).
3. Continue this procedure until no more bubbles
come out from the air bleed plug.
4. After bleeding the air, close the plug and fit the
cap.
Front Brakes
1. The oil tank is separately installed, so always
check the oil level while bleeding the air to avoid
running out of oil.
2. Depress the brake pedal, then loosen air bleed
plug (1, Figure 4-7) 3/4 turn. Tighten the plug
again, then release the pedal.
3. Continue this procedure until no more bubbles
come out from the air bleed plug.
Installation
1. Install brake pads.
2. Install pin (1, Figure 5-1) and tighten capscrew
(2) to 5.25 ± 0.25 kg.m (38 ± 2 ft. lbs.) torque.
3. Bleed the air from the brake circuit. Refer to
Brake Bleeding this Section.
Disassembly
1. Loosen capscrews (1, Figure 5-5) and (2),
remove pins (3), (4), and (5), the remove pads
(6).
2. Remove plate (7), then remove plug (8), backup
ring (9), and seal (10).
3. Remove dust seal (11), then remove piston
(12).
4. Disassemble the other pistons in the same way.
TIGHTENING TORQUES
2. 94.5 ± 10 kg.m (685 ± 72 ft. lbs.) torque.
3. 94.5 ± 10 kg.m (685 ± 72 ft. lbs.) torque.
4. 21.0 ± 1 kg.m (150 ± 7 ft. lbs.) torque.
5. 2.6 ± 0.3 kg.m (20 ± 2 ft. lbs.) torque.
Installation
Driveshaft Removal
1. Remove guard (1, Figure 7-13) and cover (2).
BRAKE RELEASE
FIGURE 7-15. PARK BRAKE INSPECTION Releasing Parking Brake And Emergency Brake
1. Brake Pads 3. Capscrew After Being Actuated In An Emergency
2. Brake Caliper 4. Brake Disc If the pressure inside the air tank drops abnormally
due to some problem, such as leakage of air from the
PARKING BRAKE INSPECTION air circuit, the parking brake and emergency brake
ITEM NEW LIMIT REMEDY are automatically actuated.
“a” - Pad
(Includes Plate 21.5 mm 11.5 mm Replace Release Of Parking Brake
Thickness) (0.847 in) (0.45 in) Each parking brake caliper is individually applied and
“b” - Disc 25 mm 20 mm Replace released through separate air chamber actuators
Thickness (0.99 in) (0.79 in) (spring cylinder assemblies). If the parking brake can
Disc Face 0.4 mm 0.8 mm Replace not be released after its emergency application -
Runout (0.016 in) (0.032 in) even if the parking brake valve lever is put in
RELEASE position - take the following actions to
NOTE: The brake disc can be machined and reused
release the parking brake:
as long as it is not less than 20 mm (0.79 in) thick
after machining. 1. Block disabled truck to prevent movement and
confirm safety in the surrounding area.
2. At parking brake relay valve, remove both air
hoses (4, Figure 7-16) connected to the air
chambers of the parking brake spring cylinder
assemblies (5).
3. Connect these hoses together using a “tee” fit-
ting with compatible thread ends.
4. Connect third connector of “tee” to a hose from
an air supply of sufficient capacity to release
Parking Brake Disc Installation calipers. Apply air and release brake.
1. Install lifting sling securely around brake disc (4, 5. With parking brake released, turn adjustment
Figure 7-14) and move disc into position. bolt (2) counterclockwise, and check for ©playª
in linkage (3). Remove pin (1). Repeat for other
2. Install capscrews (1) holding park brake disc.
caliper. Disconnect air supply.
Tighten capscrews to 56 ± 6 kg.m (400 ± 40
ft.lbs.) torque.
If the air system is not operating, the service 1. After making preparations to tow the machine,
brakes will not apply; this is very dangerous. Be pull rings (2, Figure 7-17) on the 4 drain valves
sure to tow the truck at low speed, keeping the on the front air tanks to release the air pressure.
engine running (if possible) and always be ready 2. After exhausting all air pressure, release rings
to steer. (2).
Refer to Parking Brake Inspection and Adjustment, 3. Drain the rear air tank by pulling and holding the
for instructions for reconnecting and adjusting park ring on the air drain valve mounted on the frame
brake. in front of the right rear suspension. Keep drain
valve open until all air is exhausted from tank.
This will allow the emergency brake to release.
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .K2-4
Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .K2-8
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .K2-8
Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .K2-8
Stand-by Mode
When the air system drops to the primary governor
regulated “cut-in” pressure, 7.6 kg/cm2 (108 psi), the
air dryer unloader valve (3) closes as the unloader
line pressure evacuates through the exhaust port X
of the governor. The compressor is signaled to load
and resume pumping.
FIGURE 2-2. AIR DRYER DIAGRAM
Secondary Governor
COMPONENTS PORTS
1. Air Dryer A: Outlet/Check Valve The secondary governor will not signal the compres-
2. Purge Tank B: Inlet Port sor to unload during normal operation. However, if a
3. Wet Tank C: Unloader Port blockage occurs in the line between the expansion
4. Secondary Governor D: Purge Tank Port tank, air dryers, and the wet tank, such as an air
5. Air Compressor E: Dryer Exhaust dryer element that needs to be replaced, expansion
6. Expansion Tank F: Governor Inlet Port tank pressure may increase to 9.0 kg/cm2 (128 psi)
7. Primary Governor G: Compressor Air Inlet and the secondary governor will provide the signal to
X: Governor Exhaust turn the compressor off.
COMPONENTS PORTS
1. Purge Tank 9. Shuttle Valve A. Check Valve E. Dryer Exhaust
2. Bleed Valve 10. Wet Tank B. Dryer Intake F. Governor Air Supply
3. Unloader Valve 11. Rear Brake Tank C. Unloader G. Compressor Air Intake
4. Air Governor, Primary 12. Dry Tank D. Purge Tank X. Governor Exhaust
5. Turbo Valve 13. Pilot Tank
6. Air Governor, Secondary 14. Air Dryer
7. Expansion Tank 15. Check Valve
8. Air Compressor
VALVES OPEN - Check Valve, Bleed Valve, Turbo Valve
VALVES CLOSED - Ball Check Valve, Unloader Valve
COMPONENTS PORTS
1. Purge Tank 9. Shuttle Valve A. Check Valve E. Dryer Exhaust
2. Bleed Valve 10. Wet Tank B. Dryer Intake F. Governor Air Supply
3. Unloader Valve 11. Rear Brake Tank C. Unloader G. Compressor Air Intake
4. Air Governor, Primary 12. Dry Tank D. Purge Tank X. Governor Exhaust
5. Turbo Valve 13. Pilot Tank
6. Air Governor, Secondary 14. Air Dryer
7. Expansion Tank 15. Check Valve
8. Air Compressor
VALVES OPEN - Ball Check Valve, Unloader Valve
VALVES CLOSED - Check Valve, Bleed Valve, Turbo Valve
Operation
Refer to Figure 2-7.
As air pressure builds in the wet tank, the diaphragm
(4, Figure 2-7) will be pushed down allowing contam-
inants and moisture in the bottom of the tank to accu-
mulate in chamber “A”.
When air pressure in the wet tank decreases, the
diaphragm will move upwards allowing the debris to
be expelled through the drain port in the bottom of FIGURE 2-8. HORN SOLENOID
the valve body.
1. Coil Assembly 4. Filter
2. Core 5. Terminal
3. Plunger
Removal
1. Drain the air system
2. Disconnect heater wiring.
• The truck's wheels must be chocked. Block 3. Mark the air lines for later reference and discon-
the wheels and make sure the vehicle will not nect from air dryer(s).
roll, before releasing the brakes and before
4. Remove the lock nuts, washers, and capscrews
performing any test and/or isolating any air
system component. that attach the air dryer to the mounting bracket.
Symptoms / Actions
1. Regular service interval.
1 year / 5000 Hours
NOTE: The above is a guideline only. Check the
tank(s) on regular basis. If moisture exists, replace
cartridge.
2. Water in tanks.
Desiccant cartridge requires regular servicing at
intervals determined by compressor duty cycle
or type of operation, environment, etc.
COMPONENTS PORTS
1. Desiccant Cartridge A. Check Valve
2. Check Valve B. Intake
3. Check Valve Nut C. Unloader
4. Body Gasket D. Purge Tank
5. Ball Check Valve E. Exhaust
6. Bottom Cap Assy.
7. Turbo Valve
8. Seal Retainer
9. Unloader Valve
10. Heater
11. Safety Valve
12. Bleed Valve Nut
Pressure slow or no build: If the air dryer exhaust port and unloader valve
exhaust port do not align, air dryer will not
1. Start engine and build pressure to just before unload.
"cut-out".
11. Install retainer.
2. Stop engine. Apply soap solution at exhaust
port or listen for air leak at exhaust port. 12. Apply a light coating of grease on the threads of
the two retainer bolts.
3. If a leak is present, replace unloader valve.
13. Install the two retainer bolts and tighten to 13.56
- 20.34 N.m (10 - 15 ft. lb.) torque.
Compressor cycles rapidly: 14. Reconnect the unloader air line to air dryer
1. Remove governor line from UNL port on air unloader port.
dryer.
2. Start engine and build to "cut-out" pressure.
3. Stop engine. If no air leaks are present, replace
unloader valve.
1. Start engine and build air pressure allowing NOTE: The above symptoms could also lead to turbo
dryer to exhaust. valve replacement. A malfunctioning turbo valve will
tend to allow pressure to drop to "cut-in" pressure
2. Stop engine.
within seconds.
3. After initial exhaust, air should bleed with
decreasing intensity out the exhaust port for Operational Check
approximately 45 seconds.
1. Disconnect line at purge port and plug.
4. If air fails to bleed as described, replace bleed
2. Start engine and build pressure to "cut-out"
valve kit.
pressure. Stop engine.
3. Apply soapy solution around exhaust port.
Bleed Valve Replacement 4. If soap bubbles exist, replace check valve.
Symptom Symptom
Dryer frequently unloads. Dryer won't exhaust.
Air continually flows from exhaust port when Exhaust port leaks.
compressor is in standby mode.
Cannot build pressure.
System pressure drops very rapidly.
Operational Checks
NOTE: The above symptoms could also lead to
check valve replacement. A malfunctioning turbo Thermostat must be cooled to at least 2°C (35°) F to
valve will tend to allow pressure to drop to cut-in check.
pressure within seconds. 1. Connect an ohmmeter across the heater electri-
cal terminals. Ohmmeter should show continu-
Operational Check:
ity.
1. Disconnect line at purge port and plug. 2. If the reading shows an open circuit, replace
2. Start engine and build pressure to "cut-out" heater assembly.
pressure. Stop engine.
