Weak Hydro pump

[Hopper1]

I just bought a 2000,928D2, 1100hrs. It is weak on the right side, it seems to drive straight but turning forward or reverse is very weak. Is there any way to check oil pressure? Any ideas?

Update....Right pump is ok. Idler on R side was binding up, needed new brass bushings. Apparently it was not keeping pump drive belt tight enough. After changing the Hyd filter, now it seems to be on the left side, low power. I think it has air in the pump now. It was not there before. There is a allen plug on top od each pump. Is that to let air out of each motor? Help again.

 

[ingqman]

I have a 618 with the same problem, I took it all apart and found nothing wrong, I do have a leak somewhere but I cannot find it. The mower has 1200hrs on it, but I have only had it for three weeks now. I am going to take the pump into the local dealer tomorrow and ask to have it rebuilt.