muddstopper
Veteran Member
I have one of the first ventrac tractors made. Hydrostatic, closed system. Lately, it has started puking oil back out the tank vent tube while running and will keep dumping the oil until the hydraulic level gets so low it wont operate. I havent started to trouble shoot to see whats causeing this yet and thought that I would ask where to start looking. Recently, I blew a hydraulic line and replaced it with a new one and that is about when this probelm started. At first I thought that maybe I had just overfilled with oil and that was what was causing it to overflow when it got hot. The next time I went to use the machine, the oil level was below the sight glass so I refilled and it would just pump it back out the overflow when running. I thought maybe air in system, but? I can fill the tank with engine off and cold and watch the oil level bubble down in the tank so I know the oil is going internal somewhere which should bleed the air from the system. I have tried filling with oil while the engine is running, it will take oil and then blow it back out the tank. To me it acts if air is trapped in the system, but I havent figured out a way to bleed it. I am open to any opinions or suggestions as to what may be causeing my problems, and if it just air locked, how best to correct it.