Troubleshooting
If for any reason the pump does not run properly, look for one of the following causes,
If the pump appears to be short stroking and running too fast without pumping properly, it usually indicates that the pilot valve assembly is not working as it should be. (See also Hydraulic Pump Seal Replacement refer "The hydraulic piston" and "Repairing the pilot valve assembly" for correction procedure).
Loss of pressure may be caused by one of two reasons, the hydraulic check valves have developed a leak or the hydraulic fluid is bleeding past the packing in the hydraulic Cylinder. (See also Hydraulic Pump Seal Replacement to replace the packing in the hydraulic cylinder", "The hydraulic piston" and "Repairing or replacing the hydraulic check valves for the correction procedure).
Should the pump run erratically and in a jerky manner after a period of time, it is usually an indication of seizing in the hydraulic piston & cylinder assembly. (See also Hydraulic Pump Seal Replacement refer "To disassemble the air motor" and "To replace the packing in the hydraulic cylinder for disassembly instructions). If the hydraulic piston and cylinder have not been damaged, a thorough cleaning will normally place the pump in operation again.
To ensure hydraulic fluid flow is optimised, ensure sufficient air volume is supplied to the pump. Hooking the pump up to a smaller pipe size than the “AIR IN” port on the pump will not allow it to run at its full rated capacity. Long runs of relatively small pipe supplying air to the pump will have the same effect.
If an excessive amount of oil or water is pouring through the pump air exhaust, check for and correct;
Lubricating unit in the air supply is delivering too much oil. Adjust to about one drop of oil for every 20 strokes of the pump.
The hydraulic fluid being pumped (oil or water) may be leaking past the packing in the hydraulic cylinder into the air motor. (See also Hydraulic Pump Seal Replacement refer "To replace the packing in the hydraulic cylinder" for correction procedure).