JLG 45e ANSI Service Manual User Manual
Page 82
SECTION 3 - TROUBLESHOOTING
3-6
– JLG Lift –
3120743
Boom raises and lowers erratically.
Hydraulic system oil low.
Replenish oil as required.
Restricted or broken hydraulic line or fitting.
Clean, repair, or replace line or fitting.
Lack of lubricant on cylinder shafts and/or boom
pivot.
Lubricate as required.
(Refer to Lubrication Chart.)
Counterbalance valve on lift cylinder improperly
adjusted or not functioning properly.
Replace valve.
Control valve not functioning properly.
Repair or replace valve.
Worn seals in lift cylinder.
Replace seals.
Cylinder not functioning properly.
Repair or replace cylinder.
Boom drifts down.
Worn seals in lift cylinder.
Replace seals.
Lower Lift Function.
If the lower boom assembly does not fully
lower.
The mid and lower booms are out of synchroniza-
tion.
Refer to snchronization precedure.
Main Telescope system.
No response to telescope control.
Telescope control switch in operative.
Repair or replace control switch.
Hydraulic system oil low.
Replenish oil as necessary.
Damaged wiring on control switch or solenoid
valve.
Repair or replace valve.
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 funtioning 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 nessary.
Telescope cylinder not functioning properly.
Repair or replace cylinder.
Table 3-2.Boom Assembly - Troubleshooting