Ford 4000 hydraulic issue

[powerontheland]

I have a ford 4000 that as started to lift the linkage right to the top with the quadrant lever down. It had been working fine. If I feather the pull valve for the external service I can get the arms to drop. Any ideas what the issue may be please?

 

[forblue]

Sounds like unload valve stuck which means top cover off easy to do,do's the lift lever feel the same as normal, as it's unlikely but linkage pin may have dropped out if so lever will feel very loose, if you stop engine put lift lever down and get the arms down then not moving anything start eng and lift arms come up unload valve has stuck, happens mostly if hyd's not been used very often and or rear end oil has condensation in it,if you are unsure where the unload valve is get your cnh dealer to send a diagram via e-mail of the lift cylinder and components with part description................

 

[Mursal]

Oil to heavy?

 

[Mursal]

Oil to heavy?

 

[Flat 10]

Unlikely but has draft/position lever got knocked?

 

[powerontheland]

Unlikely but has draft/position lever got knocked?

No, tried that. It’s in for refurb, so I will whip the top cover off.

 

[REStracTORATION]

Just had a major in doing exactly the same thing
Slightly different I know
But it was the unloader valve jammed and the position valve too white oil and stood for a few years

 

[powerontheland]

Just had a major in doing exactly the same thing
Slightly different I know
But it was the unloader valve jammed and the position valve too white oil and stood for a few years

This is most likely my problem as she had sat for 10 years before i got her