Cat E5000 07
Cat E5000 07
Cat E5000 07
Hydraulic System
Description
Schematic for Trucks
1. Hydraulic tank 4. Steer gear 7. Down safety valve 10. Steering cylinder
2. Hydraulic lift pump 5. Main control valve 8. Lift cylinder
3. Steer pump 6. Flow regulator valve 9. Tilt cylinder
General Information
The hydraulic pump draws oil from the oil tank
and delivers it to the main control valve, which dis-
penses it for lift and tilt functions.
The steer gear and steer pump are covered in the
STEERING SYSTEM section and the steering
cylinder is covered in the REAR AXLE section.
99759-8B110
7.1
NOTES
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99759-7B110
7.2
SCHEMATIC(S) INSERTION
Schematic(s) name/number
99759-7B110
7.3
HYDRAULIC SYSTEM
Hydraulic Tank
1
6 5
4
3 8609093
General Information
The tank contains internal filtering means including
a strainer on the suction line and a filter on the
return line.
The lift cylinder return pipe allows the cylinders to
draw fluid when they retract, providing the bore
walls with oil which inhibits corrosion.
99759-8B110
7.5
HYDRAULIC SYSTEM
Hydraulic Pump
8609094A
General Information
This gear pump is capable of developing very high
pressure on its discharge side. A special arrange-
ment is incorporated in the pump construction for
the purpose of keeping the side clearances mini-
mized between bushings on the one side and
pump gears on the other. Note, in illustration
203585 (page 7.6), that discharge pressure is
applied to the back of each bushing through inter-
nal oilways.
99759-8B110
7.6
HYDRAULIC SYSTEM
Drive Gear
203585
Discharge side
200333
99759-8B110
7.7
HYDRAULIC SYSTEM
Control Valve
9 8 7
10
14
2 6
3 6
11
12 13
Sequence
1. Inlet / Unloader Spool 8. From Hydraulic Pump
2. Tilt Spool 9. To Tank
3. Auxiliary Spool 10. Main Relief Valve, Auxiliary Valve (back)
4. Auxiliary Attachment Spool 11. Auxiliary Relief Valve (front)
5. Outlet Spool 12. Tie bolt
6. Flow Control Screws 13. Nut
7. Lift Port 14. Switches
General Information
The control valve consists of three valve blocks, all
spool-type. The spools are finished by lapping for
their respective blocks and their combination
should not be changed. The lift valve assembly has
a built-in load check valve. The tilt valve spool has
a built-in tilt lock valve. The attachment valve
assembly has a built-in overload relief valve.
99759-8B110
7.8
HYDRAULIC SYSTEM
200345
205979
General Information
The left and right lift cylinders are single-acting
type.
The left and right tilt cylinders are double-acting
type. The piston rod carries a screw-on socket.
The socket is repositioned as necessary by turn-
ing when the cylinder is connected to the outer
mast. This feature allows the tilt cylinders to move
in unison.
The tilt angle is increased or decreased with the
spacer and shim of each cylinder.
99759-8B110
7.9
HYDRAULIC SYSTEM
Burst
General Information
The down safety valve is built in the oil pipe joint at
the bottom end of the lift cylinder. This valve is
internally provided with an orifice to prevent shock
when the valve is closed. In the valve having no ori-
fice, the oil leaks around the valve to prevent
shock.
Valve Types
Down safety valves are available in six types differ- a
ing in terms of shutoff flow and identified by the
number punched on the flat (indicated as “a” on
illustration 201731A). The numbers are: 50, 70, 90,
100, 120, and 150. No. 90 and No. 120 valves each
come in two kinds differing in screw thread size. a
E3000 -
EC4000 70 90 70 90 70 Top View: • Dual-stage panoramic lift cylinder
E4000 - • Dual-stage full free-lift panoramic,
EX5000 70 120 70 120 70
E5500 - 1st and 2nd cylinders
E6500 90 90 120 120 90 • Triple-stage full free-lift panoramic,
2nd lift cylinder
Bottom View: • Triple-stage full free-lift panoramic
1st lift cylinder
99759-8B110
7.10
HYDRAULIC SYSTEM
! WARNING
99759-8B110
7.11
HYDRAULIC SYSTEM
Hydraulic Pump
Removal
Sequence
1. Hardware
2. Pump
Start By:
1. Disconnect the battery from the truck. 5. Secure the motor from above with a crane,
hoist, or other adequate device, or support it
2. Disconnect the hoses attached to the pump
at its center with a garage jack.
fittings.
