7060 Hydraulics - or lack there of-

I checked over the black belly 7060 this morning, then went to the field with the 20' bush hog to do some stalk-chopping, worked till dinner time, folded it up and went home, let the wings back down and set the implement down.  Came back after lunch, started it up, lifted ti up, and headed towards the field.  When I went to fold the wings up when I came to a narrow bridge, the wings wouldnt fold all the way up and the steering stopped working.  I shut it down, checked the oil and it was low in the rear sight glass.  Filled it back up, folded the bush hog up and went to the field.  I made a round or two, stopped, checked the oil level and it was still in the top sight glass.  Got back in the tractor, drove about 100 yards, steering started getting jerky, then the PTO stopped.  Checked the oil again, just fine. Tried to lift the bush hog but the levers act like they dont even try, no steering.  It drives and shifts (power director works too) just fine.  I didnt have any idiot lights going off (but this is a used beat up tractor and I cant guarantee they work), didnt hear any noises/feel anything before.  What should I look for/ start replacing? Is it something I can fix, or do I need someone more professional?  Thanks in advance

How much oil did you have to add??? when was the last time the left hand hyd filter was changed???

Had to add a lot more oil than I would like to admit (10 gallon) (after I parked it, I saw a drip and followed it, had a leaky hose on the deck of the bush hog.  I was going over terraces so I was doing a lot of raising and lowering. All the corn leaves and chaff blown up there just absorbed it, so I didnt notice. Probably a pretty costly mistake) No idea on when the filters had been changed last.  Oil looked clean when I got it (about 75 hours of run time or so ago).  I had to tear down the engine because of a bad sleeve, and the rest of the motor looked like a pretty fresh overhaul, so I assumed it had regular maintenance.  

IF it's not the filter, we had the return spring break in the variable flow pump (front), the PTO, quit, the power steering was weak at best, no hydro, nothing.  What happens is the piston wable plate centers or over centers and then the pump either has little to no flow or actually reverses flow.  You probably aren't into it too bad, so long as it has some oil in there.  But check your presssures as the service manual says, then you can open the pump up if you need, as of last year all the parts were still available, I think we had it back in the field for under $45.00, not sure, but it wasn't too bad.  Just be real careful when taking the pump apart, it has quite a few pieces in there that need to go back were they came from for wear reasons.

Edited by Orange Blood - 04 Oct 2011 at 9:36pm