Troubleshooting Guides - Manitowoc Grove 5540F Service Manual

5540F/YB5515 SERVICE MANUAL

TROUBLESHOOTING GUIDES

Table 4-1
General Hydraulic System Troubleshooting
Problem
Noise (above normal).
Slow operating speeds (All functions).
No movement when system is first
started.
Loss of movement during operation.
GROVE
Possible Cause
Air in system.
Low oil supply.
Restriction in pump inlet line.
Dirty oil.
Loose clamps, vibration of hydraulic
lines.
Dirt or foreign material in a relief valve.
Broken control valve spool.
Pump bearings worn.
Low engine rpm.
Air leak in pump inlet line.
Air in oil (foam in tank).
Leakage in the load sense relief valve.
Improper load sense relief valve
setting.
Leakage in hydraulic swivel.
Control valve not fully actuated.
Improper primary pump.
Faulty pump.
Low oil level.
Air or restriction in inlet line to pump
pressure.
Cold oil or wrong weight of oil.
Low oil level.
Vacuum in hydraulic tank.
Restriction or leakage in the relief
valve.
Broken hydraulic line.
Bad seal in hydraulic swivel.
Broken gear or shaft in pump.
Published 10-21-2010, Control# 198-04
HYDRAULIC SYSTEM
Remedy
With engine at low rpm, operate
all control functions several times
to return the air to atmosphere
through the tank breather.
Add recommended oil.
Remove and clean inlet line to
pump.
Change oil and filters. See
Preventative Maintenance, Chapter 5.
Check and tighten.
Clean or replace the relief valve.
Replace the control valve section.
Replace the bearings or pump.
Increase engine rpm.
Tighten pump inlet line. Replace O-ring
in inlet flange.
Check oil level, look for leaks in
the system.
Remove and clean or replace the
relief valve.
Replace the relief valve.
Replace seals on swivel shaft.
Check spool travel.
Check and adjust pump pressure
settings. See Main Control Valve.
Overhaul or replace pump.
Check and add oil.
Check and tighten inlet line. Clear
restriction.
Use correct oil, follow normal
warming procedure.
Check and add oil.
Clean tank filler/breather cap.
Clean or replace the relief valve.
Replace.
Replace seals.
Overhaul or replace.
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