6. Remove the motor and pump assembly from
3. Disconnect the power cables and wire leads
the truck.
from the pump motor.
7. Remove the hydraulic fittings from the pump.
4. Raise the truck enough to allow the pump and
motor assembly to be removed from below the
truck. Make sure that the truck is stable and
secure in the raised position.
99759-8B110
7.12
HYDRAULIC SYSTEM
Installation
1. To install, follow the reverse sequence of the
disassembly procedure. Before installing
hydraulic fittings in the pump, inspect all
O-rings for damage or aging and replace
them as required.
2. Tighten hose to the following specifications.
E3000-EC4000 E4000-E6500
99759-8B110
7.13
HYDRAULIC SYSTEM
Disassembly
Standard Pump (1 ton)
5
3
1
4
7
9
6
Sequence
1. End cover 4. Shaft seal and retainer ring 7. Drive shaft
2. O-ring, bush seal, and 5. O-ring, bush seal, and 8. Gear pack
back-up seal back-up seal 9. Body and rear bushes
3. Flange 6. Front bushes
99759-8B110
7.14
HYDRAULIC SYSTEM
Disassembly
Standard Pump (2/3.3 ton)
1 5
9
4
7
6
Sequence
1. End cover 4. Shaft seal and retainer ring 7. Drive shaft
2. O-ring, bush seal, and 5. O-ring, bush seal, and 8. Gear pack
back-up seal back-up seal 9. Body and rear bushes
3. Flange 6. Front bushes
Start By:
Externally clean the pump to make sure that it is free
of all matter that may contaminate the pump parts
during disassembly, inspection, or reassembly.
99759-8B110
7.15
HYDRAULIC SYSTEM
8609101
8609100
8609102
99759-8B110
7.16
HYDRAULIC SYSTEM
8609103
8609104
99759-8B110
7.17
HYDRAULIC SYSTEM
Inspection after Disassembly 3. The bush bearing liners are acceptable if they
are not scored or do not show other damage.
Body The general outside area of the bush should
not show any prominent signs of wear.
1. Inspect the body bore cut-in where gears wipe
into the body. Gears
2. The body can only be reused if the cut-in is
1. The gear side faces should be examined for
bright and polished in appearance and the
bushing or scoring. Often operation on con-
depth does not exceed .08 mm.
taminated fluid shows scoring between the
3. The body should be replaced if the surface is root of the gear and the journal, which leaves
scored, has a matte appearance, or shows a wear step. If a wear step can be felt, coinci-
signs that the tips of the gears have dug in dental with the root diameter, by drawing a
and torn away the surface material. sharp-pointed tool across the surface from the
4. The body should be inspected to ensure that journal outward towards the tip of the gear,
there is no superficial damage which may then the gear must be replaced.
adversely affect performance or sealing. Pay 2. The gear teeth should be carefully examined
particular attention to the port threads and to ensure that there are no signs of bruising or
body O-ring seal recesses. pitting.
3. The journal bearing surfaces should be com-
Mounting Flange Face
pletely free from scoring or bruising. The sur-
1. The inner surfaces should be inspected to face should be highly polished and smooth to
ensure that there is no unusual wear or scoring the touch.
in the regions where the body O-rings and bush
4. Examine the area where the shaft seal lips run
seals contact, which could result in external leakage.
on the drive shaft. This shows up as polished
2. Check the shaft seal recess for scoring or dam- ring or rings. If a noticeable groove can be felt,
age that could result in oil leakage around the or if there is scoring, the shaft should be
outer diameter of the shaft seal. A replacement replaced.
shaft seal can be refitted with Loctite hydraulic
5. Examine drive keyway in driveshaft journal
sealant to overcome slight damage in this area.
extension to ensure it is not damaged or
chipped.
