Advertisement
2
2
. TROUBLESHOOTING
1)
SYSTEM
Problem
Large fork lowering speed
Slow fork lifting
Hydraulic system makes
abnormal sounds
High oil temperature
C
C
ause
Seal inside control valve defective.
Oil leaks from joint or hose.
Seal inside cylinder defective.
Lack of hydraulic oil.
Hydraulic oil mixed with air.
Oil leaks from joint or hose.
Excessive restriction of oil flow on
pump suction side.
Relief valve fails to keep specified
pressure.
Poor sealing inside cylinder.
High hydraulic oil viscosity.
Mast fails to move smoothly.
Oil leaks from lift control valve spool.
Oil leaks from tilt control valve spool.
Excessive restriction of oil flow pump
suction side.
Gear or bearing in hydraulic pump
defective.
Lack of hydraulic oil.
High oil viscosity.
Oil filter clogged.
6-10
Remedy
Replace spool or valve body.
Replace.
Replace packing.
Add oil.
Bleed air.
Replace.
Clean filter.
Adjust relief valve.
Replace packing.
Change to ISO VG 46.
Adjust roll to rail clearance.
Replace spool or valve body.
Replace spool or valve body.
Clean filter.
Replace gear or bearing.
Add oil.
Change to SAE80W-90LSD, class
API GL-5 gear oil.
Clean filter.
Advertisement