3. Apply soapy solution around exhaust port. Heater Assembly Replacement
4. If soap bubbles exist, replace turbo valve. 1. Disconnect heater leads.
2. Remove the two screws from heater cover.
Turbo Valve Replacement
3. Remove heater/thermostat assembly (10, Fig-
1. Drain the air system. ure 3-1) and discard.
2. Disconnect the heater wiring. Disconnect the 4. Thoroughly clean entire area.
inlet and unloader lines from their respective 5. Apply a light coating of anti-seize to the heater
ports. Mark lines for later assembly. element and to the thermostat cavity only. Do
3. Remove eight bolts from bottom cap and set not apply this compound to screws.
aside. Discard gasket. 6. Install new heater. Twist slightly to spread anti-
4. Remove turbo nut, valve stop, and valve (7, Fig- seize. Install new set screw until snug. Set
ure 3-1) and discard. screw will protrude from bottom cap about
5. Clean cavity area thoroughly. 0.125 inch (3.18 mm).
DO NOT OVER-TIGHTEN.
6. Lightly coat the two small O-ring surfaces and
install on piston. Carefully install valve in cavity 7. Install new thermostat. Coil wires around heater
with tapered side up. cover posts allowing wires to protrude through
slots. Place the two # 6-32 x 1.125 inches (2.86
7. Place valve stop on top of valve concave side
cm) screws in heater cover and attach the ther-
down.
mostat.
8. Lightly lube large O-ring and place on nut.
8. Fill heater cover with non-corrosive RTV.
Install flat seal into nut.
9. Connect blue heater wire to a good chassis
9. Install nut and tighten to 68 N.m (50 ft. lb.)
ground.
torque.
10. Connect orange wire to ignition switch.
10. Place gasket on bottom cap aligning small hole
with small check valve. Locate bottom cap so 11. Seal and route heater wires carefully.
that inlet port is directly below outlet port. Install
the eight bolts set aside during disassembly and
tighten to 20 -27 N.m (15-20 ft. lb.) torque.
11. Re-connect inlet and unloader lines as previ-
ously marked to air dryer.
12. Re-connect heater wiring.
Problem: The air compressor goes into the standby mode but cycles rapidly.
Fittings are loose or damaged. Tighten and/or replace as necessary.
Air reservoir, tubing, or hoses are damaged. Repair or replace as necessary.
The air dryer check valve is worn. Clean cavity. Replace check valve assembly.
Turbo valve is worn. Clean cavity. Replace turbo valve assembly.
Air governor malfunctioning. Replace governor valve.
The air dryer unloader valve seal is worn. Clean cavity. Replace the unloader valve assembly.
Problem: Air flows from the exhaust port when the air compressor is trying to build up pressure.
The unloader valve is worn. Clean cavity. Replace the unloader valve assembly.
Dirt/foreign material is stuck in the unloader valve. Clean cavity. Replace the unloader valve assembly.
Air governor malfunctioning. Replace governor valve.
Heater assembly malfunctioning. 0°C (32°F) Replace heater assembly.
Problem: The air compressor runs continuously (system pressure will not build).
Fittings are loose or damaged. Tighten or replace loose or damaged fittings.
Air reservoir, tubing, or hoses are damaged. Repair or replace damaged items.
The air compressor needs to be serviced or Rebuild or replace the air compressor.
replaced.
The air dryer unloader valve is worn. Clean cavity. Replace the unloader valve assembly.
Line between governor and air compressor is Replace the line or remove the blockage.
blocked.
Air governor malfunctioning. Replace governor valve.
Problem: The air dryer does not unload when the air compressor goes into standby mode.
The line between the air governor and the air dryer Repair or replace the air line, or tighten the fittings.
unloader port is damaged or leaking.
The unloader valve is worn. Clean cavity. Replace the unloader valve assembly.
Ice has formed in the unloader valve. Check heater assembly; replace if necessary.
The heater is malfunctioning. Check heater assembly; replace if necessary.
The unloader valve sleeve is misaligned. Remove and repair dryer.
1. Connect an air supply of 130 psi (9.1 kg/cm2) After adjustment, apply Loctite to bottom of
locknut (10) and thread onto adjusting screw.
through an adjustable pressure regulator to the
Hold adjusting screw (11) and tighten locknut
governor supply port (stamped "RES"). (10).
2. Install a 0-200 psi (14 kg/cm2) pressure gauge
in the unloader port (stamped "UNL").
7. After pressure has been verified, reinstall rub-
3. Remove the rubber cover (17, Figure 3-4) ber cover (17).
located on top of the governor. Loosen the lock-
nut (10) located on the adjusting screw (11).
4. Turn on the air supply and slowly increase the
regulator pressure until a sudden pressure jump
occurs on the gauge and read the pressure.
(This is the current "cut-out" pressure setting.)
5. While observing the gauge, decrease the regu-
lator pressure until the gauge drops to 0 psi.
(The pressure reading before dropping to zero
is the current "cut-in" pressure.)
6. Adjust the governor for the correct "cut-out"
pressure by rotating the adjustment screw (11)
clockwise to decrease the pressure or counter-
clockwise to increase the "cut-out" pressure to
the specifications below:
Note: One turn of the adjusting screw changes the
pressure settings approximately 1.1 kg/cm2 (16 psi).
Primary Governor
Removal 4. Start the truck and allow the air pressure to rise
to full pressure.
5. Attach a hanging scale to the handle assembly
lever (21).
Relieve air pressure from the system before 6. With supply air pressure at 740 kPa (107.32
working with or on the retarder valve/lever psi), to maintain minimum lever force of 2.9~4.9
assembly. Failure to do so could result in bodily N (0.3~0.5 kgf) to move lever to 190 mm (0.75
harm and/or damage to the interior of the cab. in.) from center when releasing air pressure,
turn case (17, Figure 5-1) to tighten or loosen
tension on spring (18) and secure with nut (16).
1. Shut the engine down and turn off the key
Tighten nut to 9.8~14.7 N.m (7.23~10.85 ft.
switch.
lbs.) torque.
2. After air pressure has been relieved from the
system, disconnect the three air hoses from the
ports in the bottom of the retarder valve body NOTE: DO NOT turn the case inward more than four
(Figure 5-1). Mark the hoses to indicate their turns after initial contact between case (17), spring
appropriate ports for future reference at installa- (18), and plunger (19) is made.
tion.
3. Remove the two bolts (3, Figure 5-2) and lock-
washers (4) from the clamp (5). Separate the
clamp from the body and remove the spacer
(2). Remove the retarder valve/lever assembly
from the steering column.
Installation
1. Hold the clamping area of the retarder valve
body (1, Figure 5-2) against the steering column
so that the lever extends to the right of the col-
umn.
2. Install clamp (5) opposite the valve body around
the steering column and install bolts (3) and
lockwashers (4).
3. Connect the three air hoses to the appropriate
ports in the bottom of the retarder valve body FIGURE 5-1. PORTS
(Figure 5-1).
1. Supply 3. Delivery
NOTE: If the lever replacement kit has been 2. Exhaust
installed, it may be necessary to adjust the lever
friction after installation. If adjustment is required,
proceed with the following steps.
Raise the dump body and lock with the safety pin
prior to working on components.
Removal
1. Remove tubes (1 & 2, Figure 3-2). Cap tubes
and pump ports.
2. Remove hoses (1 & 2, Figure 3-3). Cap hoses
and pump ports.
3. Remove hydraulic pump assembly (3, Figure 3-
2).
FIGURE 3-1. HYDRAULIC PUMP PIPING
1. Pump Inlet Tube 3. Hydraulic Pump
2. Pump Inlet Tube
HYDRAULIC TANK
Filling instructions (hoist oil supply) FIGURE 3-3. HYDRAULIC PUMP
1. Outlet Hose 3. Hydraulic Pump
1. Lower the dump body and shut down the
2. Outlet Hose
engine.
Cleaning
Release hydraulic tank filler cap slowly to
1. With the brake cooling oil drained, remove the remove any internal pressure.
flange capscrews (3, Figure 3-7).
Hydraulic fluid escaping under pressure can
2. Disassemble the tube coupling forward of the have sufficient force to enter a person's body by
strainer or remove the flange capscrews at the penetrating the skin and cause serious injury and
oil cooler inlet and remove tube (4). possibly death if proper medical treatment by a
3. Remove strainer (1) and clean thoroughly. physician familiar with this injury is not received
Inspect wire mesh for damage. immediately.
4. Reinstall strainer and tube using new O-ring
seals.
5. Refer to Filling Instructions in this Section.
The oil from the pump passes through the demand The oil from the steering pump enters port (A, Figure
valve and enters port P of the steering valve. 4-5). At the same time, the oil from the hoist pump
enters port B. When the steering valve is at neutral,
Valve spool is at the neutral position, so port P and port P of the steering valve is closed, so the pressure
ports (RT and LT) to the cylinder are closed. No oil at port P rises. The pressure from port P passes
flows to the cylinder, so the cylinder does not move. through orifice F enters the chamber C, and moves
At the same time, port LS is connected through port spool (7) to the right.
R to the tank. As a result, there is no oil pressure at Port LS and chamber D are connected to the tank,
port LS, so all the oil from the pump at the demand and the force moving spool (7) to the left is the force
valve flows to the hoist valve. of spool return spring (6). The pressure in chamber C
rises until it overcomes the set pressure of spool
return spring (6). As a result, spool (7) stops in the
position shown in the diagram, and all the oil from the
steering pump and hoist pump flows to the hoist
valve.
When the steering wheel is turned slowly to the right The area of the opening of the steering valve orifice
(Figure 4-6), input shaft rotates. When this happens, is small, so the difference in pressure between the
valve spool moves down. So when input shaft two sides of the orifice is large. As a result, the move-
rotates, the oil from the demand valve flows into port ment when the steering wheel is operated slowly to
P. the right, the spool moves a short distance to the left,
and some of the oil from the steering pump flows to
The oil inside the valve spool then passes between
the steering valve. The remaining oil from the steer-
the stator and rotor in the metering portion of spool
ing pump and all the oil from the hoist pump flows to
valve.
the hoist valve.
After the amount of oil flowing to the steering cylinder
is measured here, it enters the inside of the valve
spool, passes through a hole in the valve spool
through port RT and flows to the steering cylinders.
In this way, the two cylinders are actuated and the
wheels turn to the right.
The oil returning from the steering cylinder flows from
port LT and goes back to the tank.
The demand spool is actuated by the difference in
pressure between the oil pressure at port P end and
the oil pressure at the port LS end. As a result, only
the necessary amount of oil flows to the steering cir-
cuit, and remaining oil flows from the demand valve
to the hoist valve.
When the steering wheel is turned quickly to the left The area of the opening of the steering valve orifice
(Figure 4-7), input shaft rotates. When this happens, is large, so the difference in pressure between the
valve spool moves up. The oil from the demand valve two sides of the orifice is small, therefor the differ-
flows into port P, through a hole in the valve spool, ence at chamber C and D is also small. As a result,
and enters the inside of the valve spool. spring (6) moves spool (7) a long distance to the left,
and all the oil from the steering pump together with
The oil inside the valve spool then passes between
some of the oil from the hoist pump passes through
the stator and rotor in the metering portion of the
check valve (2) and flows to the steering valve to pro-
valve.
vide a large amount of oil to the steering valve.
After the amount of oil flowing to the steering cylinder
is measured here, it flows through port LT and flows
to the steering cylinders.
In this way, two cylinders are actuated and the
wheels turn to the left.
The oil returning from the steering cylinder flows from
port RT and goes back to the tank.
