JLG 45e ANSI Service Manual User Manual
Page 81
SECTION 3 - TROUBLESHOOTING
3120743
– JLG Lift –
3-5
BOOM ELEVATION SYSTEM.
No response to lift control switch.
Lift control switch inoperative.
Repair or replace control switch.Run systems test
Lift cylinder holding valve inoperative.
Repair or replace holding valve.
Electrical malfunction.
See wiring diagram. Run systems test.
Hydraulic system oil low.
Replenish oil as necessary.
Restricted or broken supply line on valve bank or
hydraulic pump.
Clean or replace line.
Control valve not functioning properly.
Repair or replace valve.
Lift cylinder not functioning properly.
Repair or replace cylinder.
Hydraulic pump not functioning properly.
Repair or replace pump.
Dump valve (bypass) not operating.
Determine cause and repair or replace valve.
Boom will not raise.
Load capacity exceeded (personnel or equip-
ment on platform).
Reduce load.(Refer to capacity placard.)
Hydraulic system oil low.
Replenish oil as necessary.
Electrical failure to valves.
See proper wiring diagram. Run systems test.
Restricted or broken hydraulic line or fitting.
Clean, repair, or replace line or fitting.
Control valve not functioning properly.
Repair or replace valve.
Pressure relief valve not functioning properly.
Re-adjust or replace valve.
Lift cylinder not functioning properly.
Repair or replace cylinder.
Motor/Pump does not respond when LIFT control
switch is moved to UP position.
Refer to Electrical Diagram and/or Electrical Sys-
tem Troubleshooting Chart. Run systems test.
Binding lift cylinder or boom pivot pin.
Repair or replace cylinder or pin.
Bypass valve (dump) not functioning.
Repair or replace valve.
Boom will not lower.
See: Boom will not raise.
Pressure relief valve not functioning properly.
Re-adjust or replace valve.
Holding valve not functioning properly.
Re-adjust or replace valve.
Table 3-2.Boom Assembly - Troubleshooting