front end loader won't lift

[Donibnole]

My front end loader on works when fluid is cold. The bucket won't even raise
when the tractor reaches operating temp. What is wrong, weak pump, leaking past a seal e.t.c

 

[LD1]

My front end loader on works when fluid is cold. The bucket won't even raise
when the tractor reaches operating temp. What is wrong, weak pump, leaking past a seal e.t.c

It could be either of those or even a fauty PRV.

You really need to spend $10-$20 and get a hydraulic pressure guage. When the probem occurse, you can test the ports going out from the controls to the loader. If you are making at or near the rated pressure, the problem is beyong the valve. Like the hoses or cylinders. If you arent making the PSI there, it is either the pump or supply to the valve.