The demand spool is actuated by the difference in
pressure between the oil pressure at port P end and
the oil pressure at the port LS end. As a result, only
the necessary amount of oil flows to the steering cir-
cuit, and remaining oil flows from the demand valve
to the hoist circuit.
Flow Switch
The flow switch (Figure 4-10) is installed in the steer-
ing circuit piping to monitor steering circuit oil flow.
Operation
Refer to “A”, Figure 4-10:
When oil is flowing in the pipe, plate (4) is pushed to
the left, overcoming spring (3) force and the lever
pivots on pin (2). The magnet (5) mounted on the
lever moves away from the reed switch and opens
the contact.
Refer to “B”, Figure 4-10:
When oil flow is interrupted, the lever pivots in the
opposite direction due to spring (3). Magnet (5)
moves close to the reed switch contacts closing the
electrical circuit. This electrical signal is routed to the
relay timer below.
Relay Timer
The relay timer provides an electrical delay in the cir-
cuit between the flow switch and the emergency
steering pump motor relay. The timer is adjusted to
provide a 1.5 second delay to prevent accidental
actuation of the emergency steering system due to
slight interruptions in oil flow. Refer to Figure 4-12 for FIGURE 4-11. RELAY TIMER
electrical schematic.
1. Timer Assembly 2. Delay Adjustment
Knob
FIGURE 5-2.
FIGURE 5-1.
1. Yoke 3. Capscrews
1. Lock Bolt 3. Steering Valve Assy.
2. Steering Valve Assy. 4. Mounting Bracket
2. Hoses 4. Column Shaft
FIGURE 5-5.
1. Pin 2. Washer
FIGURE 5-11.
1. Rod 3. Rod
2. Roller 4. Spring
FIGURE 5-13.
FIGURE 5-15.
1. Snap Ring 4. Seal Ring
2. Spacer 5. Upper Cover
3. Seal
12. Remove seal (6, Figure 5-15) and snap ring (1),
then remove spacer (2), seal (3), and seal ring
(4) from upper cover (5).
NOTE: Seal (3) and seal ring (4) may be combined
into one piece.
13. Remove snap ring (1, Figure 5-16), thrust
washer (2), thrust bearing (3), thrust washer (4),
and wave washer (5) from input shaft (6).
14. Using a punch (1, Figure 5-17) 3.0 mm dia., x
16 mm long (0.12 in. dia. x 0.62 in. long), FIGURE 5-18. PIN DETAIL
remove pin (2, Figure 5-18) from input shaft.
1. Shaft 2. Pin
NOTE: To prevent damaging the input shaft, carry
out the operation on a wooden block.
FIGURE 5-23.
1. Thrust Washer 3. Input Shaft FIGURE 5-26. BALL INSTALLATION
2. Thrust Bearing
1. Ball 2. Valve Spool
FIGURE 5-24.
1. Thrust Washer 2. Snap Ring FIGURE 5-27. INPUT SHAFT INSTALLATION
FIGURE 5-29.
FIGURE 5-35.
FIGURE 5-43.
1. Ball 4. Roller
2. Rod 5. Rod
3. Spring 6. Valve Body
FIGURE 5-41.
1. Bolt 3. Sleeve
2. End Cover 4. Valve Body
FIGURE 5-49.
1. Commutator 2. Valve Assembly
31. Set input shaft end facing up, then install seal 32. Using tool (1, Figure 5-53), install spacer (2)
ring (1, Figure 5-52) and seal (2). from small diameter end.
NOTE: Install the seal from the small diameter end. 33. Install snap ring (3, Figure 5-52).
Seal ring (1) and seal (2) are supplied stuck together 34. Fit seal (4) to input shaft, and install to upper
as one unit. Coat the new seal with oil, and install it cover.
from the lip end; - When doing this, coat thinly with
grease.
Installation
1. Lift emergency steering motor pump assembly
and bracket into position.
2. Install hose (3, Figure 6-2).
3. Install tube (2).
4. Connect motor wiring (1, Figure 6-1).
5. Refill oil to the specified level and run the
engine to circulate the oil through the system.
Then check the oil level again.
3. Remove head hose (3, Figure 6-3). FIGURE 6-3. STEERING CYLINDER PIPING
4. Remove rod hose (4).
1. Grease Tube 3. Head Hose
5. Disconnect grease tube (2, Figure 6-4). 2. Head Pin 4. Rod Hose
6. Remove rod pin (3).
7. Remove steering cylinder assembly (1).
Installation
1. Lift steering cylinder (1, Figure 6-4) into posi-
tion. Position rubber boot (1, Figure 6-5) and
install head pin (2, Figure 6-3). Install pin retain-
ing capscrew with washer and tighten to stan-
dard torque.
2. Position piston rod eye in bracket bore. Install
rubber boot (1, Figure 6-5) and pin. Install pin
retaining capscrew with washer and tighten to FIGURE 6-4. STEERING CYLINDER
standard torque. INSTALLATION
3. Connect grease tubes (2, Figure 6-4 & 1, Figure 1. Steering Cylinder 3. Rod Pin
6-3). 2. Grease Tube
4. Install rod hose (4, Figure 6-3).
5. Install head hose (3).
NOTE: When the piston rod assembly is pulled out c. Remove piston assembly (1, Figure 6-8) and
from the cylinder, oil will come out, so catch it in a cylinder head assembly (2) from rod (3).
container.
2. Piston assembly
1. Cylinder head assembly. a. Using ring expander (1, Figure 6-13), expand
a. Using push tool, press fit bushing (5, Figure piston ring (2).
6-11) in cylinder head (1).
Disassembly
1. Remove cover (2, Figure 6-20) from valve body Assembly
(1), then remove spring (3).
1. Fit backup ring and O-ring and install relief
valve assembly (12).
2. Fit backup ring and O-ring and assemble orifice
(11), then secure with plate (10).
3. Assemble demand spool (9), then fit O-ring and
The spring (3) is under an installed load of 35 kg. tighten plug (8).
(77 lbs.). Remove slowly using several long bolts. 4. Assemble poppet (7) and spring (6), then fit
2. Remove plate (4), screw bolts into threaded backup ring and O-ring and install plug (5), then
end of plug (5), and pull out plug, then remove secure with plate (4).
spring (6) and poppet (7). 5. Assemble spring (3), then fit O-ring and install
3. Remove plug (8), and pull demand spool (9) cover (2).
out.
4. Remove plate (10), screw bolts into threaded
end of orifice (11), and remove orifice.
5. Remove relief valve assembly (12).
RAISE
Movement of the hoist lever to the RAISE position The load check valve prevents oil from flowing out of
moves the spool valve to the end of the hoist valve. the raise side of the cylinders when the spool is
Refer to Figure 7-1. moved into and out of the RAISE position, thus pre-
venting the body from dropping.
Oil from the hydraulic pump enters port “A”. Because
the spool has blocked any further flow, the oil pres-
sure builds up until it opens the spring-loaded load
check valve to port “D”. The spool in the RAISE posi-
tion opens port “D” so oil is directed to the hoist cylin-
ders, through the RAISE line to extend the cylinders.
The return oil from the hoist cylinders goes into port
“C” past the spool to port “B” and to the hydraulic
tank.
HOLD
Located just below the raise position is the hold posi- The oil in the hoist cylinders is blocked at port “C”
tion. Moving the hoist lever down from the raise posi- and port “D” by the spool which prevents cylinder
tion, along with the centering spring, returns the movement.
spool to the HOLD position. Refer to Figure 7-2.
Oil from the hoist pump enters port “A” and goes
around the spool to port “B” and returns to the tank.
POWER DOWN
Movement of the hoist lever to the DOWN position Oil at port “D” returns from the hoist cylinders and is
moves the spool to the non-detent end of the hoist open to port “B” back to the tank.
valve. This moves the spool to the POWER DOWN
position. Refer to Figure 7-3.
Oil from the hoist pump enters PORT “A” and is
directed to port “C” by the spool. The oil going out
port “C” goes to the hoist cylinders to retract them.
FLOAT Hoist cylinder port “C” is open to port “A” to allow oil
to flow to the lower areas between the cylinder
Moving the hoist lever to the FLOAT position, the stages.
centering spring returns the spool to the FLOAT posi-
tion where the detent stops it. Refer to Figure 7-4. The truck should always be operated on the haul
road with hoist control valve in the FLOAT position.
Oil from the hoist pump enters port “A” and is
directed to port “B” by the spool and returns to the
tank. The oil in the hoist cylinders is also returned
back to the tank from port “D” to port “B”, due to the
spool location.
Removal
1. Drain hydraulic oil.
2. Disconnect control cable (1, Figure 8-1)).
3. Remove bracket (2).
4. Disconnect positioner cable (3).
FIGURE 8-1. HOIST VALVE INSTALLATION
5. Remove spring (4).
6. Remove bracket (5). 1. Control Cable 6. Hose
7. Remove hose (6). 2. Bracket 7. Tube
3. Positioner Cable 8. Tube
8. Remove tubes (7) and (8). 4. Spring 9. Hoist Valve
9. Remove hose (1, Figure 8-2). 5. Bracket
10. Remove hoist valve assembly (9, Figure 8-1).
Installation
1. Install hoist valve assembly.
2. Remove caps and plugs from hoses. Install
hose (1, Figure 8-2).
3. Install tubes (7 & 8, Figure 8-1).
4. Install hose (6).
5. Install bracket (5).
6. Install spring (4).
7. Install positioner cable (3).
8. Install bracket (2).
9. Install control cable (1).
10. Refill hydraulic tank oil to the specified level and
run the engine to circulate the oil through the
system. Then check the oil level again.
1. Hose 2. Bracket
Removal
The hoist control lever and hoist control valve are This control system is equipped with a hoist limit
connected by a mechanical control system consist- system, so when the body is rising, the hoist limit is
ing of a push-pull cable. actuated when the body reaches the position set for
the limiter.
Hydraulic Tank
Hoist Circuit
1. Remove plug (1, Figure 10-12) and install a 400 1. Power Up Port 2. Return Line
kg.cm2 (or a 5000 psi) pressure gauge.
2. Measure in the same way as when measuring
the hydraulic pressure in the hoist circuit.
Cause Remedy
Air in hydraulic oil A, C
Oil leakage in steering cylinder X
Installation
Screw breather valve (2, Figure 5-2) into tank (1).
Disassembly
1. Remove spring clamp (4, Figure 5-1) from out-
let.
2. Pull off rubber cover and screen (3).
3. Unscrew nut (5) from top of breather valve.
Remove cover (6), spring (7), and steel ball (8).
4. Slide valve assembly (9) from housing.
5. Disengage tapered spring (1) containing three
balls (2) from valve stem.
Assembly
1. Clean and inspect all parts. If valve, body, or
springs are damaged, replace complete
breather valve.
2. Install in order; tapered spring, one steel ball,
one cork ball and one hollow aluminum ball.
3. Engage three coils of spring on small end of
valve stem with hollow aluminum ball.
4. Install valve into housing.
5. Place steel ball (8) on top of valve. Install spring
(7).
6. Place cover (6) over spring. Screw on large nut
(5).
