HYDRAULIC SYSTEM RT880E SERVICE MANUAL
2-14 Published 11-10-2014, Control # 524-00
Pump No. 1 Troubleshooting
Symptom Probable Cause Solution
1. Oil Leakage a. Hose fittings loose, worn or damaged a. Check and replace damaged fittings
or O-rings.
b. Oil seal rings deteriorated by excess
heat.
b. Replace oil seals by disassembling
pump. Contact Manitowoc Crane
Care for instructions, or refer to
Volume 2 of the Service Maintenance
Manual
c. Bolt loose or its sealing area
deteriorated by excess heat.
c. Loosen bolt, then torque, or replace
bolt.
d. Shaft seal worn or damaged. d.
NOTE: Check fluid leaking from housing
weep hole to better determine which
seal has failed. If pump is leaking
hydraulic fluid, the inboard seal has
failed. If the pump is leaking
transmission fluid, the outboard seal
has failed.
- Remove seal carrier from pump
- Remove damaged seal
- If shaft is worn, install new seal
- Reinstall seal carrier
2. No flow from
pump (if pump
does not prime in
30 seconds,
STOP)
a. Pump not installed correctly. a. Check proper drive rotation. Make
sure pump shaft is turning (i.e. drive
coupling is engaged). Check for
sources of suction leaks. Check that
inlet flange is tight. Check for pinched
O-rings.
b. Pump not getting oil. b. Make sure reservoir is at proper level.
3. Pump does not
build pressure.
a. Flow has an unrestricted path a. Check for open circuit to reservoir.
4. Pump only builds
a few hundred PSI
290 to 435 psi (20
to 30 bar)
a. Pump control settings too low a.
- Check if compensator is backed out
- Check for load sense pressure signal
- Check that system relief valve is
vented
b. Control is malfunctioning b. Make sure orifices are not plugged
and that control spools/springs are
assembled correctly.
c. Internal leakage in cylinders, valves,
motors, or pumps.
c. Repair component
5. Pump won’t
compensate
a. Control is malfunctioning. a. Clean orifices in control of
contamination. Confirm orifice and
plugs are properly assembled.
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