Troubleshooting

PROBLEM Noticeable increase in overall noise level at fittings, pipes, valves and pump or motor. Usually accompanied by erratic operation of actuators in the system. Pump, motor or valves make loud rattling or clanking noise under load when first started up; but noise disappears shortly after. Pump, motor or valves for no apparent reason start making loud rattling or clanking noises (accompanied by erratic operation of actuators). Single loud "pop" or "clank" repeating at regular intervals in pump or hydraulic motor. Increased noise from pump or hydraulic motor. Usually accompanied by sluggish performance. Increased noise from valves, usually chattering sound, sometimes sticking or erratic performance. Loud slam travels through hydraulic system (hydraulic shock wave).	PROBABLE CAUSE A) Aeration B) Cavitation C) Foaming oil in reservoir A) Cold oil is too viscous A) Cavitation B) Aeration A) Aeration A) Worn parts B) Too thin an oil A) Worn spools or orifices B) Electrohydraulic valve cavitation A) Sticking part suddenly overcomes the constricting force B) Sudden closing of directional valve	POSSIBLE REMEDY 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. A) Warm up the system with a pre-heater. Run system under no load until operating temperature is achieved. A) Find obstruction (restriction) in line and correct it. Clean suction filter. B) Find and repair suction leak. Check fluid level in reservoir. A) Fill reservoir if low on fluid. Tighten all connections. 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. 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. 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.