JLG 45e ANSI Service Manual - Manual (Page 80)

SECTION 3 - TROUBLESHOOTING
3-4 – JLG Lift – 3120743
Table 3-2.Boom Assembly - Troubleshooting
TROUBLESHOOTING CHART
TROUBLE PROBABLE CAUSE REMEDY
CONTROL VALVES.
Valve spool sticking.
Dirt in oil causing excessive temperature build-
up. Flush system and change oil using recom-
mended viscosity
Moisture in oil. Flush system and change oil using recom-
mended viscosity
Incorrect valve mounting causing warping of the
unit. Loosen valve and check mounting.
Repair as necessary.
Valve spool scored. Remove valve and repair or replace as neces-
sary.
Tie-bolts in valve over torqued. Correctly torque bolts.
Return spring weak or broken. Remove valve and repair or replace as neces-
sary.
Relief valve malfunctioning causing excessive
pressure within valve. Check pressure delivery to and from valve and
repair or replace as necessary.
Valve leaking.
Dirt or other foreign material under seal. Remove and repair valve as necessary.
Valve spool scored.
Remove valve and repair or replace as
necessary.
Excessive back pressure caused by restricted
return line to reservoir.
Remove line and clear obstruction or replace
line as necessary.
Damaged valve seals.
Remove valve and repair or replace as
necessary.