Hey all, this one has me a bit stumped. Customers machine, 6MF0-200 s/n. Just wondering if anyone has had issues bleeding air out of the pilot system. A few hundred hours ago customer had a RH joystick pilot hose replaced and routed incorrectly. I went out, corrected the hose, bled pilot system by the book, loosening the pilot lines on the main control valve with an operator in the cab (early cntrl valve without the bleed screws), but still have a fairly loud cavitation sound coming from the RH joystick when commanding anything.. About the same time, it developed an intermittent no tracking issue once the hydraulics warm up. While it's faulting.... getting good pilot signal from the steering/directional pilot valve but getting no pressure down at the track brakes to release them. Only thing in between the two is the swivel and the track brake valve. So I played with the shims in the track brake valve, no fix. Pulled the track brake valve, found nothing out of the ordinary, reassembled and put back in. Pilot pump replaced recently but before these issues started. If an o-ring was pinched here letting air in I'd expect to see a cold leak here too I would imagine. So I'm thinking I could just be chasing an air in hydraulics issue from when the hoses were installed incorrectly. Question... are these things just hard to bleed or are there some tricks I don't know about?
Anyone have any thoughts?
I've never had to remove air from a pilot system. I'd start by verifying proper hose routing at the pilot control and the other end of any removed hoses. Not familiar with a 245 but, have you confirmed proper pilot operating pressure? A "new" pump means nothing to me these days...it needs the pressure tested. Could any of the pilot port fittings have a small orifice and been transposed?
That's an excellent thought. I swapped two hoses at the joystick control valve to restore the correct functions... I later found that the hose (originally) routed incorrectly was external to the cab... so I think I'll have another good look over all the pilot hoses next time I'm out there. Pilot pressure I found was 300psi... spec says 335 +/- 25. It's slightly under so I'll bump that up a bit and report back also.