JLG 534D-10 - Manual (Page 138)

Hydraulic System
8.14 534D-9, 534D-10 & 544D
8. Label, disconnect and cap the hydraulic hoses
attached to the pump.
9. Remove the two bolts and two lockwashers (1)
securing the pump to the engine. Remove the o-ring
located between the engine and the pump. Wipe up
any hydraulic oil spillage.
Note: DO NOT disassemble the operating pump. The
pump is pre-set from the manufacturer. Any adjustments
or repairs performed by anyone other than an authorized
dealer could void the warranty.
b. Pump Installation
1. Place the pump and a new, oiled o-ring into position
on the engine. Align the pump shaft with the internal
engine gear, so that the machined teeth mesh
together.
2. Align the bolt holes with the pump mount holes.
Secure the pump to the transmission with the two
bolts and washers.
3. Uncap and connect the previously labeled hydraulic
hoses to their appropriate locations.
4. Fill the hydraulic reservoir. Refer to Section 8.5.2,
“Hydraulic Oil Reservoir Filling.”
5. Prime the pump by filling the case drain port with fresh,
filtered hydraulic oil from a clean container before
installing the case drain connector and hose.
6. Check all routing of hoses and tubing for sharp
bends or interference with any rotating members. All
tube and hose clamps must be tight.
7. Start the engine and run at approximately one-third
to one-half throttle for about one minute without
moving the machine or operating any hydraulic
functions.
8. Inspect for leaks and check all fluid levels. The
hydraulic reservoir oil level must be to the middle of
the sight gauge.
c. Pump Test
Refer to Section 8.3.1, “Pressure Checks and
Adjustments.”
1. Check the system functions.
8.7 DRIVE MOTORS
8.7.1 Front Drive Motor
The front drive motor is mounted to the carrier of the front
drive axle and powers the machine in 2WD and 4WD.
a. Front Drive Motor Removal
1. Park the machine on a firm, level surface, level the
machine, fully retract the boom, raise the boom to
access drive motor, place the transmission control
lever in (N) NEUTRAL, engage the park brake and
shut the engine OFF.
2. Place a Do Not Operate Tag on both the ignition key
switch and the steering wheel, stating that the
machine should not be operated.
3. Open the engine cover and the hydraulic oil
reservoir/fuel tank cover. Allow the system fluids to
cool.
4. Remove the deck cover and disconnect the battery
negative (-) cable from the battery negative (-)
terminal.
5. With the engine OFF, relieve any trapped pressure in
the hydraulic system.
6. Thoroughly clean the drive motor and surrounding
area, including all hoses and fittings, before
proceeding.
7. Place a suitable container to catch hydraulic fluid
drainage beneath the frame.
Note: Cap all hoses as you remove them to prevent
unnecessary fluid spillage.
8. Label, disconnect and cap all the hydraulic hoses
attached to the drive motor. Cap all fittings and
openings to prevent dirt and debris from entering the
hydraulic system.
9. Wipe up any hydraulic fluid spillage in, on, near and
around the machine and the work area.
10. Loosen and remove the four bolts holding the drive
motor to the carrier housing.
11. Pull the drive motor back from the axle carrier and
place on a suitable support or table.
Ma
Ps
Mb
S
T 2
G
MX1150
1