7. Install screen and rubber cover (3) over outlet.
8. Install spring clamp (4).
FIGURE 5-1. BREATHER VALVE
1. Tapered Spring 6. Cover
FUEL RECEIVER 2. Float Balls 7. Spring
3. Cover and Screen 8. Steel Ball
The fuel receiver (4, Figure 5-2) is normally mounted
4. Spring Clamp 9. Valve Assembly
on the fuel tank (1). Optional locations are the left
5. Nut
hand frame rail or at the Service Center.
Keep the cap on the receiver to prevent dirt build up
in valve area and nozzle grooves. If fuel spills from
tank breather valve or tank does not completely fill,
check breather valve to see that float balls are in
place and outlet screen is clean. If valve is operating
properly, the problem will be with the fuel supply sys-
tem.
MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M6-7
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M6-8
Basic Preliminary Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M6-8
DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M6-16
Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M6-16
Cleaning And Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M6-23
OPERATION MODES
(Refer to Figure 6-5): With no control pressure in the
pressure cavity, the fan clutch is always disengaged.
The thermal sensor (2) senses engine coolant tem-
FIGURE 6-3. OUPUT COMPONENTS perature through its thermal tip. The sensor is cali-
1. Facing Plates 3. Fan Mounting Hub brated to respond within a specific coolant
2. Clutch Hub temperature range by sending an electrical signal to
drive the solenoid (1). The operating range of the
thermal sensor can be determined by the tag
attached to the body. Engine lubrication oil enters the
solenoid through the inlet (NO) port. The pressure
Stationary Components
out (COM) opening of the solenoid valve is con-
(Refer to Figure 6-4): The shaft & bracket assembly nected by a line to the “control pressure” port of the
(1) is bolted to the engine and supports the fan clutch fan clutch bracket. The solenoid valve controls the
components. Pitot tubes (2) secured to the shaft speed of the vehicle cooling fan by regulating the
pump oil from the clutch, directing it back to the oil amount of oil pressure supplied to engage, modulate,
reservoir (engine oil pan). and allow release of the fan clutch. Oil exiting the
solenoid valve (and fan clutch) is directed to sump
through the “oil out” (NC) port in the solenoid valve.
Fully Engaged
When engine coolant temperature at the thermal tip
reaches the top of the designed temperature range of
the thermal sensor, full oil pressure is directed by the
solenoid valve into the pressure cavity of the fan
clutch. The control pressure forces the piston against
the clutch plates, clamping the disc stack against the
front bearing retainer. When the clutch plates are
fully clamped, the input and output are fully con-
nected constituting a 1:1 drive through the clutch.
The fan is thus driven at pulley speed.
Fully Released
When engine coolant temperature is at or below the
lower limit of the designed temperature range of the
thermal sensor, no oil pressure is directed into the
pressure cavity. Existing pressure in the cavity vents
to sump through the solenoid valve. NO clamping
force is applied to the clutch plates, and the drive to
the fan is disconnected. At this time, the fan merely
idles (at less than 300 rpm) due to viscous oil drag of
the cooling oil passing between the facing plates and
external clutch plates.
To test the clutch lock-up function, the clutch must be If an external source of oil supply is available, lock-up
supplied with a minimum of 275 KPa (40 psi) oil pres- can be tested with the engine shut down. Also, the
sure applied to the Control Pressure port. The oil minimum clutch plate torque capacity specification
supply can be from an external source capable of can be checked. Refer to 8c, Clutch Plate Wear, in
supplying engine oil at a minimum of 275 KPa (40 Maintenance for this procedure.
psi) and limited to a maximum of 689 KPa (100 psi)
or can be supplied by the engine running with a cool-
ant temperature within or above the thermal sensor
operating range. Refer to the operating temperature
rating tag on the thermal sensor to determine the
actual operating range.
NOTE 1: Actual 0.0 kPa (psi) will not be attained if tested under normal operating conditions (connected to a fan
clutch). 0.0 - 55 kPa (0.0 - 8.0 psi) internal clutch pressure will read on the gauge.
NOTE 2: As water temperature increases or decreases within the temperature range of the thermal sensor,
voltage output from the thermal sensor and pressure output from solenoid valve should also increase or decrease
(although not in direct proportion). An increase in water temperature produces an increase in voltage output and a
decrease in pressure.
14. Setup fan mounting hub assembly (2, Figure 6- 16. Remove tool from bore of hub and remove
20) on supports on bed of press. Insert tool #1D assembly from press.
through bore and press end cap (3) out.
15. Remove tool #1D and insert tool #1A. (1, Figure
6-21). If necessary, add support blocks to allow
clearance for sleeve bearings to drop out. Press
both sleeve bearings (4 & 5) out at the same
time.
h. Place supports under pulley adapter (1, Fig- FIGURE 6-29. REAR MAIN BEARING REMOVAL
ure 6-28). Remove snap ring (2). 1. Tool #5 3. Pulley Adapter
i. Use a punch to drive rear oil seal (3) out of 2. Tool #2 4. Bearing
bore.
NOTES:
• Some Shaft & Bracket Assemblies are constructed for manufacturing purposes as 2-piece units. DO
NOT separate the shaft from the bracket.
• Pipe plugs should be removed for cleaning, but must be reinstalled using Loctite® Primer N and
Loctite® #242.
• Be certain shaft oil ports are free and clear.
• The orifice plug may be removed for cleaning. Be certain it is reinstalled in the “Oil In” port.
FIGURE 6-38. BEARING RETAINER INSPECTION FIGURE 6-41. PISTON HOUSING INSPECTION
*Note: Any wear marks present in slots must not *Note: Dowel pin holes are 8.92 mm (0.351 in.) dia.
have straight sides that would restrict plate max. when new and may be elongated by wear.
movement. If wear marks have smooth entry and Maximum diameter across the elongated area
exit marks, the notches will not restrict plate must not exceed 9.53 mm (0.375 in.).Remove all
movement and the retainer may be reused. sealant.
7. Setup the bearing retainer (1, Figure 6-48) on 8. Remove front bearing retainer from press bed
supports as shown. and invert as shown in Figure 6-49. Place sup-
ports under bearing bore area.
a. Apply Loctite® Primer N to bearing (2) outer
race and bore of bearing retainer. a. Apply Loctite® Primer N to O.D. of oil seal
(2) and bore in bearing retainer.
b. Apply Loctite® #609 to above parts.
b. Apply Loctite® #242 to above parts.
c. Using tool #5, press bearing to bottom of the
bore in the retainer.
d. Install snap ring (4).
13. Install small sealring (4, Figure 6-53) as follows: 15. Position the clutch body/piston housing assem-
bly as shown in Figure 6-54.
a. Stretch sealring (4) by hand prior to installa-
tion so it will completely fill the groove and a. Apply Loctite® Primer N to piston housing in
remain there for further installation. balance plate seating area as shown.
b. Install sealring in groove, making sure it is b. Apply Loctite® #242 in same area.
not twisted.
c. Install balance plate (2) and the internal snap
14. Lubricate surfaces shown in Figure 6-53 and ring (1).
assemble:
a. Use a very light force to move the large seal-
ring (2) past the chamfer, and the body past
the small sealring (4).
b. Adjust the small sealring so the body passes
through it without damage.
c. Be certain dowels properly enter the dowel
holes (not the cast grooves) in the piston
housing (3).
Operational Test
Test for proper engagement, disengagement, and oil
leaks using OIL at both the “Oil IN” and “Control
Pressure” locations. DO NOT use air pressure.
1. The fan clutch should be fully locked up with
2.81 kg/cm2 (40 psi) oil pressure supplied to the
“control pressure” port.
2. Run the fan clutch with 82°C (180°F) oil sup-
plied to the “oil in” port for 2 hours. Manually
engage and disengage the clutch during test to
operate seals in both modes. Restrict fan
mounting hub rotation while clutch is disen-
gaged, but be sure fan mounting hub is
allowed to rotate freely while clutch is
engaged.
FIGURE 6-65. FINAL ASSEMBLY
1. Capscrews 4. O-Ring
2. Washers 5. Rear Section
3. Front Section
Fan clutch rotation causes the pitot tubes to
pump (lubrication) oil from inside the fan clutch,
maintaining low internal oil pressure. If lubricat-
29. Install fan belt pulley onto pulley adapter. Install
ing oil is supplied to the fan clutch before it is
capscrews and tighten to 5.0 - 5.9 kg.m (36 - 43
rotating in the proper direction, internal pres-
ft. lbs.) torque. Install fan spacer and/or engine
sures will become excessive, causing the oil
mounting bracket if applicable.
seals to leak.
Note: “Heavy side” indicators may be stamped in the
pulley and pulley adapter. These marks must be
located 180° apart to obtain the best balance.
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M7-5
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M7-6
Troubleshooting
SECTION C
PART
DESCRIPTION USE
NUMBER
Transmission
790-501-2000 Repair Stand
and Engine
SECTION C
PART
DESCRIPTION USE
NUMBER
799-203-8000 Tachometer Engine Speed
6215-81-3500 Adapter Engine Speed
SECTION D
PART
DESCRIPTION USE
NUMBER
Electrical
799-601-7400 T-Adapter Kit
Troubleshooting
Electrical
799-601-7200 Harness
Troubleshooting
Electrical
799-601-7300 Harness
Troubleshooting
SECTION F
PART
DESCRIPTION USE SERIAL RANGE
NUMBER
799-605-1001 Shift Checker Transmission BFP41-A & UP
799-607-1101 Modulation Checker Transmission BFP41-A & UP
799-607-2000 Shift Checker Transmission BFP41-A & UP, BFP42-A & UP
799-607-2120 Modulation Checker Use with 799-607-2000 only BFP42-A & UP, (Unit A10190 & UP)
799-607-3000 Shift Checker Transmission BFP42-A & UP, (Unit A10190 & UP)
NOTE: If shift checker 799-607-2000 is to be used on trucks serial number A10190 or higher, harness connector
799-607-2120 must be used. Or, use shift checker 799-607-3000 and connect directly to trucks with serial num-
bers A10190 & higher.
SECTION G
PART
DESCRIPTION USE
NUMBER
Differential
792-525-3000 Micrometer
Preload
SECTION G
PART
DESCRIPTION USE
NUMBER
Differential
790-425-1660 Wrench
Preload
SECTION G
PART
DESCRIPTION USE
NUMBER
792-530-1600 Large Seals
Push Tools
792-530-1700 Small Seals
1. Plate 5. Plate
2. Arm 6. Capscrew
3. Stud 7. Wing Nut
4. Plate 8. Washer
SECTION G
PART
DESCRIPTION USE
NUMBER
Ring Nut On
09003-07280 Spanner Wrench
Pinion Bearing
SECTION H
PART
DESCRIPTION USE
NUMBER
792-610-1000 Contains 2 Kits below
792-610-1100 Nitrogen Kit Adding Nitrogen
792-610-1200 Oil Charging kit Adding Oil
SECTION H
PART
DESCRIPTION USE
NUMBER
Front Suspen-
sion Flange
561-99-79220 Plate
Bushing Installa-
tion
NOTE: This item should be fabricated locally using
dimensions shown.
