Hydraulic Gear Pump Failure Analysis

Determine Cause of Failure

Prevent Repeat Failures

Some failures result from only one cause and the reason is often obvious. Other failures are a result of a combination of causes. You must be very careful to determine all of the causes and eliminate them to prevent repeat failure. Examine all of the components available and consider all other factors which may be have contributed to the cause. It is often very helpful to have some history of the machine. To completely analyze a hydraulic pump failure consider the following items:

Condition of each component
Type and condition of hydraulic oil and filters
Operating conditions and symptoms before failure
Conditions of other hydraulic system components
Severity of job application
Amount of service received from pump before failure
Previous failures and repairs in the hydraulic system

A knowledge of the pump service life is an essential part of pump servicing. Even if the pump provided a satisfactory period of service before failure, several precautions must be taken to insure that the new pump will provide a similar period of service. (see installation instructions)

If the machine's records indicate that pump life shortens with each replacement pump, you can be sure that these instructions were not followed. The troubleshooting information and the illustrations should help in diagnosing hydraulic pump failures.

For details on operation, service and repair of any part of the hydraulic system, refer the the appropriate service manual for the machine.