Tandem Piston Pumps, Shaft Seals and Case Drain Lines

IM000260A 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

Hydraulic System Cavitation and Many of Its Causes

photo credit eaton vickersCavitation 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

How a Little Detail Caused a Huge Hydraulics Problem

Hydraulic Solenoid Valve (Bosch Rexroth)A Hydraulics Pro Club member from South Africa sent me this story about a hydraulic system overhaul that turned into a troubleshooting nightmare:

“My company was contracted to overhaul the hydraulic system in a beverage pasteurizing unit. The system was extremely simple but the pasteurizer, after 20 years of trouble free service, was going to be critical in the launch Read more