STINAR 25781, Operation & Maintenance Manual

Page: 60 / 112

Disabled Passenger Lift DPT-512 | 60
SECTION 2 | SERVICING THE HIGH LIFT TRUCK
TROUBLE PROBABLE CAUSE SOLUTION
Hydraulic System (Refer to Figure 2.2.1)
Hydraulic pump fails
to operate.
Transmission not in park. Put transmission in park.
Parking brake not set. Set the parking brake.
Electrical problem.
See electrical
troubleshooting.
PTO switch not on or
defective.
Turn the PTO switch
on or repair the PTO
or switch as required.
Hydraulic pump
problem. Repair or replace the
hydraulic pump.
Insufficient or no
hydraulic pressure.
Hydraulic pump not
operating.
See above.
Tank shut-off valve
closed.
Open shut-off valve.
Insufficient hydraulic oil
in tank.
Add hydraulic oil.
Leaks in system. Find and repair.
Pressure relief valve
bypassing.
Check for
obstructions. Clean or
replace as required.
Check the system
pressure and adjust
relief valve if needed.
Oil strainer in hydraulic
tank clogged. Remove and clean out
strainer.
High pressure filter
clogged.
Replace filter element.
Return line filter
clogged.
Replace filter element.
Hydraulic tank breather
clogged Check breather and
clean if required.
Directional control valve
problem. Repair or replace
directional valve.
Stabilizer legs will not
extend or retract.
Insufficient or no
hydraulic pressure.
See above.
Defective directional
control valve. Repair or replace
valve.
Defective stabilizer lock
valve. Repair or replace
valve.
Electrical problem.
See Troubleshooting
Electrical System.