Hydraulic question.

[Truckie]

Hydraulic question.

At work we got a machine to be specific it is our problem child, it is a FUCHS 350 magnet crane.
It has more hydraulic problems than you can shake a stick at.
Fix one leak and get to more the next day and so on.
Since we have had this machine in 3 rears we have replaced with out a doubt 50 hoses and or fittings and a few spool valves.
So the questions I have is. One of main boom cylinders leak and both will bleed down really bad when the machine is cold. Once it is hot it will bleed off but real slow.
Will this symptom cause or let air in to the hydraulic system? And will it cause the machine to make to much pump pressure because air is getting in the system and not letting the pressure relief valves work properly? Causing us to have so many leaky hoses and fittings?
It is so bad this machine can use up to 30 gallons of hydraulic oil a week.

[mascas]

A leaking cylinder should not let air in at all.If your pump runs low on oil it will cavitate and fill the system with air,but your machine will not work anyway.If your cylinders are leaking down it could be the cylinders or most likely your holding valve bleeding by. You need to get a set of gauges and check all your pressure ports. This will narrow down your problem

[Johnsoils]

Could be a cavitation issue creating a "water hammer" effect on the hose and spool valves shortning their life. Has this machine ever had a pump or major system component failure on the hydraulic system?

[Dualie]

sounds like your over heating your fluid to me. No advice on the cure but your in the perfect storm to overheat your hyd fluid.