SECTION L
PART
DESCRIPTION USE
NUMBER
790-452-1100 Seal Installer Set
790-452-1110 Seal Protector Steering Valve
790-452-1120 Seal Installer Oil Seal
1. Seal Protector 3. Seal Compression
Installation
Compression 2. Seal Installer Ring
790-452-1130
Ring
SECTION L
PART DESCRIPTION
USE
NUMBER FEMALE THREAD MALE THREAD
WB-0987 0.75" - 14 BSPT (PT) 0.75" -14NPT
WB-1092 0.25" -18 NPT 0.25" -19BSPT (PT)
Adapter
WB-1093 0.50" -14 NPT 0.50" -14BSPT (PT)
WB-1094 0.75" -14 NPT 0.75" -BSPT (PT)
In order to adapt pressure test gauges using the "NPT" type threads com-
monly found in North America to the "PT" type threads used in the transmis-
sion and other areas of the truck, adapters are required.
1. Ring 4. Knob
2. Shaft 5. Spring Pin
3. Collar 6. Spring Pin
SECTION L
PART
DESCRIPTION USE
NUMBER
790-502-1003
Hydraulic
or Rebuild Stand
Cylinders
790-502-2000
790-102-3802
Wrench
or Gland Nut
Assembly
790-102-3791
SECTION L
PART
DESCRIPTION USE
NUMBER
790-302-1340 40 mm Socket Rod Nut
1. Expander 3. Clamp
2. Ring (rubber band)
SECTION L
PART
DESCRIPTION USE
NUMBER
799-101-5001 Hydraulic Tester Check Pressures
Digital Hydraulic
790-261-1102 Check Pressures
Tester
Other Data
This display indicates the status of If the truck engine is started before the preceding
the Inclinometer for the PLM II™, where "Power-up Process" is completed, the display will
shift to normal operation.
"CL : - -" indicates Inclinometer Not Used, and
"CL : oo" indicates Inclinometer Is Used. If the engine is running when the payload meter
starts up, only "o:XXX" and "d:XXX" will display
5. The display will show: before switching to normal operations.
NOTES:
1. The Option Code is set to "0" for trucks not
equipped with Modular Mining System (MMS)
(Except 530M/HD1500).
2. The 530M/HD1500 with Powertrain Manage-
ment Control (PMC) system uses "10" as the
setting for the Option Code.
3. For trucks with Modular Mining System (MMS)
or Scoreboard, the Option Code is "12".
This function will erase all of the cycle data, engine If there are no faults or warnings,
ON/OFF data, and fault/warning data. Total payload the display will show for 6 sec-
and the overall number of cycles will not be cleared. onds.
If there are current faults or warnings, the
IMPORTANT - Before clearing the data, download codes will be displayed in order of their priority,
the data to a personal computer. the highest priority first. Each code will flash for
To begin, the shift lever should be in the "N" position, 6 seconds.
the brake lock set, the hoist control lever should be in 5. After the current codes have been displayed,
the "FLOAT" position and the body in the down posi- past history codes that have been reset will be
tion. displayed. Each code will flash for 3 seconds.
1. Press and hold the MODE If there are no history codes or
switch until "Cd:dP" is displayed. after all history codes have been
2. Press the MODE switch once. shown, the display will show for 3
The display will show: seconds:
3. Press and hold the CAL/CLR The system will then proceed to the following
switch until "A.CLE" is flashing. displays: Refer to Page 25 for details.
4. Press the CAL/CLR switch again
and the memory will be cleared. The meter will
then return to normal operation. • Condition of the shift selector on mechanical
trucks or brake lock on electric trucks.
This does not clear the Operator Load Counter.
The panel will display: "C1:XX" for 3 seconds,
then indicate:
Mechanical trucks
"C1:oo" Shift selector is in "N".
"C1:- -" Shift selector is not in "N'.
Electric trucks
"C1:oo" Brake lock is on.
"C1:- -" Brake lock is off.
• Condition of the Body Up Switch signal.
The panel will display: "C2:XX" for 3 seconds,
then indicate:
"C2:oo" Body up switch is in up position.
"C2:- -" Body up switch is in down position.
INCLINOMETER
As the truck is tilted fore or aft, the weight distribution FIGURE 20-14. INCLINOMETER SIDE
between the front and rear axles changes. To com- CONNECTOR VIEW
pensate for this, the inclinometer measures the
ground angle at which the truck rests. This data is
Pin Number Wire Color Wire Function
then sent to the payload meter so it can calculate the
correct payload weight. The inclinometer is located 1 Black Ground (GND)
below the operator's center console (passenger seat 2 Red + Power
structure).
3 White Signal
Removal
Adjustment
1. Disconnect inclinometer wire lead from har-
ness. 1. Park the truck on a 0% grade.
2. Remove the three capscrews, nuts and lock- 2. Loosen the three inclinometer mounting cap-
washers (4, Figure 20-13) and inclinometer (3). screws (4, Figure 20-13) and rotate the incli-
nometer until a voltage range of 2.6 ± 0.1 volts
can be measured (using a volt-meter) at pins 1
and 2 of the inclinometer harness connector.
3. Tighten all capscrews (4, Figure 20-13) to stan-
dard torque, after the adjustment.
CN1 - AMP MIC-MKII 13 Pins White Connector CN3 - AMP MIC-MKII 9 Pins
No. Description Comments White (RS-232C Port)
3 Lamp Relay 2 2 SG
4 Lamp Relay 3 3 RD
5 Lamp Relay 4 4 TX
CN2 - AMP 040 12 Pins Black Connector CN4 - AMP 040 8 Pins Black
No. Description Comments (Optional Input, Reserved)
COMMON PROBLEMS
Suspension Charging
The Payload Meter II™ is a reliable controller and is rarely the source of failure in calculating payloads. The single
most common cause for an inaccurate payload estimate is improper suspension charging. Often maintenance per-
sonnel will not take the time to properly drain a suspension and carefully recharge it with oil and nitrogen. Most
often technicians will simply 'gas up' the suspensions with more nitrogen and send a truck back into service.
Komatsu engineers have conducted tests at customer sites to monitor suspension charging on trucks and found
many trucks to be improperly charged. Trucks with poorly charged suspensions were sent to service bays for main-
tenance by mine personnel. In some cases these trucks were returned to operation in worse condition than when
they were first checked because service personnel did not take the time to carefully charge the suspensions.
The payload meter uses the pressures from the suspensions to calculate payload. As the truck is loaded, a flat sus-
pension will completely collapse. The top suspension cap will make metal-to-metal contact with the bottom. This
often occurs in the rear suspensions. The pressure in the suspension will not accurately reflect the force applied to
the suspension by the weight of the material in the body and inaccurate payload calculations will result.
In addition to inaccurate payload calculations, improperly charged suspensions increase wear-and-tear on truck
frames and tires, increasing maintenance costs over the life of the truck. Each over-loaded haul cycle with under-
charged suspensions leads to premature failure. Consistently low payload estimates are the first sign that the sus-
pensions are not being properly maintained and the truck is on a path toward increased operating costs and
system failures. Thankfully, the effects of improper suspension charging can be postponed with proper service and
care.
Specific suspension charging procedures for each truck model can be found in the shop manual. In general, the fol-
lowing items are very important for proper charging:
• Completely discharge the suspension. This may take more than an hour for the nitrogen and oil to completely
discharge. However, to ensure that the proper volume of fresh oil is added, it's necessary to remove as much
of the oil/nitrogen mixture as possible.
• Fill the suspension to the proper height with fresh oil, this is critical to keeping the suspensions from bottoming
out.
• Charge the suspension to the proper height with nitrogen.
Refer to Section “H” for the proper charging procedures.
This module contains an example of how to use the Scope program from Komatsu to monitor suspension pressure
data.
⎛ 410 ⎞
Voutput = 1 + 4 × ⎜ ⎟ = 1.576vdc
⎝ 2845 ⎠
Don’t forget to add the 1v since the output of the pressure sensor at 0 psi is 1 volt
The generic version is:
⎛ Suspension _ pressure ⎞
Voutput = 1 + 4 × ⎜ ⎟
⎝ 2845 ⎠
volts
Voutput = 2.6 volts - 0.103 degree x 5° = 2.085volts
Connector 7821915320
Terminal 7821915010
Connector 7830115260 Connector 7845253670
Terminal 7821912020 Terminal 7827101440
Plate 7821912510 Plate 7821912450
A:A:
PLM RTS
PLM RTS
B:B:
PLM SGND
PLM SGND
C:C:
PLM Rxd
PLM Rxd
D:D:
PLM Txd
PLM Txd
E:E:
PLM CTS
PLM CTS
MATING FACE OF
BRAKE LOCK DOWNLOAD
CONNECTOR CONNECTOR
Originally, this program was designed for engineering testing purposes only. It was not designed for general distri-
bution or use. This program sets the Komatsu Mining Systems Payload Meter II™ into real-time data transfer
mode. This allows the technician to monitor all inputs into the system. Scope also allows for the logging of this
real-time data. These files can be used to analyze the inputs over a period of time.
Scope is used to record suspension pressures during a haul cycle. These pressures can be imported into Microsoft
Excel or other spreadsheet programs to graph each suspension. Visually, a service technician can look for flat or
undercharged suspensions. In addition, all the input to the payload meter can be checked using the PC instead of
the switches on the front panel of the payload meter
System Requirements - Microsoft Windows 95, access to serial communications port 1, EF9159 & EF9160 har-
nesses to connect the Payload Meter II™ to the serial port of the PC. Payload Meter II™ must also be set up to use
MMS Communications Mode. This is indicated on power up of the Payload Meter by OP12. Changing this setting is
described in “Setting the Option Code”.
Downloading Scope – Scope is available on the internet. It can be found at the following address:
http://www.kms-peoria.com/payload
The program, Scopezipped.exe, is a self-extracting executable. Save it into its own directory on your hard drive
and run it. The program will unzip and be ready to run.
NOTE: This program has not been tested on all versions of Windows and may not work on all operating systems.
Using Scope
1. Start Scope Payload Meter II™.
2. Power the Payload Meter II™ System.
3. StartRTM - Start real time communications soon after the payload meter finishes it’s initial display of internal
settings. This display cycle is described in “Displays at Start-Up”.
4. The Scope window should now indicate real-time conditions. The RTM D I/O conditions show the inputs into
the Payload Meter II™. The suspension pressures, inclinometer, speed, and truck status displayed are the
current readings from all sensors. This display will remain live as long as the communications connection is
maintained.
5. To create a record of the data being transmitted by the Payload Meter II™, press StartLog. The program will
prompt for a file name. Once entered, Scope will begin to save data to this file.
6. Use the StopLog command to stop logging data to the file.
7. Use the StopRTM command to stop real time communications. After a period of time, the payload meter
should indicate a communications error.
In the sample data shown, the column marked "Type" refers to the type of data being transmitted; “R” is used for
Real-Time, “F” is used for Final Load and “S” is used for Swing Load.
For the swing load data line the format is Time, S, Swing Load, Predicted Load, FL, FR, RL, RR.
For a final load transmission the format is Time, F, Final Load, FL, FR, RL, RR.
