A repairer rebuilt a hydraulic piston pump. A week later it came back like a boomerang, the subject of a warranty claim. Upon tear down the piston retaining plate was found to be broken–see inset pic. Fearing the aftermarket parts they used were not up to scratch, the repair shop quietly accepted warranty and rebuilt the pump for a second … Read more

In chapter 13 of The Hydraulic Maintenance Handbook I discuss in detail the elimination of problems by engineering them out. An obvious example of this strategy is, if a hydraulic system has tapered thread adapters, their replacement with a more reliable type of connector eliminates the possibility of recurring leaks. Job done. And if an oil to water heat exchanger … Read more

Cavitation is the term used to describe the formation of gas cavities within a liquid. In a hydraulic system, this is normally taken to mean formation of vapor bubbles within the oil. But it can also mean dissolved air coming out of solution in the oil.

Cavitation erosion occurs when gas cavities in the oil collapse (implode) under pressure, in … Read more