22 Owner Service
MAN0450 (10/28/2005)
TROUBLESHOOTING
PROBLEM POSSIBLE CAUSE SOLUTION
Noisy pump caused by cavitation Oil too heavy Change to proper viscosity
Oil filter plugged Replace filter
Suction line plugged or too small Clean line and check for size
Suction line kinked Replace line
Oil heating Oil supply low Fill reservoir
Contaminated oil Drain reservoir, change filter, and
refill with clean oil
Setting of relief valve too high or
too low
Set to correct pressure
Pump operating too fast Do not exceed 540 rpm PTO
speed
Shaft seal leakage Worn shaft seal Replace shaft seal
Foaming oil Low oil level Fill reservoir
Air leaking into suction line Tighten fittings
Wrong kind of oil Drain and refill reservoir with non-
foaming oil
Moisture in oil Keep oil temperature below 180°
and continue to operate as oil
dries out, or replace oil and purge
system if foaming is excessive
Boom drops as dipper or bucket
cylinder lever is activated while
boom control is in raised position
Load check valve leaking Clean or replace check valve
assembly
Jerky operation Hydraulic hoses plumbed
incorrectly
Check hydraulic plumbing
schematic and correct hose
routing as required