I am a professional serviceman of hydraulic pump. About several decades was devoted in maintaining pump. Several years ago, I have a dream, that one day I would own a hydraulic pump test bench. Because using in industry, you must be sure that the pump maintained was all right with evidences. The pump is not allowed debug after installation. If you install while it does not work well, it would lead tens of millions of losses for just one hour. If there was no test bench, the company would not have you repairing the pump even if you could maintain well.

     Pump in a hydraulic system was like the heart of a person that was the most important of a hydraulic system. If there was not a test bench, no mater how professional you are, you could not transfer to the standard.

     For example, the pump of excavator is double plunger pump. What should you maintain? It does not recover the pressure and flow, it should keep the power curve same. If it does not, a pump would do more while another would do less. And it would cut the lifetime of the pump that does more work. Therefore, it would affect the power of motor (lower working speed).