672d grader. Weak hydraulics

[Tx33cowboy]

Got jd 672d grader. Had weak hydraulics and the hydraulics were overheated. Pulled the filter and it was full of glitter. Installed new hyd pump. New oil. Blew out all the lines. While the pump was out of machine. Started it up. Checked for leaks and oil level. Operated it and hydraulics seemed fast and responsive. Lasted a few minutes. And now I’m back to having weak/slow hydraulics unless I rev the engine really high. The oil gets warm but not hot. But for the amount of running I think it’s getting warm to fast.

Any help would be appreciated. Hydraulic Schematics and pressures.

 

[Steve Austin]

Did you loosen the bleed port on new pump and make sure case was full of oil no air before starting machine up?

 

[Tx33cowboy]

All air was out of system. Found that the system pressure valve had a bad o-ring

 

[Steve Austin]

Glad that was only problem and thanks for posting fix.