JLG 400CRT ANSI Service Manual - Manual (Page 48)

SECTION 3 - TROUBLESHOOTING
3-6 – JLG Lift – 3121111
Machine hard to steer or steering is erratic (cont.)
Lack of lubrication on steer components. Lubricate steer components in accor-
dance with Lubrication Chart.
Restricted crossover relief valve. Clean or replace valve.
Steer system pressure low. Adjust pressure.
Bent steering linkage. Repair or replace linkage as required.
Hydraulic pump not functioning properly. Repair or replace valve.
Steer cylinder not functioning properly. Repair or replace cylinder.
Steering inoperative
Steer switch on controller not functioning
properly. Repair or replace switch.
Hydraulic system pressure too low. Adjust pressure.
Loose or damaged wiring on control
switch or solenoid valve. Ensure proper connection of wires at con-
trol switch or solenoid valve. Using suit-
able test meter, perform continuity test on
wires. Repair or replace wires as neces-
sary.
Solenoid valve not functioning properly. Repair or replace valve.
Restricted or broken hydraulic line on
valve bank or hydraulic pump. Clean, repair or replace line.
Relief valve improperly set or not function-
ing properly. Reset, repair or replace valve as neces-
sary.
Steer cylinder not functioning properly. Repair or replace cylinder.
Machine will not steer left or right
Steer switch on controller not functioning
properly. Replace controller.
Wiring on steer control switch is dam-
aged. Repair or replace wiring.
Wiring on solenoid valve damaged. Repair or replace wiring.
Coil in solenoid damaged. Replace coil.
Bent cylinder rod. Repair or replace cylinder.
Damaged steer linkage. Repair or replace steer linkage.
Machine wanders; steering not firm
Crossover relief valve set too low or not
functioning properly. Reset, repair or replace valve as neces-
sary.
Steer linkage loose. Tighten linkage.
Spindle bushings badly worn. Replace bushings.
Table 3-2. Chassis Troubleshooting
TROUBLE PROBABLE CAUSE REMEDY