Bad Wheel motor, pump, or air in system?

Discussion in 'Mechanic and Repair' started by lsylvain, May 19, 2009.

  1. lsylvain

    lsylvain LawnSite Senior Member
    Posts: 777

    I have an exmark 60" hydro. pre 1995 model I just got. The hydos were working fine when I bought it and drove it around. I bought it, put it on the trailer and when I got home the left tire had no drive forward or reverse. It sat for a year before I bought it and apeared to have new hoses so I thought maybe had air in the system. How can I tell what the culprit is without spending $1000 on a $500 machine?

    thanks,
     
  2. puppypaws

    puppypaws LawnSite Fanatic
    Posts: 8,945

    Jack it up to get the rear wheels off the ground, (make sure it is very stable) sit on the mower and activate the hydraulics by pushing the steering handles forward about 1/3 of wide open. Hold them in this position while looking at your rear wheels to see if they are both turning. This will purge any air from the system, I hope this is your problem but seriously doubt it. Make sure the hydraulic by-pass valves are completely closed, the ones you open if you need to pull the mower in free wheel.
     
  3. lsylvain

    lsylvain LawnSite Senior Member
    Posts: 777

    Yeah I already tried that. I'm getting some movement in the left but not much. If I turn the wheel by hand I can hear what sounds like fluid getting pushed around, but it is very easy to turn the wheel. Not as easy as freewheel but pretty close.

    There has to be a way i can test the pump and wheel motor seperatly?
     
  4. KensLawnCare

    KensLawnCare LawnSite Member
    Posts: 104

    make sure the hydro there is a screw to turn on the pumps so it will be nuetral make sure its turned tight
     
  5. KensLawnCare

    KensLawnCare LawnSite Member
    Posts: 104

    did you check fluid levels maybe needs changed
     
  6. lsylvain

    lsylvain LawnSite Senior Member
    Posts: 777

    nope not the problem. All the routine checks have been done. How do I find out if pump or wheel motor is the issue?
     
  7. puppypaws

    puppypaws LawnSite Fanatic
    Posts: 8,945

    Are you able to turn the other wheel by hand?

    Remove the wheel, the wheel motor has two ports where hoses hook up now. Remove the ports and plug your flow meter in, if pump test OK four bolts and remove wheel motor.

    If you are not experienced at this; you need to pay service person. If a pump or wheel motor has gone bad, the system is contaminated more than likely.
     
  8. lsylvain

    lsylvain LawnSite Senior Member
    Posts: 777

    What if I flip the hoses so that the right pump goes to the left wheel motor. If the wheel still doesn't run then I know it is the wheel motor, and if it does I know it is the pump.

    Also is there a fail proof way to bleed the system? I'm nearly certain there is a big air pocket in the top of the left hoses. They are the highest point in the system and I swear I can hear it "sputter" when I turn the wheel by hand. I've bled it several times and each time the wheel will turn slowly for maybe 5 rotations and stop and I get a lot of bubbles in the tank.
     
  9. puppypaws

    puppypaws LawnSite Fanatic
    Posts: 8,945

    This is straight out of the Exmark operators manual. I have seen this before where people did not run the mower long enough to purge all the air. These are the exact instructions, try this before anything else.

    QUOTE:

    f) Raise the rear of machine up and support with jack stands (or equivalent
    support) just high enough to allow drive wheels to turn freely.
    g) Start engine and move throttle control ahead to full throttle position. Move
    the speed control levers to the full speed and run for several minutes. Shut
    down machine and recheck oil level.
     
  10. Allens LawnCare

    Allens LawnCare LawnSite Senior Member
    Posts: 926

    I've been told that if there is air in the system, you'll be pushing Hydro fluid out of the reservoir...the tees in the hydro system go bad or become loose, you would think a leak or crack would leak out of the system but it draws air in which forces the hydro fluid out!
     

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