Bushes and Balance Plate
6. If the driveshaft is not damaged from the drive
1. The side faces which abut the gears should be coupling and the gears have not been harmed
perfectly flat and show no signs of scoring. as described above, then the gears can be
Characteristically there are bright polished reused. If the gears are damaged, they must
areas on this surface caused by loading be replaced as a matched set.
against the gear side faces. This is often more
pronounced on the low-pressure side. These 7. As a matter of good practice, when pumps
should be replaced if there is any general have been dismantled, all the seals should be
scoring or fine scoring with a matte appearance replaced.
or tearing of the surface material.
2. Often, the tips of the opposing gears have
wiped an overlap in a half-moon shape. There
must be no noticeable wear step as it is criti-
cal that the bush side face and balance plate
are completely flat to the gear side face.
99759-8B110
7.18
HYDRAULIC SYSTEM
Reassembly
Trucks with Standard Hydraulic Pump
5
3
1
4
7
9
6
Sequence
1. End cover 4. Shaft seal and retainer ring 7. Drive shaft
2. O-ring, bush seal, and 5. O-ring, bush seal, and 8. Gear pack
back-up seal back-up seal 9. Body and rear bushes
3. Flange 6. Front bushes
Start By:
Ensure that all parts are perfectly clean. Lubricate
the bushes and gears with clean hydraulic fluid.
Ensure that the O-ring recess and end faces of the
body remain dry. This will assist the assembly of
the components with the body bores.
99759-8B110
7.19
HYDRAULIC SYSTEM
Cusp
Removal
Inlet 8609109
Position of
driveshaft
Counterclockwise Rotation
8609108
99759-8B110
7.20
HYDRAULIC SYSTEM
8609112
Premium pump configuration 1. Fit a new shaft seal into the recess in the
mounting flange with the “garter” spring facing
into the pump.
2. If the seal recess was scored, then Loctite
hydraulic sealant must be applied to the outer
diameter of the seal.
3. Apply a coat of high-melting-point grease to
the shaft seal lips.
4. Reinstall the retaining ring. Ensure that it is
located in its groove.
8609102
8609111
99759-8B110
7.21
HYDRAULIC SYSTEM
End
cover
8609115A
8609113
Reassembling the Rear O-ring and Seals E3000 - EC4000 E4000 - E6500
1. Hold the whole unit together and carefully turn 4.7 to 5.2 kgf•m 9.0 to 10.4 kgf•m
it over. Ensure that it is supported on the Tightening torque (34 to 38 lbf•ft) (65 to 75 lbf•ft)
mounting flange, not the driveshaft. for bolts [46 to 51 N•m] [88 to 102 N•m]
2. Remove the end cover and install a new O-
ring, bush seal, and backup seal.
NOTE
8609114
99759-8B110
7.22
HYDRAULIC SYSTEM
Pressure
Test gauge
unit Micronic Variable
filter restrictor
Flow
Strainer Relief meter
Tank
valve
8609116
99759-8B110
7.23
HYDRAULIC SYSTEM
99759-8B110
7.24
HYDRAULIC SYSTEM
99759-8B110
7.25
HYDRAULIC SYSTEM
Disassembly
99759-8B110
7.26
HYDRAULIC SYSTEM
Suggestions Reassembly
Main Relief Valve Before Reassembly:
1. Wash all parts except for O-rings with solvent.
NOTE
2. Apply hydraulic oil to O-rings when installing
To remove main relief valve for cleaning or them.
inspection, loosen its plug. Loosening the 3. Make sure that each spool moves freely.
lock nut will disturb the pressure setting.