The Payload Meter requires 5 wire RS232 communications. Payload Meter communications connections are :
1 - RTS 2 - Signal Ground 3 - RxD 4 - TxD 5 - CTS
As shown in the previous examples, Scope can be used to create log files of the suspension pressure data.
Graphs of this data can give be used to determine the relative health of the suspensions.
FUNCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M28-3
MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M28-7
1000 Hour Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M28-7
Gate Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M28-7
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M28-8
Operational Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M28-8
System Component Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M28-9
Exhaust brake ON
Refer to Figure 28-2:
When the transmission controller actuates the sole-
noid valve, the following occurs:
The solenoid valve opens the port to the exhaust
brake cylinder. Then air flows from the air tank to the
exhaust brake cylinder and causes it to close the
exhaust pipe, and the exhaust brake operates.
FIGURE 28-2. EXHAUST BRAKE ON
Gate Adjustment
The engine should be able to fully combust fuel at
idle and should not labor excessively when brake is
applied. If problems are encountered, check gate
adjustment setting.
1. Measure dimension “A” as shown in Figure 28-
8. Dimension should be 32 ± 1 mm (1.25 ± 0.04
in.)
2. If necessary, loosen gate adjust screw locknut
and adjust screw to obtain correct dimension.
3. After adjustment, tighten locknut to 2.5 kg.m
(18 ft. lbs.) torque.
Intermittent Operation
Brake Won't Release
CAUSE
Possible Symptoms of Malfunctioning Exhaust
Broken Air Line X
Brake:
Insufficient Air Supply X X
Unusual noises or clanking sound as exhaust
Loose Electrical Connection X X X brake is applied or released.
Blown Fuse X An abnormal vibration is felt when exhaust
Solenoid Valve Failure X brake is applied or released.
Controller Circuit Failure X Engine seems to be straining or feels
Lock-up Circuit Failure X underpowered. If this occurs, check and
correct system immediately.
Plugged Cylinder Breather X X
Excessive exhaust smoke when brake is
Damaged Brake Cylinder X X X X X released.
Damaged Cylinder Seal X X Engine temperature exceeds normal levels.
Defective ON/OFF Switch X X
Leaky Gasket X If the above symptoms occur, the truck should be
Loose Mounting Bolts X removed from service until the exhaust brake
system is inspected and the problem corrected.
Plugged Quick Release X X X X
Valve
Carbon in Brake Body X X X
Incorrect Gate Adjustment X X
Worn Return Springs X X
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M29-6
AS-2: Fault Code 1.0 Engine speed sensor, open circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M29-13
AS-3: Fault Code 1.1 Right rear wheel speed sensor, open circuit . . . . . . . . . . . . . . . . . . . . . . . M29-14
AS-4: Fault Code 1.2 Left rear wheel speed sensor, open circuit . . . . . . . . . . . . . . . . . . . . . . . . M29-15
AS-5: Fault Code 1.3 Transmission output speed sensor, open circuit . . . . . . . . . . . . . . . . . . . . M29-16
AS-8: Fault Code 4.3 ASR/ARSC caution lamp system, open circuit. . . . . . . . . . . . . . . . . . . . . . M29-19
AS-9: Fault Code 4.5 Central warning lamp and buzzer system, open circuit . . . . . . . . . . . . . . . M29-20
AS-10: Fault Code 5.3 ASR/ARSC caution lamp system, short to ground . . . . . . . . . . . . . . . . . . M29-21
AS-11: Fault Code 5.5 Central warning lamp and buzzer system output, short to ground . . . . . . M29-22
AS-14: Fault Code 6.2 Left rear wheel speed sensor failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . M29-25
AS-15: Fault Code 8.0 Left pressure control valve failure - valve does not open . . . . . . . . . . . . . M29-26
AS-16: Fault Code 8.1 Short to ground in right pressure control valve circuit . . . . . . . . . . . . . . . M29-27
AS-17: Fault Code 8.2 Short to ground in left pressure control valve circuit . . . . . . . . . . . . . . . . M29-28
AS-18: Fault Code 8.3 Right pressure control valve system, open circuit . . . . . . . . . . . . . . . . . . M29-29
AS-19: Fault Code 8.4 Failure in right pressure control valve system - LH valve does not close . .M29-30
AS-20: Fault Code 8.5 Right pressure control valve system failure (valve does not close) . . . . . M29-31
AS-21: Fault Code 8.6 Left pressure control valve system failure (valve does not close). . . . . . . M29-32
AS-22: Fault Code 8.7 Right pressure control valve system failure (valve does not open) . . . . . M29-33
AS-23: Fault Code 8.9 Short to ground in ASR shut-off valve system . . . . . . . . . . . . . . . . . . . . . M29-34
AS-24: Fault Code 9.0 Open circuit in ASR shut-off valve system . . . . . . . . . . . . . . . . . . . . . . . . M29-35
AS-25: Fault Code 9.1 Failure in ASR shut-off valve system - valve does not close . . . . . . . . . . M29-36
AS-26: Fault Code 9.2 Failure in ASR shut-off valve system - valve does not open . . . . . . . . . . M29-37
Wheel Speed Sensors When the truck is turned, the steering angle position
is suppled to the controller and as long as the wheel
The wheel speed sensors (7 & 8) generate a pulsed speed difference is within normal limits, ASR remains
voltage signal as the teeth of the speed sensor gear off.
on each rear wheel pass across the face of the sen-
sor. The signal frequency is directly proportional to
the rotational speed of the wheel (and gear). The When actuated (when the truck starts to move):
controller then calculates wheel speed based on the
As shown in the graph in Figure 29-3, when the dif-
frequency of the signal.
ference in the rotating speed between the left and
right wheels is detected, the brake is applied to the
wheel that is slipping in order to reduce its speed
Steering Angle Sensor until both the left and the right wheel are rotating at
The steering angle sensor (10) is a potentiometer the same speed.
that changes resistance as the operator turns the t0 : Starting to depress accelerator pedal when
steering wheel. The sensor sends a variable voltage truck begins to move from a standstill.
signal to the controller based on the angle of the cen-
t1 : If the rear right wheel starts to slip and the
ter lever.
difference between the speed of the left and right
rear wheels is more than the set value, the
controller sends a stepped increase signal to
Pressure Switching Valve apply the brake gradually to the wheel that is
slipping.
The pressure switching valve (5) supplies air to the
left and right pressure control (ASR) valves. When t2 : When the acceleration of the wheel on the
the ASR system is turned On, the controller ener- side that is slipping goes below the set value, the
controller sends the maintain signal. When the
gizes this valve.
slippage starts to decrease, the controller
If a system failure occurs, the controller will de-ener- gradually sends the signal to exhaust, and
gize this valve to cut off air to the pressure control repeats the control so that the speed of the left
vales to turn the system off. and right wheels is the same.
1.0 X X Open circuit, short circuit to ground, short circuit in engine speed sensor system 1 AS-2
1.5 X Short circuit to ground in retarder oil temperature sensor system 1 See Note
1.8 X Open circuit, short circuit to ground in suspension pressure sensor (left) system 1 See Note
1.9 X Open circuit, short circuit to ground in suspension pressure sensor (right) system 1 See Note
4.2 X Open circuit, short circuit in exhaust brake signal system 2 See Note
4.3 X X Open circuit, short circuit in ASR/ARSC caution lamp system 1 AS-8
4.4 X Open circuit in ARSC Standby lamp system 2 See Note
4.5 X X Open circuit, short circuit in central warning lamp system or buzzer system 2 AS-9
5.2 X Short circuit to ground in exhaust brake signal system 2 See Note
5.3 X X Short circuit to ground in ASR/ARSC caution lamp system 1 AS-10
5.4 X Short circuit to ground in ARSC Standby lamp system 2 See Note
5.5 X X Short circuit to ground in central warning lamp system or buzzer system 2 AS-11
7.1 X Open, short circuit in speed display down output 2 See Note
7.2 X Open, short circuit in speed display clear output 2 See Note
7.3 X Short circuit to ground in speed display up output 2 See Note
7.4 X Short circuit to ground in speed display down output 2 See Note
7.5 X Short circuit to ground in speed display clear output 2 See Note
8.1 X X Short circuit to ground in pressure control valve system (right) 1 AS-16
8.2 X Short circuit to ground in pressure control valve system (left) 1 AS-17
8.3 X X Open, short circuit in pressure control valve system (right) 1 AS-18
8.4 X Open, short circuit in pressure control valve system (left) 1 AS-19
8.5 X X Failure in RH pressure control valve system (valve remains open) 1 AS-20
8.6 X Failure in LH pressure control valve system (valve remains closed) 1 AS-21
8.7 X X Failure in RH pressure control valve system (valve does not open) 1 AS-22
9.5 X Open, short circuit to ground in travel speed set switch system 1 See Note
NOTE: If the fault code is specific to the ARSC system as indicated by the “X” in the Applicable System column, refer to Automatic Retard
Speed Control (ARSC) System in this Section of the manual for troubleshooting procedures.
Note: In the electrical schematics on the following pages, the ASR/ARSC controller may be labelled either ASR
controller or ARSC controller. Both systems share the same controller unit.
1. Always connect any disconnected connectors before proceeding to the next step.Troubleshooting is per-
formed while the fault is being generated. When the connector is disconnected and the T-adapter is inserted,
or when the T-adapter is removed and the connector reinstalled, if the error code is no longer displayed, then
the system has been reset.
