JLG 150HAX ANSI Service Manual - Manual (Page 139)

SECTION 6 - SCHEMATICS
3120679 – JLG Lift – 6-11
Difficulty encountered when moving machine.
Load capacity exceeded. Reduce load. Apply loads only in accordance
with load capacity indicator.
Machine being moved up too steep a grade. Remove machine from grade and check that
drive system operates correctly.
Grade too steep. See Caution Placard on platform for specified
grades and sideslopes.
Drive wheel tire treads worn smooth. Replace tires as necessary and inflate to speci-
fied pressure.
System pressure too low. Re-adjust pressure.
DRIVE SYSTEM.
No response to control.
Hydraulic system oil low. Replenish oil as necessary.
Hydraulic pump not functioning
properly. Repair or replace pump.
Restricted or broken pump supply line. Clean, repair or replace line.
Restricted or broken line on valve bank or rotary
coupling. Clean, repair or replace line.
Rotary coupling leaking internally. (Seals worn.) Repair or replace coupling.
Drive motor(s) not functioning properly. Repair or replace motor(s).
Air in wheel brake circuit. Bleed circuit, determine and correct cause.
Damaged wiring on control switch. Repair or replace wiring.
Control lever not functioning properly. Replace lever.
Brake(s) not releasing. Determine cause and repair or replace.
Machine drives erratically.
Microswitch on controller improperly adjusted. Adjust microswitch on controller for proper oper-
ation.
Table 6-4.Chassis - Troubleshooting
TROUBLE PROBABLE CAUSE REMEDY