5 4
1
207068
Sequence
1. Hose guard 4. Cylinder clamp (cushion, collar, and shims)
2. High-pressure hose 5. Lift cylinder and bracket
3. Set bolt and shims
99759-8B110
7.28
HYDRAULIC SYSTEM
Suggestions
1. Removing hose guard:
With the lift bracket raised to the maximum
height, remove each hose guard from the front
side of the mast.
! CAUTION
Be careful not to touch the lift control
lever.
Right-hand cylinder
Left-hand cylinder
204933
99759-8B110
7.29
HYDRAULIC SYSTEM
204935
204934
NOTE Installation
The rod end of either lift cylinder is shim-
Lift Cylinders
adjusted to eliminate the difference in To install, reverse the removal sequence and do
stroke between the cylinders. Before the following steps.
removing the stopper bolts, make a record 1. Extend and retract the lift cylinders several
of the number of shims and the cylinder to times under no-load conditions to expel air
which the shims are fitted. from the cylinder circuits and to make sure the
cylinders move smoothly.
2. Place wood blocks under the inner mast and 2. Check the oil level in the hydraulic tank with
detach the sling. Use blocks strong enough to the oil level gauge.
support the mast. 3. Check that the lift height is correct.
4. After the lift cylinders or piston rods have been
replaced, check for difference in stroke
between the two cylinders (refer to MAST
AND FORKS).
202983
99759-8B110
7.30
HYDRAULIC SYSTEM
Removal
Tilt Cylinders
3
1
206883
Sequence
1. Tilt socket pin (spacer) 3. Cylinder pin (spacer)
2. Rubber hose (O-ring) 4. Tilt cylinder
Start By:
1. Lower the forks all the way and tilt the mast
fully forward.
2. Hitch lifting slings to the top crossmember of
the outer mast by passing them through the
round holes. Take up the weight of the mast
with a hoist.
Suggestions
1. Retracting piston rod:
207085
Remove tilt cylinder pin (item 1), and retract
the piston rod all the way.
2. Disconnecting hoses:
Disconnect hoses (item 2) from the cylinder at
the connectors. Use a container to catch oil
from flowing out of the cylinder. Attach caps to
the connectors of the cylinder to protect the
threads of the connectors and to prevent oil
from flowing out of the cylinder when the cylin-
der is removed.
99759-8B110
7.31
HYDRAULIC SYSTEM
Suggestions
Removing Tilt Socket
Later Version
! WARNING
1
4
2 3 206883
1. Rubber hose
2. Tilt socket pin, bolt, washer
3. Tilt cylinder pin, bolt, washer
4. Tilt cylinder
NOTE
99759-8B110
7.32
HYDRAULIC SYSTEM
Disassembly
Lift Cylinders
5
4
204948
Sequence
1. Bracket assembly 4. Piston rod, snap ring, holder, U-ring, nylon
heel, and piston ring
2. Holder, wiper ring, U-ring and O-ring
5. Cylinder tube
3. Bushing and bearing
Suggestions
Removing Piston Rod
Draw the piston rod out gently, taking care not to
damage the sealing members fitted to the piston.
200349
99759-8B110
7.33
HYDRAULIC SYSTEM
Disassembly
Tilt Cylinders
✱ Parts contained in seal kit
3
✱
1 ✱
✱
✱
1
207050
Sequence
1. Tilt socket, bushing, bolt, washer, nut, and 3. Piston rod, piston seal, and nut
grease fitting
4. Cylinder tube and bushing
2. Bushing, O-ring, dust seal, packing and
buffer ring
NOTE
Suggestions
Removing Bushing
1. Wrap the cylinder with a wad of cloth and hold
it in a vise. Using a wrench, remove the bush-
ing from the cylinder.
2. When removing the bushing from the piston
rod, be careful not to rub the buffer ring, pack-
ing, etc., against the threads of the piston rod.
200351
99759-8B110
7.34
HYDRAULIC SYSTEM
200352
200353
99759-8B110
7.35
HYDRAULIC SYSTEM
Suction Strainer
! WARNING
Check the suction strainer for clogging or damage.
