What Happens When Hot Oil Meets a Cold Hydraulic Motor?

radial piston motor failureA recent client asked me to investigate and solve a recurring problem on a diving bell launch and recovery system. The system comprised a hydraulic power unit, a bell winch, an umbilical winch and a guide-wire winch.

To launch the bell, the guide-wire winch is used to lower a clump weight to the seabed. The guide wires prevent the bell … Read more

How NOT To Destroy a Hydraulic Pump During Start Up

pressurized hydraulic systems are dangerousOne of our members wrote me with this question:

“I was subcontracted to remove a 30 GPM, 4000 PSI rated hydraulic pump from one plastic injection press and install it into a similar hydraulic system.

The hydraulic pump and prime mover are both beside and below the bottom of the reservoir; a “flooded inlet” design. AND, except for the ball Read more

How To Prevent ‘Dieseling’ In Hydraulic Cylinders

hydraulic cylinder failureI was recently engaged by a client to conduct failure analysis on a large (and expensive) hydraulic cylinder off an excavator. This hydraulic cylinder had been changed-out due to leaking rod seals after achieving only half of its expected service life.

Inspection revealed that apart from the rod seals, which had failed as a result of ‘dieseling’, the other parts … Read more