Troubleshooting - JLG 600A Service And Maintenance Manual

SECTION 3 - CHASSIS & TURNTABLE

Troubleshooting

Item
Check oil level in reservoir and oil Insufficient hydraulic fluid could lead to cavitation that would cause sys-
supply to the motor. tem noise.
Check for air in the system. Air trapped within the system lines, or the motor itself, could result in cavi-
tation that would cause system noise.
Inspect the output shaft cou- A loose or incorrect shaft coupling will produce vibrations that could result
plings. in system noise.
Inspect the output shaft align- Misaligned shafts create excessive frictional vibration that could result in
ment. system noise.
Hydraulic oil viscosity above limits. Viscosity above acceptable limits will result in cavitation that would lead
to system noise.
Item
Check oil level in reservoir and oil Insufficient amount of hydraulic fluid will not meet the cooling demands
supply to the pump. of the system.
Inspect the heat exchanger, (if so If the heat exchanger fails, or becomes obstructed, it may not meet the
equipped). cooling demands of the system.
Check the system relief valves. If a system relief valve becomes unseated for an extended period of time or
fails for any other reason, the system could become overheated.
Item
Check the signal line to the servo Obstructed or restricted flow through the servo control signal lines could
control port. result in slow shift or no shift conditions within the motor.
Check that the correct supply and Supply and drain orifices determine the shift rate of the motor. The smaller
drain orifices are properly the orifice, the longer the time it takes to shift the motor. Obstruction will
installed, and are not obstructed. also increase shift times.
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Table 3-6. Excessive Noise and/or Vibration
Description
Table 3-7. System Operating Hot
Description
Table 3-8. Won't Shift or Slow to Start
Description
Action
Fill the reservoir to the proper level and ensure that oil supply to the motor
is adequate and the lines are unobstructed.
Ensure that all of the system lines and components are purged of air.
Ensure that the correct coupling is used and that it fits properly onto the
shaft.
Ensure that the shafts are properly aligned.
Replace hydraulic oil with appropriate fluid for operating conditions.
Action
Fill the reservoir to the proper level.
Ensure that heat exchanger is receiving adequate air flow and that the
heat exchanger is in good operating condition. Repair or replace as neces-
sary.
Repair or replace any malfunctioning relief valves as applicable and verify
that the loads on the machine are not excessive.
Action
Ensure that the signal lines are not obstructed or restricted and that signal
pressure is adequate to shift the motor.
Ensure that the proper control orifices are installed in the motor and verify
that they are not obstructed. Clean or replace as necessary.
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