Another jerky hydraulics question :-/

[vc1911]

It's my first post so be gentle...

We have an m5400 probably a '94-'95. My older brother bought it new it's been great. A month ago the hydros became jumpy. About a year ago I replaced a few hydraulic lines on the loader to dryrot, but I didn't think it was very much fluid lost.

I've checked and topped off the fluid (which was almost full)
checked the macaroni vent
the inlet to the pump has a metal tube not a rubber hose-I can't find a fluid leak or a vacuum leak

The 3ph and loader are jumpy

I feel like its air in the lines not trash in the filter bc they still work and aren't at a complete stall. Is there a bleeder nut or a purge valve somewhere?
What am I missing?

 

[Diydave]

Have you replaced the filter?

 

[mickeyd]

Welcome to OTT VC. Nice tractor. There are a lot of M series tractor owners here, but since it wasn't doing it before, it shouldn't be the same problem as the newer smaller tractors are having with jumpy 3pt lifting.

 

[North Idaho Wolfman]

While there is no hose there is a set of O-rings that can leak.
Also if you haven't done so, replace both filters and fluid at the same time.

A bad set of filters will cause it to suck air.

 

[IronworkerFXR]

+ 1 on the filters and O rings

 

[vc1911]

Dave no sir.
Mickey thank you!

Wolfman humor me for second, so if the filters were stopped/clogged it could cause the system to pull air around the Orings?

Are these Orings something I should always change when the tractor gets serviced? I would like to do this myself bc the closest dealer is an hour away from me now.

Thank you guys so much!

 

[North Idaho Wolfman]

Yes plugged filters can cause it to suck air.
O-rings are good for many years, its just a good idea and cheap thing to try to fix your issue.