hydraulic repair

[rschadel]

I picked up a bobcat453 which had sat for about 5 years. It started right up after a fresh battery and minor things. the hydraulics all work except the tilt cylinder stays extended. it will return fully but extends even when pedal is mid position. it also leaks fluid from the drain hose. I am thinking the spring in the spring centered spool is bad, but don't see why that would cause a leak. I found no apparent reason for an external leak so I think it is an internal drain. any thoughts on this issue? Thanks.

 

[Tazza]

It's possbible the centering spring in the control block is bad making the ram extend. How long have you been running the machine for? it is possible it's air too, slowly bleeding out. Even bad piston seals or a loose nut on the ram allowing fluid to by-pass and le the rod extend with the weight of the bucket on it.
What drain hose are you talking about? not sure i know of one that is open to the air.