Case ih 385 loader won't lift

[bigred 01]

I have a 1987 Case ih 385 with a 594 allied loader.
after the tractor warms up I lose my lift on the loader I still have down pressure, and I can dump the bucket.
The three point arms also works, the steering works but makes noise.

 

[J_J]

Install a gage and check the pressure.

Does you valve relief ever activate?

Can you raise the front wheels off the ground?

Is the spring centering on the valve working correctly. Sometimes the nut backs off the spring.

 

[bigred 01]

yes I can raise the front wheels off the ground with both the arms and the bucket.

the joystick for the loader just seems to go dead in the lift position after the tractor warms up.

the tractor started having the loader problem after I had run brushog on 3 point for 3 or 4 hours.

when the tractor is cold the loader works fine, it raises fast and has plenty of lift power.

 

[J_J]

You might try a different hyd fluid.

 

[cyrush]

Sounds like a tired pump !!!
You need to get the unit tested on a flow rather to test pump efficiency. Oil and filter can also affect performance so check theses first!!