Remove the hydraulic tank filler cap only
after the truck has been stopped and the Return Filter
fill cap is cool enough to remove with your
bare hand. Check the return filter for clogging or damage.
99759-8B110
7.36
HYDRAULIC SYSTEM
Control Valve
External Leakage
1. Check for oil leaks from the joint between 2. Quickly disconnect the oil return hose and
adjacent valve housings sealed by O-ring. start collecting the oil coming out of the valve
2. Check for oil leaks from the scrapers sealed from the oil return port A.
by O-rings.
3. Check for oil leaks from the screw
connections.
Internal Leakage
It is not practical to check the control valve alone
for internal leakage. The correct way to check the
control valve in place under normal operating con-
ditions follows.
The internal leakage to be checked includes leak-
age occurring at the lift spool, tilt spool, tilt lock A
valve, and check valves.
[Test oil temperature: approx. 50°C (122°F)]
Amount of oil collected 500 cc (30.5 cu. in.)
1. Pick up a load equal to the rated capacity. Lift for 15 minutes maximum
it approximately 1 meter (3 ft) high. Tilt the
mast forward 3° - 4° and turn off key.
3. If the tilt cylinders or lift cylinders drift (the mast
tilts forward or the fork lowers) excessively even
3° - 4°
though the amount of oil collected in 15 min-
utes is less than 500 cc (30.5 cu. in.), measure
the internal leakage of each cylinder. (The
measurement is the assembly standard and not
the service limit.)
approx.
1 meter
(3 feet)
203521A
99759-8B110
7.37
HYDRAULIC SYSTEM
B
A
C
99759-8B110
7.38
HYDRAULIC SYSTEM
Basic Hydraulic Switch Adjustments Install switch on Tilt spool or Auxiliary spool per
Install switch on Lift spool per Photo 1. Adjust and Photo 3 centered on spool lobe. Adjust and torque
torque bolts on switches to 7 ± 1 in-lbs [0.79 N•m bolts on switches to 7 ± 1 in-lbs [0.79 N•m ± 0.11
± 0.11 N•m] (0.08 kgf•m ± 0.01 kgf•m). N•m] (0.08 kgf•m ± 0.01 kgf•m).
Photo 1 Photo 3
Switch 2
Switch has
to activate
before
reaching
B
point B (the
top of the
cam).
Switch 2
Photo 2
99759-8B110
7.39
HYDRAULIC SYSTEM
207054
99759-8B110
7.40
HYDRAULIC SYSTEM
Adjusting Method
1. Raise the inner mast, place blocks under the 3. Extend the piston rod and tighten the cylinder
right and left sides of the mast, and lower the stopper bolt. Remove the blocks from under
mast until it rests on the blocks. the inner mast.
4. Slowly lower the inner mast all the way to make
sure that the piston rods move smoothly.
202983
Stopper bolt
Shims
200365
NOTE
99759-8B110
7.41
HYDRAULIC SYSTEM
Testing
Lift Cylinder Drift Test Tilt Cylinder Drift Test
1. Pick up a load equal to the rated value, tilt the 1. Pick up a load equal to the rated value, tilt the
mast to the vertical position, raise the forks 1 mast to the vertical position, raise the forks
to 1.5 m (3.3 to 4.9 ft) and stop the truck. about 50 cm (20 in.) and stop the truck.
2. Scribe a line on the mast column and measure 2. Measure the drift extension of the tilt cylinder
the drift of the lift cylinder (drop for 15 minutes) for (extension) 15 minutes.
206891 207056
E3000 - EX5000 E5500 - E6500 E3000 - EC4000 E4000 - EX5000 E5500 - E6500
Lift cylinder drift 50 (2.0) 40 (1.6) Tilt cylinder drift 22 (0.9) 20 (0.8) 15 (0.6)
(rated load) maximum (rated load) maximum
Unit: mm (in.)/15 min Unit: mm (in.)/15 min
Piping
1. Check each hydraulic circuit for leaks.
2. Check to make sure that each hose is free
from twisting or excessive loops.
99759-8B110
7.42