Case 580ST, Operator'S Manual

Page: 386 / 434

8 - TROUBLESHOOTING
Hydraulic pump
PROBLEM POSSIBLE CAUSE CORRECTION
Worn or damaged pump gears or
pressure plates.
Make a hydraulic pump performance
test.
Aeration: air entering the systems at:
suction tube, pump shaft, fittings or
cylinder ring nuts. Make a hydraulic pump performance
test.
Cavitation: system restrictions in the
suction line or in the tank filter. Make a visual check and/or a
hydraulic pump performance test.
Water in the system. Check for possible leaks and
eliminate them.
The system relief valve vibrates. Check the system relief valve; adjust
and overhaul, if necessary.
Vibrations in the lines. Visually check.
Cold hydraulic oil. Check the hydraulic oil operating
temperature.
Noisy system.
Wrong oil type. Change the hydraulic oil.
Tank overfilled. Check the hydraulic oil level.
Aeration: air entering the system at:
suction tube, pump shaft, fittings or
cylinder ring nuts. Make a hydraulic pump performance
test.
Hydraulic oil drain through tank
breather.
Cavitation: Restriction of the suction
filter in the tank. Make a visual check and/or a
hydraulic pump performance test.
Low oil quantity. Fill the tank.
Contaminated oil. Drain the tank and refill with clean oil.
Too high/low setting of the relief valve. Drain the tank and refill with clean oil.
Test relief valves.
Oil in system too light. Drain the tank and refill with oil with
the correct viscosity.
Oil heating.
Oil cooler fins obstructed. Clean the oil cooler.
Oil leaks through the shaft seal. Worn shaft seal. Replace the shaft seal and inspect
the pump.
Low oil level. Fill the tank.
Air in the suction system. Check and tighten the suction lines.
Foamy oil.
Wrong oil type. Change the hydraulic oil.
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