7399 River Road
Delta, BC, Canada
V4G 1B2
Ph: 604-940-8865
Fax: 604-940-8802
Toll Free: 1-888-879-8855
Troubleshooting - Power Units

Quick reference troubleshooting guide.

Noticeable increase in overall noise level at fittings, pipes, valves and pump or motor. Usually accompanied by erratic operation of actuators in the system.
A) Aeration

B) Cavitation

C) Foaming oil in reservoir
A) Find and repair source of air leak at suction side of pump.

B) Find and repair source of restriction at suction side of pump. Collapsed lines.

C) Check flow velocity in return lines. Analyze hydraulic fluid for proper anti-foam additive. Correct fluid level. Check return line termination above fluid level.
Pump, motor or valves make loud rattling or clanking noise under load when first started up; but noise disappears shortly after.
A) Cold oil is too viscous
A) Warm up the system with a pre-heater. Run system under no load until operating temperature is achieved.
Pump, motor or valves for no apparent reason start making loud rattling or clanking noises (accompanied by erratic operation of actuators).
A) Cavitation

B) Aeration
A) Find obstruction (restriction) in line and correct it. Clean suction filter.

B) Find and repair suction leak. Check fluid level in reservoir.
Single loud "pop" or "clank" repeating at regular intervals in pump or hydraulic motor.
A) Aeration
A) Fill reservoir if low on fluid. Tighten all connections.
Increased noise from pump or hydraulic motor. Usually accompanied by sluggish performance.
A) Worn parts

B) Too thin an oil
A) Replace or repair pump or motor. Flush system to remove wear particles.

B) Check oil temperature. Cooler may need to be added. Check fluid viscosity, if incorrect flush system and refill with proper viscosity fluid. Check for cavitation or aeration; remove restrictions and/or repair air leak.
Increased noise from valves, usually chattering sound, sometimes sticking or erratic performance.
A) Worn spools or orifices

B) Electrohydraulic valve cavitation
A) Replace worn parts or hydraulic valve. Flush entire system to remove wear particles and other contaminants.

B) Check for erratic electronic signals. Replace worn parts or entire valve.
Loud slam travels through hydraulic system (hydraulic shock wave).
A) Sticking part suddenly overcomes the constricting force

B) Sudden closing of directional valve
A) Clean parts to remove varnish and sludge. Check compatibility of fluid with system. flush system thoroughly.

B) Investigate the installation of an accumulator to absorb shock.