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

Quick reference troubleshooting guide.

Pump makes excessive noise
A) Air leaks in the suction side of pump

B) Aeration of fluid in reservoir

C) Plugged or restricted suction line, suction strainer or filter
A) Install a vacuum gauge in inlet on a naturally aspired reservoir. If indicates zero, air leakage may exist. Replace fitting and/or line. Replace pump shaft seal. Check fluid level. Check pump housing for cracks. Check torque of pump housing bolts.

B) Return lines terminate above fluid level. Check fluid level; too low causing excessive heat and foam. Check fluid for foam by drawing a sample from reservoir.

C) Check for proper suction line size. Check for proper filter or stainer size. Remove, clean or replace filter or strainer
Pump fails to deliver fluid
A) Low fluid level in reservoir

B) Pump intake restricted or plugged

C) Air leak in suction line and/or air lock
A) Check fluid level, fill to proper level

B) Check for proper suction line size. Check for proper filter or strainer size. Remove, clean or replace filter and/or strainer.

C) Repair leaks. Check pump housing drain port for improper positioning, allowing air to be trapped in housing. Bleed pump inlet.
Oil leakage around pump
A) Shaft seal worn

B) Suction or pressure

C) Pump housing bolts loose or improperly torqued
A) Remove and replace. Check shaft fro scratches and grooves. Replace if necessary.

B) Tighten or replace connections. Line connections loose or broken.

C) Disassemble and inspect seals for damage. Re-torque to specification. Follow manufacturers torquing procedure.
Pump does not develop pressure
A) Pump not delivering fluid

B) Vane(s) in vane pump sticking. Piston(s) in piston pump sticking

C) System relief valve unloading, or compensator malfunction
A) See corresponding troubleshooting chart above

B) Disassemble and inspect for burrs and/or varnishing. Replace and/or repair as necessary. Flush system thoroughly and refill with filtered fluid.

C) Check each for broken, worn or stuck parts. If stuck due to contamination, drain, flush and refill system.
Low or erratic pressure
A) Cold fluid

B) Wrong viscosity fluid

C) Aeration or cavitation
A) Operate machine to raise temperature of fluid to normal operating temperature. Check pressure again.

B) Drain and refill system with filtered recommended fluid.

C) See excessive noise troubleshooting chart.
Excessive pump wear
A) Abrasive dirt in hydraulic fluid

B) High water content fluid incompatibility

C) System pressure exceeding pump rating
A) Drain and flush system thoroughly. Replace filter elements.

B) Check manufacturers recommendation about the use of high water content fluid (HWCF) in the pump.

C) Check for possible relief malfunction. Check for other pressure regulator failures.
Pump parts inside housing broke
A) Seizure due to lack of fluid

B) Excessive system pressure above maximum pump rating

C) Excessive torquing of housing bolts
A) Check for cavitation or aeration. Check for too low or too high an oil level. Check viscosity of fluid.

B) Check pressure controls for possible malfunctions. Repair or replace as necessary.

C) Repair or replace parts as necessary. Reassemble following manufacturer's procedures.