JLG 534D-10 - Manual (Page 131)

8.7 534D-9, 534D-10 & 544D
Hydraulic System
Note: High idle may be needed to allow the steering to
bottom against the steering stop.
5. With the engine running at low idle, turn the steering
wheel into the steering stop. The gauge should read
2500 psi +/- 100 psi (172 bar +/- 6,9) 534D-9/10,
3000 psi +/- 100 psi (207 bar +/- 6,9) 544D.
Note: Do not stall the steering orbitrol valve for more
than 10 seconds as to not allow an excessive amount of
heat buildup.
d. Adjusting Steering Pressure
1. Shut the machine off. The steering valve relief is
located in the top rear of the flow divider valve at the
left inside rear of the frame.
2. Remove the hose and fitting (1) from the flow divider.
3. The relief adjustment is located in the port. Using an
allen wrench, turn the relief clockwise to increase
pressure or counter-clockwise to decrease pressure.
4. Replace the fitting and hose.
5. Start the machine and turn the steering wheel
against the stop. If the reading is not correct, repeat
steps 2, 3, 4 and 5.
6. If the proper pressure cannot be set, use the
accompanying hydraulic schematic, electrical
schematic, to help correct the problem.
e. Hydrostatic Drive Pressure.
1. Start the machine and warm the hydraulic system to
operating temperature.
2. Shut off the machine and install a digital or a
10,000 psi (689 bar) gauge to the bottom test port
(Ma)(2) located at the left side of the hydrostatic
drive pump. Make sure the gauge can be observed
from the operator’s cab.
3. Start the machine, leave the park brake applied and
make sure the 2WD/4WD switch is in the 2WD
position.
4. Engage the shift lever to the forward position and run
the engine at high idle. The gauge should read
6300 psi + 200 /- 100 psi (434 bar +13,8/-6,9 bar).
Note: Do not stall the drive pump for more than
10 seconds as to not allow an excessive amount of heat
buildup.
f. Adjusting Hydrostatic Drive Pressure
1. Shut the machine off. The POR relief valve (3) is
located at the top right of the hydrostatic drive pump.
2. Remove the plastic tamper proof cap, loosen the jam
nut on the relief valve and using an allen wrench;
turn the relief clockwise to increase pressure or
counter-clockwise to decrease pressure.
3. Start the machine, leave the park brake applied and
make sure the 2WD/4WD switch is in the 2WD
position, engage the shift lever to the forward
position. If the reading is within specification, shut
the machine off, install the tamper proof cap and
remove the gauge from the test port.
4. Install the gauge to the top test port (Mb) and repeat
step 3.
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MX1050
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