2. Before troubleshooting, be certain all connectors are properly inserted.
3. Always connect any disconnected connectors before proceeding to the next step.
4. Disconnect connectors CR1 and CR2; after approximately 3 seconds, the failure code(s) should clear.
R-2: Fault Code 1.0. . . .Engine speed sensor, open circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M30-8
R-3: Fault Code 1.3. . . . Transmission output speed sensor, open circuit . . . . . . . . . . . . . . . . . . . . M30-9
R-4: Fault Code 1.5. . . .Retarder oil temperature sensor system fault . . . . . . . . . . . . . . . . . . . . . . M30-10
R-6: Fault Code 1.8. . . .Left suspension pressure sensor system fault . . . . . . . . . . . . . . . . . . . . . M30-12
R-7: Fault Code 1.9. . . . Right suspension pressure sensor system fault . . . . . . . . . . . . . . . . . . . . M30-13
R-8: Fault Code 4.2. . . . Exhaust brake selector signal, open circuit . . . . . . . . . . . . . . . . . . . . . . . M30-14
R-9: Fault Code 4.3. . . .ASR/ARSC caution lamp system, open circuit . . . . . . . . . . . . . . . . . . . . . M30-15
R-10: Fault Code 4.4. . .ARSC operation (standby) lamp system, open circuit . . . . . . . . . . . . . . . . M30-16
R-11: Fault Code 4.5 . .Central warning lamp and buzzer system, open circuit . . . . . . . . . . . . . . . M30-17
R-12: Fault Code 5.2 . .Exhaust brake selector signal output system, short to ground . . . . . . . . . M30-18
R-13: Fault Code 5.3 . .ASR/ARSC caution lamp system, short to ground . . . . . . . . . . . . . . . . . . . M30-19
R-14: Fault Code 5.4 . .Short to ground in ARSC operation (standby) lamp output circuit . . . . . . M30-20
R-15: Fault Code 5.5 . .Central warning lamp and buzzer system output, short to ground . . . . . . M30-21
R-17: Fault Code 7.1. . . Travel speed display system UP output, open circuit . . . . . . . . . . . . . . . M30-23
R-18: Fault Code 7.1 . .Travel speed display system DOWN output, open circuit . . . . . . . . . . . . . M30-24
R-19: Fault Code 7.2. . . Travel speed display system CLEAR output, open circuit . . . . . . . . . . . . M30-25
R-20: Fault Code 7.3. . . Travel speed display system UP output, short to ground . . . . . . . . . . . . . M30-26
R-22: Fault Code 7.5 . . Travel speed display system CLEAR output, short to ground . . . . . . . . . . M30-28
R-23: Fault Code 8.1 . . Pressure control valve system, short to ground . . . . . . . . . . . . . . . . . . . . . M30-29
R-24: Fault Code 8.3 . . Pressure control valve system, open circuit . . . . . . . . . . . . . . . . . . . . . . . . M30-30
R-25: Fault Code 8.5 . . Pressure control valve failure (valve remains open) . . . . . . . . . . . . . . . . . M30-31
R-26: Fault Code 8.7 . . Pressure control valve failure (valve fails to open) . . . . . . . . . . . . . . . . . . . M30-32
R-27: Fault Code 8.9 . . Shut-off valve system, short to ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . M30-33
R-28: Fault Code 9.0 . . Shut-off valve system, open circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M30-34
R-29: Fault Code 9.1 . . Shut-off valve system failure (valve remains open) . . . . . . . . . . . . . . . . . M30-35
R-30: Fault Code 9.2 . . Shut-off valve system failure (valve fails to open) . . . . . . . . . . . . . . . . . . . M30-36
R-31: Fault Code 9.3 . . ARSC system switch, open circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M30-37
R-32: Fault Code 9.4 . . ARSC system switch, short to ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . M30-38
R-33: Fault Code 9.5 . . Travel speed setting switch, open circuit or short to ground . . . . . . . . . . . M30-39
R-103: Retarding effort excessive when empty or ineffective when truck is loaded . . . . . . . . . . . . . M30-44
R-105: No retarder control when traveling downhill even when set speed is exceeded . . . . . . . . . . M30-45
R-106: Central warning lamp (or buzzer) stays on (or off) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M30-46
R-107: STANDBY (READY) lamp does not light (or remains lit) . . . . . . . . . . . . . . . . . . . . . . . . . . . M30-47
R-109: Travel speed value and machine value model do not agree . . . . . . . . . . . . . . . . . . . . . . . . . M30-51
1.0 X X Open circuit, short circuit to ground, short circuit in engine speed sensor system 1 R-2
1.5 X Short circuit to ground in retarder oil temperature sensor system 1 R-4
1.8 X Open circuit, short circuit to ground in suspension pressure sensor (left) system 1 R-6
1.9 X Open circuit, short circuit to ground in suspension pressure sensor (right) system 1 R-7
4.2 X Open circuit, short circuit in exhaust brake signal system 2 R-8
4.3 X X Open circuit, short circuit in ASR/ARSC caution lamp system 1 R-9
4.4 X Open circuit in ARSC Standby lamp system 2 R-10
4.5 X X Open circuit, short circuit in central warning lamp system or buzzer system 2 R-11
5.5 X X Short circuit to ground in central warning lamp system or buzzer system 2 R-15
8.0 X Failure in LH pressure control valve (valve remains closed) 1 See Note
8.1 X X Short circuit to ground in pressure control valve system (right) 1 R-23
8.2 X Short circuit to ground in pressure control valve system (left) 1 See Note
8.3 X X Open, short circuit in pressure control valve system (right) 1 R-24
8.4 X Open, short circuit in pressure control valve system (left) 1 See Note
8.5 X X Failure in RH pressure control valve system (valve remains open) 1 R-25
8.6 X Failure in LH pressure control valve system (valve remains closed) 1 See Note
8.7 X X Failure in RH pressure control valve system (valve does not open) 1 R-26
9.5 X Open, short circuit to ground in travel speed set switch system 1 R-33
X Retarding effort excessive when empty or ineffective when truck is loaded R-103
X No retarder control when travelling downhill, even when set speed is exceeded R-105
X Travel speed value and machine model value do not agree R-109
NOTE: If the fault code is specific to the ASR system as indicated by the “X” in the Applicable System column, refer to ASR (Automatic Spin
Regulator) System in this Section of the manual for troubleshooting procedures.
Note: In the electrical schematics on the following pages, the ASR/ARSC controller may be labelled either ASR
controller or ARSC controller. Both systems share the same controller unit.
A. Fault in model selection; when key switch is turned ON, truck model shown on LED display is incorrect.
1. Tank
2. Bracket
3. Bolt
4. Washer
5. Bolt
6. Washer
7. Clip
Service
If windshield washer maintenance is required, check BODY DUMP CONTROL LINKAGE
the following;
Figure 3-3 shows the body dump control lever and
1. Obstructions in the inlet to the pump. associated linkage mounted in the cab.
2. Kinked supply hose to the nozzle. The linkage should be lubricated at 2000 hour inter-
3. Check for system voltage at the pump termi- vals as described in Section "P", Lubrication and Ser-
nals. If voltage is not OK, check the wire har- vice.
ness or the wiper switch. If the voltage is OK at
Refer to Section L for linkage adjustment procedure.
the pump, replace the entire pump assembly.
REFRIGERANT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . N4-21
Recycled Refrigerant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . N4-21
Reclaimed Refrigerant. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .N4- 21
Refrigerant Quantity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .N4- 21
R-134a Refrigerant Containers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . N4-21
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .N4-38
Pre-Diagnosis Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .N4-38
Preparing For Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .N4-38
Preliminary Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .N4-38
System Performance Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .N4-38
Diagnosis Of Gauge Readings And System Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .N4-39
Removal
1. Remove capscrews (3, Figure 4-2).
2. Lift seat assembly and disconnect air compres-
sor wiring harness.
3. Remove seat assembly (1) from cab.
Installation
1. Position spacers and seat in recessed area of
cab floor.
2. Connect air compressor wiring harness to truck
harness.
3. Install and tighten capscrews (3, Figure 4-2) to
standard torque.
4. Verify proper operation of air compressor and
other seat functions.
Reclaimed Refrigerant
Reclaimed refrigerant has been filtered through a
R-134a Refrigerant Containers
more thorough filtering process and has been pro-
cessed to the same standards of purity as virgin Two basic, readily available containers are used to
refrigerant. Because of this, reclaimed refrigerant is store R-134a: the 30 or 60 pound bulk canisters (Fig-
acceptable for use in all systems, not just mobile. ure 4-8).
The reclaiming equipment used for this process is
Always read the container label to verify the contents
expensive, and therefore, not common among nor-
are correct for the system being serviced. Note the
mal maintenance shops. Equipment such as this is
containers for R-134a are painted light blue.
more commonly found in air conditioning specialty
shops.
Refrigerant Quantity
If not enough refrigerant is charged into the system,
cooling ability will be diminished. If too much refriger- FIGURE 4-8. R-134a CONTAINERS
ant is charged into the system, the system will oper-
ate at higher pressures, and in some cases, may 1. 30 lb. Cylinder 2. 60 lb. Cylinder
damage system components. Exceeding the speci-
fied refrigerant charge will not provide better cooling.
If an incorrect charge is suspected, recover the
refrigerant from the system, and charge the system
with the correct operating weight (6.9 lb, 3.13 kg).
This is not only the recommended procedure, but it is
also the best way to ensure that the system is operat-
ing with the proper charge and providing optimum
cooling. Using the sight glass to determine the
charge is not an accurate method.
8 24 - 29 ft.lbs. 33 - 39 Nm
10 26 - 31 ft.lbs. 36 - 42 Nm
Only SAE and/or Mobile Air Conditioning Society
12 30 - 35 ft.lbs. 41 - 47 Nm
(MACS) approved flushing methods with the
appropriate refrigerants are to be performed Installation torque for the single M10 or 3/8 in. cap-
when removing debris from the system. Other screws securing the inlet and outlet fittings onto the
methods may be harmful to the environment, as compressor ports is 11 - 25 ft.lbs. (15 - 34 Nm).
well as air conditioning components.
Expansion Valve
When removing the expansion valve from the sys-
tem, remove the insulation, clean the area and dis-
connect the line from the receiver-drier. Detach the
capillary (bulb) and external equalizer tube (if
present) from their mounting locations. Remove the
expansion valve from the evaporator inlet. Expansion
valve service is limited to cleaning or replacing the fil-
ter screen. If this is not the problem, replace the
valve. Secure the capillary and equalizer, if used, to
clean surfaces and replace or attach any insulating
material.
Compressor
NOTE: Some compressors may be discarded
The compressor can fail due to shaft seal leaks (no because it is suspected that internal components
refrigerant in the system), defective valve plates, within the compressor have seized. Ensure that
bearings, or other internal parts or problems associ- the compressor clutch is working properly before
ated with high or low pressure, heat, or lack of lubri- discarding a compressor for internal seizure. The
cation. Be sure the compressor is securely mounted normal compressor life span should be about
and the clutch pulley is properly aligned with the twice as long as the normal life span of the com-
drive pulley. pressor clutch.
Use a mechanic's stethoscope to listen for noises It is important to note that often times a weak clutch
inside the compressor. coil may be mistaken for a seized compressor. When
a coil’s resistance has increased over time and the
magnetic field weakens, the coil may not be able to
pull the load of the compressor. Failure of the coil to
allow the compressor shaft to be turned, may appear
as though the compressor is locked up.
FIGURE 4-17.
FIGURE 4-20.
FIGURE 4-19.
FIGURE 4-21. If the resistance of the coil is not within the specifica-
tions, the clutch will not operate properly. Remove
1. Pulley Assembly 3. Retaining Ring Pliers the retaining ring and replace the coil.
2. Pulley Retainer Ring
FIGURE 4-23.
1. Bearing Installer 2. Universal Handle
Indications:
Low side pressure - VERY LOW
High side pressure - VERY LOW
Discharge air is warm.
No bubbles observed in sight glass, may show oil
streaks.
- Pressure sensing switch may have compressor Add refrigerant (make sure system has at least
clutch disengaged. 50% of its normal amount) and leak test system.
It may be necessary to use a jumper wire to
-
enable the compressor to operate, if the com-
- Refrigerant excessively low; leak in system. pressor has shut down due to faulty pressure
sensing switch. Repair any leaks and evacuate
the system if necessary, Replace the receiver-drier
if the system was opened. Recharge the system
using a scale and add oil as necessary. Check
AC operation and do system performance test.
Indications:
Low side pressure - LOW.
High side pressure - LOW.
Discharge air is warm.
The low pressure switch may have
shut off the compressor clutch.
Leaks Found:
Add refrigerant (make sure system has at least
50% of its normal amount) and leak test system.
It may be necessary to use a jumper wire to
enable the compressor to operate, if the com-
pressor has shut down due to faulty pressure
sensing switch. Repair any leaks and evacuate
the system if necessary, Replace the receiver-drier
if the system was opened. Recharge the system
using a scale and add oil as necessary. Check
AC operation and do system performance test.
