Re: HF hydraulic press problem

[jeff-register]

Louis,
These guys have it right except O-ring density problems. As the piston travels in the bore the o ring is to stay in place. With the wrong density the o-ring will roll in the bore dumping fluid as it travels & sucking in air.
Another problem I have seen is the flex hoses start to fail & tiny pieces of the inside of the hose get into the valve body & make things not function as the tiny chunks hang up everything. Feels like fine sandy grit in the oil. Check it before you run not true & damage the cylinder or piston. See if you are sucking oil from a leaking fitting too. Take it apart, A guy like you will find it easy.
Jeff