JLG 534D-10 - Manual (Page 132)

Hydraulic System
8.8 534D-9, 534D-10 & 544D
5. If the proper pressure cannot be set, use the
accompanying hydraulic schematic, electrical
schematic, and/or Section 6.6, “Hydrostatic Drive
Performance Checks,” to help correct the problem.
g. Service Brake Pressure
1. Start the machine and warm the hydraulic system to
operating temperature.
2. Shut off the machine and install a digital or a
1000 psi (69 bar) gauge to the test port located at
the top center of the front axle. Make sure the gauge
can be observed from the operator’s cab.
3. Start machine and switch OFF park brake.
4. Depress brake pedal as far as possible to obtain
maximum service brake pressure. The gauge should
read 638 psi +/- 50 psi (44 bar +/- 3,4 bar) at low idle.
h. Adjusting Service Brake Pressure
1. The brake pressure is non-adjustable.
2. If the proper pressure cannot be set, use the
accompanying hydraulic schematic, electrical
schematic, to help correct the problem.
i. Main Control 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 test port located at
the left side in front of the return filter.Make sure the
gauge can be observed from the operator’s cab.
3. Start the machine, leave the park brake applied.
4. Running the engine at high idle, bottom the extend/
retract cylinder. The gauge should read 3100 psi +
200 /- 0 psi (213,7 bar +13,8/-0 bar) 534 D-9/10,
3500 psi + 200 /- 0 psi (241 bar + 13,8/-0 bar) 544D.
j. Adjusting Main Control Pressure
1. Shut the machine off. The main relief valve (4) is
located at the right rear corner of the main control
valve.
2. 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, run
the engine at high idle and bottom the extend retract
cylinder. The gauge should read 3100 psi + 200 /- 0
psi (213,7 bar +13,8/-0 bar) 534 D-9/10, 3500 psi +
200 /- 0 psi (241 bar + 13,8/-0 bar) 544D.
4. If the proper pressure cannot be set, use the
accompanying hydraulic schematic, electrical
schematic, and/or the troubleshooting guide to help
correct the problem.
k. Tilt, Sway and Auxiliary Pressures
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 (689 bar) psi gauge to the test port located at
the left side in front of the return filter.Make sure the
gauge can be observed from the operator’s cab.
3. Start the machine, leave the park brake applied, run
the engine at low idle and bottom the individual
section in both directions. The gauge should read
3250 psi + 100 /- 0 psi (224 bar +6,9/-0 bar)
534D-9/10, 3000 psi + 100 /- 0 psi (207 bar +6,9/-0
bar) 544D for the tilt section and the sway section.
The auxiliary section should read 2000 psi +/-100 psi
(138 bar +/- 6,9 bar).
l. Adjusting Tilt, Sway and Auxiliary Pressures
1. Shut the machine off. The relief valves (5) are
located at each end of the valve sections from the
left side in at main control valve.
2. 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, run
the engine at low idle and bottom the individual
section in both directions. The gauge should read
3250 psi + 100 /- 0 psi (224 bar +6,9/-0 bar)
534D-9/10, 3000 psi + 100 /- 0 psi (207 bar +6,9/-0
bar) 544D for the tilt section and the sway section.
The auxiliary section should read 2000 psi +/-100 psi
(138 bar +/- 6,9 bar).
4. If the proper pressure cannot be set, use the
accompanying hydraulic schematic, electrical
schematic, to help correct the problem.
MX1140
AUX
SWAY
TILT
CROWD
HOIST
4
5 5