Indications:
Low side pressure - Normal
High side pressure - Normal
Discharge air is only slightly cool.
(In a cycling type system with a
thermostatic switch, the switch may not cycle
the clutch on and off, so the low pressure
gauge will not fluctuate.)
Indications:
Low side pressure - HIGH
High side pressure - HIGH
Discharge air is only slightly cool.
Indications:
Low side pressure - VERY LOW or in a Vacuum
High side pressure - HIGH
Discharge air only slightly cool.
Expansion valve body is frosted or sweaty.
Indications:
Low side pressure - HIGH
High side pressure - Normal
Air from vents in the cab seems warm
or only slightly cool.
Indications:
Low side pressure - LOW
High side pressure - Normal to HIGH
Discharge air is only slightly cool.
Look for sweat or frost on high side hoses
and tubing. The line will be cool to the touch
near the restriction.
Indications:
Low side pressure - HIGH
High side pressure - LOW
Compressor operates noisily.
Indications:
Low side pressure - Normal
High side pressure - Normal
Low side pressure may cycle within a smaller
range as the compressor clutch cycles
more frequently than normal. This may indicate
the thermostat is set too high.
Indications:
Low Side High
High Side High
Discharge air may be warm.
High pressure hoses and lines are very hot.
POSITION:
D Range - F2 - F7 Depress the button again to turn
L Range - F1 - F2 Off the emergency steering.
D Range - F2 - F6 When the switch is ON, the RED
L Range - F1 lamp in the switch will light. The
red warning light on the right-
When the switch position is OUT the light is OFF. hand side of the instrument panel
When the switch position is IN the light is ON. will also light.
STOPPING IN EMERGENCY
1. ASR System Switch (ON/OFF) 5. Accelerator Pedal 9. ARSC Set Speed Display
2. ARSC System Switch (ON/OFF) 6. ASR/ARSC Caution Lamp (Red) 10. Retarder Control Lever
3. ARSC Set Lever 7. ARSC Standby Lamp (Green) 11. Central Warning Lamp
4. Brake Pedal 8. ASR Operation Lamp (Green) 12. Exhaust Brake Switch
Brake Pedal
When ASR is active, if the brake pedal (4) is
depressed, ASR operation is stopped.
• Used when setting the travel speed. The set speed display (9) displays the speed (km/h
or MPH) that has been set.
• Used when making fine adjustments up or down
to the set speed. (Tap Up/Tap Down) • When the key switch or the system switch is
turned ON, the display initially shows “– –”, and
• Used when canceling the set speed. then will display “0” until the speed is set.
• The display turns off when the system switch is
OFF.
Brake Pedal
• It displays “0” when the set value is canceled.
The brake pedal (4) can be used to apply the service
brakes even though the ARSC system is activated.
Retarder Control Lever
Accelerator Pedal Even if the ARSC system is active, the retarder can
be controlled with the retarder control lever (10).
The ARSC system is actuated only when the acceler-
ator pedal (5) is released.
Central Warning Lamp
This lamp (12) lights up together with the ASR/ARSC
caution lamp if there is a serious abnormality in the
ARSC system when the system switch is On.
Relationship With Exhaust Brake On slippery road surfaces, the wheels may lock
If the exhaust brake switch (12, Figure 5-3) is in the when the ARSC system is actuated. IF ROAD
ON position, the exhaust brake is actuated normally CONDITIONS ARE POOR, DO NOT USE THE
when the accelerator pedal is released if the torque ARSC SYSTEM.
converter lock-up is On. If the truck attempts to
exceed the set speed, the ARSC is actuated. If a problem occurs in the system and it becomes
impossible to maintain accurate control of the
If the exhaust brake switch is in the OFF position, the truck, a warning is given, the system will turn Off
exhaust brake is not actuated when the ARSC is if a serious problem has occurred and the ASRC
being operated. If the foot brake or retarder control system is released. The operator should then use
lever are operated, the exhaust brake is actuated the foot brake and retarder control lever to main-
normally. tain control and move the truck to a safe place,
If the downhill slope is not steep and the engine then turn the system switch OFF.
brake and exhaust brake have ample effect, the truck
will not accelerate to the set travel speed and the
ARSC may not be actuated.
1.0 X X Open circuit, short circuit to ground, short circuit in engine speed sensor system 1
1.7 X X Open circuit, short circuit to ground, short circuit in accelerator signal system 1
1.8 X Open circuit, short circuit to ground in suspension pressure sensor (left) system 1
1.9 X Open circuit, short circuit to ground in suspension pressure sensor (right) system 1
4.5 X X Open circuit, short circuit in central warning lamp system or buzzer system 2
5.5 X X Short circuit to ground in central warning lamp system or buzzer system 2
8.0 X Failure in pressure control valve (left) or failure in pressure switch 2 system 1
Failure in pressure control valve system (retarder remains applied) or failure in pres-
8.5 X X 1
sure switch 1 system
Failure in pressure control valve system (retarder has no affect) or failure in pressure
8.6 X 1
switch 1 system
8.7 X X Failure in pressure control valve system (right) or failure in pressure switch 1 system 1
Failure in pressure cracking valve (does not open) or failure in pressure switch 2 sys-
9.2 X X 1
tem
9.3 X Open circuit, short circuit in system switch (See Note below) 1
NOTE: If the failure code is “9.3” or “9.4”, it indicates a failure in the system switch. Even though the ARSC system switch is turned OFF, the
central warning lamp and ASR/ARSC caution lamp will flash and the buzzer will sound.
Shift Indicator
Fuel Gauge
The shift indicator (17) indicates the lever
position of the transmission range selector. The fuel gauge (22) indicates the
amount of fuel in the fuel tank. If there
is more than 170 liters (45 gal) of fuel in
the tank while the engine is operating,
the green range lights. If there is less
than 170 liters (45 gal) of fuel in the
tank, the red range lights.
When the top light (P) is lit, the power mode selector
switch on the console (3, Figure 5-2) is in POWER
MODE.
When the bottom light (E) is lit, the Power mode
selector switch is in the ECONOMY MODE.
Engine Oil Pressure Monitor This switch (35) is used to change the braking
The engine oil pressure monitor method according to the road conditions.
(31) indicates low engine oil This position (switch OUT - light OFF)
pressure. is used when traveling on normal road
If the lamp flashes and alarm surfaces. Braking force is applied to
buzzer sounds, stop the engine both front and rear wheels.
and carry out inspection. Action This position (switch IN - light ON) is
code “04” will be indicated. used when traveling on slippery roads.
Braking force is applied only to the rear wheels.
Charge Monitor
This switch is present in all instrument panels, but is
The charge monitor (32) indi- inactive in trucks without this option.
cates an abnormality in the
charging system while the engine
is running.
Panel Dimmer Switch
If the monitor lamp lights up,
check the charging circuit. Action The panel dimmer switch (36) is used
code “01” will be indicated. to adjust the brightness of the lighting
inside the monitor panel and pilot
Transmission Oil Filter Monitor lamps.
Refer to Hydraulic
Tank Service in
this section.
FIGURE 2-1. LUBE OIL FILTERS FIGURE 2-2. FILTERS - Upper Left Front of Engine
Upper Right Front of Engine
1. Engine Oil By-Pass 2. Fuel Filters
Filters
Truck Serial Number ________________________
5. AIR DRYERS
Replace air dryer desiccant cartridges. Refer to
Service Manual, Section K for replacement
instructions.
3. FRONT SUSPENSIONS
Drain Front suspension oil. Inspect upper flange
internal bearing. Replace worn parts. Refill sus-
pensions with clean oil and recharge with nitro-
gen. Refer to Service Manual, Section H for
instructions and WARNINGS when servicing
suspensions.
5. RADIATOR
Inspect air-to-air aftercooler for damage. After-
cooler damage may result in air leaks causing
reduced engine performance due to low boost
pressure. Whistling noise due to air leakage
may also be present if aftercooler is cracked.
When removing tank cap, turn cap slowly at first Before raising body, be certain that the truck is in
to relieve inner pressure. Remove cap only after an area where there is sufficient overhead clear-
pressure has been completely relieved. Any ance to allow the body to be raised.
operating fluid, such as hydraulic oil or brake
fluid escaping under pressure, can have suffi- 6. Lower the dump body and shut down the
cient force to enter a person's body by penetrat- engine and repeat steps 2. through 4. if neces-
ing the skin. Serious injury and possibly death sary.
may result if proper medical treatment by a phy-
sician familiar with this injury is not received
immediately.
Filling Instructions (Rear Brake Cooling Oil Sup-
2. Turn the oil filler cap (3, Figure 2-3) slowly ply)
counterclockwise to release internal tank pres-
sure. 1. Park the truck on a level surface, lower the
dump body, and shut down the engine.
Service
1. Remove drain plug (7, Figure 2-8) and drain the
oil from the filter housing. Tighten plug after all
oil is drained.
2. Unscrew filter bowl (4) from head assembly (1).
3. Remove the element and thoroughly clean and
dry all component parts.
4. Coat a new seal (9) with clean engine oil and
install.
5. Install a new element (5) and install the filter
bowl (4) into the head assembly (1).
6. Start the engine and let it idle for 5 minutes.
Stop engine and check for leaks. Check trans-
mission for proper oil level and adjust if neces-
sary.
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .P3-3
COMPONENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .P3-3
Component Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .P3-4
Stage 1.
The injector piston (2) is in its normal or
“rest” position. The discharge chamber (3) is
filled with lubricant from the previous cycle.
Under the pressure of incoming lubricant (6),
the slide valve (5) is about to open the pas-
sage (4) leading to the measuring chamber
(1) above the injector piston (2).
Stage 2.
When the slide valve (5) uncovers the pas-
sage (4), lubricant (6) is admitted to the mea-
suring chamber (1) above the injector piston
(2) which forces lubricant from the discharge
chamber (3) through the outlet port (7) to the
bearing.
Stage 3.
As the injector piston (2) completes its
stroke, it pushes the slide valve (5) past the
passage (4), cutting off further admission of
lubricant (6) to the passage (4) and measur-
ing chamber (1). The injector piston (2) and
slide valve (5) remain in this position until
lubricant pressure in the supply line (6) is
vented.
Stage 4.
After venting, the injector spring expands,
causing the slide valve (5) to move, so that
the passage (4) and discharge chamber (3)
are connected by a valve port (8). Further
expansion of the spring causes the piston to
move upward, forcing the lubricant in the
measuring chamber (1) through the passage
(4) and valve port (8) to refill the discharge
chamber (3).
The injector is now ready for the next cycle.
NOTE
* 10
1
RT R 5 6 7
LS
LT P
28
27
25 29
11
12
26 20 19
13
30 14
A B C D
Tube
18 Hose ( Flange )
Hose ( Low Pressure )
Block
24 23 22 21
Coupling
17 16 15
HH346
May 2000
HD785-5LC
UNIT 224, 228 & UP
Hydraulic Piping
( Steering, Hoist
& Brake Cooling )
®
www.komatsuamerica.com