Parker P1 Series - Troubleshooting

Parker Hannin Corporation
Hydraulic Pump and
Power Systems Division
Marysville, Ohio USA
Bulletin HY28-2665-02/SVC/EN
Medium Pressure Axial Piston Pumps
P1/PD Maintenance
6
Trouble Shooting
Component problems and circuit problems are often interrelated. An improper circuit may operate with apparent success but
will cause failure of a particular component within it. The component failure can be the effect, not the cause of the problem.
This general guide is offered to help in locating and eliminating the cause of problems by studying their effects.
Effect of Trouble Possible Cause Fault Which Needs Remedy
noisy pump
air in uid
leak in inlet line
low uid level
turbulent uid
return lines above uid level
gas leak from accumulator
excessive pressure drop in the inlet line from a pressurized reservoir
inlet line strainer acting as air trap
cavitation in
rotating group
uid too cold
uid too viscous
uid too heavy
shaft speed to high
inlet line too small
inlet strainer too small
inlet strainer too dirty
operating altitude too high
inlet pressure too low
misaligned shaft
faulty installation
distortion in mounting
axial interference
faulty coupling
excessive overhung loads
mechanical fault in pump
piston and shoe looseness or failure
bearing failure
incorrect port plate rotation
eroded or worn parts in the displacement control
erosion on barrel ports
and port plate
air in uid see noisy pump above
cavitation see noisy pump above
pressure shocks
cogging load mechanical considerations
worn relief valve needed repairs
worn compensator replace
slow response in check
valves
replace or relocate
excessive decompres-
sion energy rates
improve decompression control
barrel blow-off rotating group worn, excessive case pressure
compensator instabil-
ity
excessive line
capacitance (line volume,
line stretch, acumulator
effects)
reduce line size or lengths
eliminate hose