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Bulletin 948034A
11
Bulletin 948034A
PUMP SERVICE MANUAL
TROUBLESHOOTING
PROBLEM
CAUSES
REMEDY
Unresponsive or
Sluggish Control
Swashblock saddle bearings (204) worn or damaged.
Refer to referenced control instruction material.
Inspect bearings. Replace.
Insufficient Pump
Volume
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Obstructed suction circuit or insufficient supercharge volume.
Inspect for obstruction and verify supercharge.
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Worn or grooved cylinder barrel (101) and/or valve plate (401)
mating surfaces.
Inspect components. Replace.
Worn piston/shoe assemblies (102) or piston bores in cylinder
(101).
Worn or damaged piston shoe or swashblock (201).
Irregular or
Unsteady Operation
Faulty control.
Inspect components. Replace. Refer to referenced
pump control instruction materials.
Fluid level in reservoir is low or supercharge is insufficient.
Verify fluid level and/or supercharge.
Air entering hydraulic system
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Faulty output circuit components (cylinder, motors, valves or
other related components).
Inspect components. Replace.
Loss of Pressure
Worn piston pump.
Inspect components. Replace.
Worn or grooved cylinder barrel (101) and/or valve plate (401)
mating surfaces.
Worn piston/shoe assemblies (102) or piston bores in cylinder.
Faulty output circuit components.
Excessive or High
Peak Pressure
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Excessive Noise
Pump stopped or started incorrectly under load.
Verify operation procedure of pump.
Low fluid level in reservoir or insufficient supercharge causing
cavitation.
Verify fluid level and/or supercharge.
Air entering hydraulic system
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Fluid too cold or viscosity too high.
Verify fluid temperature and/or type.
Suction line problem i.e.; obstructions in line, line too long, line
diameter too small or too many bends and/or loops in line.
Inspect line for obstruction.
Broken or worn piston/shoe assembly (102).
Inspect components. Replace.
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Excessive Heating
Operating pump above rated or peak pressure.
Verify pump limitations.
Low fluid level in reservoir or insufficient supercharge.
Verify fluid level and/or supercharge.
Air entering hydraulic system.
Inspect system for leak.
Worn piston pump.
Inspect components. Replace.
Worn or grooved cylinder barrel (101) and/or valve plate (401)
mating surfaces.
Faulty output circuit components (continuous blowing relief valves
or "slip" through valves, cylinder or other components.
Insufficient cooling provision or clogged coolers.
Inspect for obstruction.
