Pump Service Manual
XD5-100-A1
Phone: (402) 727-9700
Website: www.Oilgear.com
905 S. Downing Street, Fremont, NE 68025
Page 22 of 31
Issue Date: 1/4/2021
910003
8
Troubleshooting
Problem
Causes
Remedy
Unresponsive
or Sluggish
Control
The Saddle Bearings are worn or damaged
Refer to referenced control instruction material.
Inspect bearings, replace if necessary.
Insufficient
Pump
Volume
The delivery limited by a faulty control.
Refer to referenced control instruction material.
Obstructed suction circuit or insufficient supercharge volume.
Inspect for obstruction and verify supercharge.
Insufficient drive motor speed.
Refer to appropriate power material.
Worn or grooved cylinder barrel and/or valve plate mating
surfaces.
Inspect components. Replace as necessary.
Worn piston/shoe assemblies or piston bores in cylinder.
Worn or damaged piston shoe or swashblock.
Irregular or
Unsteady
Operation
Faulty control.
Inspect components. Replace as necessary.
Refer to referenced pump instruction materials.
Fluid level in reservoir is low or supercharge is insufficient.
Verify fluid level and/or supercharge.
Air entering hydraulic system.
Inspect system for leak.
Worn axial piston pump.
Inspect components. Replace.
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 and/or valve plate mating
surfaces.
Worn piston/shoe assemblies or piston bores in cylinder.
Faulty output circuit components.
Excessive or
High Peak
Pressure
Faulty output circuit components.
Check the relief valve.
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.
Inspect system for leak.
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.
Inspect components. Replace.
Pump rotating in wrong direction.
Inspect operation direction of pump.
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 and/or valve plate 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.
