L48 HST Issues

[D100jj4]

I bought an L48 tractor last year.
I can’t run unit for long periods, once it gets up to operating temp tractor doesn’t have enough power to move. . I have to let it sit and cool off then it will move. So I changed hystat oil and filter, didn’t change anything. Oil doesn’t get hot.
I checked charge pressure and found 100 psi at high idle.
I inspected charge relief valve. I shimmed it up and was able to achieve 220 psi but that’s as high as I could get it to go. Spec is around 370.
I believe I might have an internal leak.
Has anyone ran into this or have any thoughts as to where I should look next.
Thank you!!!

 

[North Idaho Wolfman]

Have you looked at the Mecanical clutch at all?
Low input power to the HST unit can cause all the issues you are describing.

 

[D100jj4]

I checked the pedal adjustment.
But haven***8217;t checked the clutch.
How can I check to see if its slipping.
Can I check speed of pto shaft and see if it slows down some after it gets to operating temp?

 

[North Idaho Wolfman]

Yep that's exactly what you need to do, put a PTO powered implement on it and run the tractor till weak, then run the PTO and see if you have speed and power to it.