JLG 400CRT Service Manual User Manual
Page 45
SECTION 3 - TROUBLESHOOTING
3121804
– JLG Lift –
3-3
Counterbalance valve on lift cyl. improp-
rely adjusted or not functioning properly.
Replace valve.
Control valve not functioning properly.
Repair or replace valve.
Worn seals in lift cylinder.
Replace seals.
Lift cylinder not functioning properly.
Repair or replace lift cylinder.
Platform drifts down
Manual lowering valve not functioning
properly.
Repair or replace valve.
Worn seals in lift cylinder.
Replace seals.
Holding valve on lift cylinder not function-
ing properly.
Repair or replace valve.
High Drive does not operate below horizontal
Damaged wiring on limit switch.
Repair or replace wiring.
Damaged limit switch.
Replace limit switch
Table 3-1. Elevation System Troubleshooting
TROUBLE
PROBABLE CAUSE
REMEDY