Grasshopper hydro problem

Discussion in 'Mechanic and Repair' started by Goinbigger, Jun 5, 2012.

  1. Goinbigger

    Goinbigger LawnSite Member
    Posts: 8

    I just picked up a 1988 Grasshopper 1822K. The gentleman I got it from said he had previously sold it, got it back when the guy tried driving it with the parking brake on and snapped the input shaft for the left hydro. He replaced the input shaft and then it started getting weak. He didn't want to deal with it anymore and then I bought it. Come to find out it works great in reverse. Just has no power going forward.

    I looked all over the intraweb for possible causes. (This is an Eaton Model 7) Main two being a stuck check valve and a bad cam ring in the pump side.
    I just finished tearing it apart (yes I made sure the balls stayed in place).
    Now I can't find anything that jumps out and says I'm the problem.
    Two things I noticed while tearing it apart were that the input shaft rocks in it's bore, like the bearing is worn out. And there was a very small part missing from inside the case. Which is the "button" Page 15 fig. 38 here> http://www.scribd.com/doc/50699099/WheelHorse-Eaton-model-7-service-manual

    It seems like that button wouldn't really have much of an affect on the operation of the pump though. Maybe I'm wrong. The balls and races all looked good, the check balls move freely in their bores (I have no idea if they seal properly though). I guess my next step would be to order new seals, that button, input shaft bearing and some new check valves and replace them to see if it fixes it.

    Anyone else have any other ideas as to what it might be?
     
  2. pepsicolla

    pepsicolla LawnSite Member
    from ny
    Posts: 16

    Im having a very similar problem. It sounds like the pintle or the shafts on your motor rotor are worn and letting letting fluid bypass the balls. I know the motor rotor and the pump rotor have what look like brass sleeve bearings that wear in them so I have been looking for replacement sleeves but no luck yet. Let me know if you come up with something. Rich
     
  3. Goinbigger

    Goinbigger LawnSite Member
    Posts: 8

    Are you talking about the races? The grooved part the balls ride in? If that was the problem it would allow fluid to bypass both ways, not just one. It works fine in reverse. The pintle itself seems to just divert fluid to either check valve. About the only way you could wear that out is if there was a groove in between the milled slots, but again, it would affect both sides if that were the case. It also allows fluid to be drawn from the reservoir from the opposite check valve.
    If you are referring to the races, for the pump side I guess you can just order the cam and it comes with a race installed already. The motor side you would need to pull the old one and press the new one in.
    From what I can find Eaton is about the only place you can get parts for them and you will probably have to call them directly in order to get them. I haven't found a single source on the net that has parts for them.

    I'm still not sure what the problem with mine is. The only thing I can figure is that the forward check valve is not seating properly, but I have no way to really know that. They move around freely, but I really don't want to just assume that is what the problem is, I didn't see anything come out when I flushed them. If I did I would just put it back together and give it a shot. But without seeing anything I don't want to just put it back together without seeing any problems.
     
  4. pepsicolla

    pepsicolla LawnSite Member
    from ny
    Posts: 16

    Sorry I didnt read your post very well it seems. I didnt know it worked in reverse. Have you taken the check valve bodies and balls out. Maybe one of the balls is not seating properly do to a obstruction or wear on the ball or body? My problem is there is wear scoring on the pinlte shafts and the brass bearing inside both motor rotor and pump rotor. Im hoping I can at least order both the brass sleeve bearings in the pump and rotor. As for the pintle damage its not as bad so Im hoping it wont be a problem. Im calling eaton today Ill let you know if they are still selling parts for these pumps but I doubt it.
     
  5. pepsicolla

    pepsicolla LawnSite Member
    from ny
    Posts: 16

    So I called Eaton's main office in Minnesota and they dont sell parts apparently. They referred me to my local eaton service center and they said the pumps are considered "Throw away pumps" so parts are not available. But they were happy to give me a quote on a new one $950. This sucks.
     
  6. Mowingman

    Mowingman LawnSite Platinum Member
    from Texas
    Posts: 4,656

    Eaton quit supporting those really old hydro units just a few yeara ago. Until then, you could get parts for them.
    You might give the Grasshopper factory a call and see if they know someone who has a stash of those older parts.
    Grasshopper SOMETIMES has rebuilt Gemini hydro units available for sale. The supply is very limited, and they often have none available. But, you might get lucky. If available, the price is close to what you were quoted from Eaton.
     
  7. Goinbigger

    Goinbigger LawnSite Member
    Posts: 8

    What is strange too is that you can get them new on ebay for $625 Just search for eaton hydrostatic and they pop up.

    That is quite a price difference.
     
  8. Goinbigger

    Goinbigger LawnSite Member
    Posts: 8

  9. pepsicolla

    pepsicolla LawnSite Member
    from ny
    Posts: 16

    Ya I seen that. Problem is I have $500 in the mower and would hate to spend more than its value on just one pump. Im thinking about having the brass bearing sleeves milled or find a place that can cnc them. IDK I should just buy a different mower lol
     
  10. Goinbigger

    Goinbigger LawnSite Member
    Posts: 8

    Well just for my curiosity I put the left hydro back together and stuck it in the mower. It works great! Now if I could get the right one to work again. I think I have air stuck in it. I've tried bleeding it over and over, drained it, filled it back up again, bled it over and over again. Still won't work. I noticed the reservoir had a ton of crud in it when I had the other hydro out, so I pulled the res and cleaned it out. I wonder if that crud clogged one of the check valves on the left hydro and is now clogging the right one?
     

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