How to Troubleshoot a Hydraulic Pump

Hydraulic pump technology is applied in a very wide array of situations and uses, from heavy industry machinery to products used around the average home. For instance, riding lawnmowers often use a hydraulic pump driven by the motor. If you notice a hydraulic pump that may not be functioning properly, try some troubleshooting steps.

Items Needed:

1. Check the hydraulic oil filter. It is usually found on the discharge, low-pressure end of the hydraulic system and is responsible for filtering the high-pressure fluid as it is passed from the hydraulic cylinder or motor. The oil filter should be clean and in good condition.


2. Check the suction screen metal filter. This metal screen should not be clogged or it will create pressure issues in the hydraulic pump.


3. Test the pressure relief bypass valve for proper operation. You can do this by attaching a pressure gauge to the pressure relief valve port. Remove the setscrew plug with an Allen wrench and insert the pressure gauge. Tighten it using an end wrench. Turn the hydraulic system on and check the reading on the pressure gauge. There should not be any fluid pressure registering.


4. Check the hydraulic fluid temperature using the tank thermometer. Excessively hot fluid will cause the pump seals to burn or scorch. It can also be an indicator that the pump seals are being bypassed. 


5. Examine all the bearings and pump seals. There should be no leaks present, no matter how slight, as this is an indicator of a mechanical problem with the hydraulic pump, namely a failing bearing. Though a pump can function for a long time with a leak, it will eventually fail completely and you will want to address the issue before this occurs.


6. Use an infrared thermometer to check various hydraulic system components. The primary consideration you want to check for is excessive heat while the hydraulic system is in operation.