It is most likely the hydro pump seal. We have had that seal go out on a couple of different machines. The pump should be removed from the machine to put in the new seal. A mechanic with alot of experience may put it in, with it still in the machine. The seal can be damaged by just touching it in the wrong place. We have gotten the seal thru Massey and Case. They both use the Eaton pumps. Some times you have to let the machine run for a while in order to get that seal, to seal off properly.