Troubleshooting - JLG 600SJ Service And Maintenance Manual

Troubleshooting

Item
Check oil level in reservoir Insufficient hydraulic fluid could lead to cavitation that would
and oil supply to the motor. cause system noise.
Air trapped within the system lines, or the motor itself, could
Check for air in the system.
result in cavitation that would cause system noise.
Inspect the output shaft A loose or incorrect shaft coupling will produce vibrations
couplings. that could result in system noise.
Inspect the output shaft Misaligned shafts create excessive frictional vibration that
alignment. could result in system noise.
Hydraulic oil viscosity Viscosity above acceptable limits will result in cavitation that
above limits. would lead to system noise.
Item
Check oil level in reservoir Insufficient amount of hydraulic fluid will not meet the cool-
and oil supply to the pump. ing demands of the system.
Inspect the heat exchanger, If the heat exchanger fails, or becomes obstructed, it may
(if so equipped). not meet the cooling demands of the system.
If a system relief valve becomes unseated for an extended
Check the system relief
period of time or fails for any other reason, the system could
valves.
become overheated.
Item
Obstructed or restricted flow through the servo control sig-
Check the signal line to the
nal lines could result in slow shift or no shift conditions
servo control port.
within the motor.
Check that the correct sup-
Supply and drain orifices determine the shift rate of the
ply and drain orifices are
motor. The smaller the orifice, the longer the time it takes to
properly installed, and are
shift the motor. Obstruction will also increase shift times.
not obstructed.
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Table 3-3. Excessive Noise and/or Vibration
Description
Table 3-4. System Operating Hot
Description
Table 3-5. Won't Shift or Slow to Start
Description
– JLG Lift –
SECTION 3 - CHASSIS & TURNTABLE
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 prop-
erly 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 necessary.
Repair or replace any malfunctioning relief valves as appli-
cable and verify that the loads on the machine are not exces-
sive.
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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