Sparky6619

I know this is a old post but maybe this will help others that read it. Unless the seal leading to atmosphere is leaking then the inner piston seal is fine. The problem will be with a pump or ball or a weak spring or a setting. The piston will rise even with no piston to cylinders seal. It’s called displacement. Hydraulic fluid Go into cylinder and pushes the rod out, it does this even without a seal to bore. The seal t atmosphere fails then cylinder losses it’s oil and will retract under weight. OR if the valve keeping the oil in the cylinder fails. its not impossible to understand it’s just difficult too.