Boom assembly - troubleshooting -5 – JLG 45e Service Manual User Manual
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SECTION 3 - TROUBLESHOOTING
3120861
– JLG Lift –
3-5
Table 3-2.BOOM ASSEMBLY - TROUBLESHOOTING
TROUBLESHOOTING CHART
TROUBLE
PROBABLE CAUSE
REMEDY
LOWER LIFT FUNCTION.
If the lower boom assembly does not fully lower.
The Mid and Lower Booms are out of synchroni-
zation.
Refer to synchronize procedure.
MAIN TELESCOPE SYSTEM.
No response to telescope control.
Telescope control switch inoperative.
Repair or replace control switch.
Hydraulic system oil low.
Replenish oil as necessary.
Damaged wiring on control switch or solenoid
valve.
Repair or replace wiring.
Control valve not functioning properly.
Repair or replace valve.
Restricted or broken supply line on valve bank or
hydraulic pump.
Clean or replace line.
Telescope cylinder not functioning properly.
Repair or replace cylinder.
Hydraulic pump not functioning properly.
Repair or replace pump.
Boom will not extend.
Control valve not functioning properly.
Repair or replace control valve.
Restricted or broken hydraulic line or fitting.
Clean, repair, or replace line or fitting.
Pressure setting incorrect.
Check pressure/re-adjust as necessary.
Telescope cylinder not functioning properly.
Repair or replace cylinder.
Boom extends and retracts erratically.
Hydraulic system oil low.
Replenish oil as necessary.
Wear pads worn.
Replace pads as required.
Restricted or broken hydraulic line or fitting.
Clean, repair, or replace line or fitting.
Control valve not functioning properly.
Repair or replace valve.
Worn seals in telescope cylinder.
Replace seals.
Cylinder not functioning properly.
Repair or replace cylinder.
Distorted boom section(s).
Replace distorted section(s).
Counterbalance valve not functioning properly.
Replace counterbalance valve.