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Fisher engine driven snow plow problem.

Discussion in 'Fisher Engineering Discussion' started by charlierock, Oct 11, 2010.

  1. charlierock

    charlierock Junior Member
    Messages: 12

    When the control is in the neutral position and I rev the engine my plow raises anyone know why
     
  2. plowatnight

    plowatnight Senior Member
    from Mn
    Messages: 305

    If the vakve is manual, my guess is the rod is slightly out of adjustment. The only other thing that could be wrong is wear or failure within the valve itself. To determin this, see if by either by compensating the lever of adjusting the valve/linkage position you can get it to stop doing this. If it's electric over hydraulic, i'm thinking yo may have a weak cartridge, but I'm just guessing.
     
  3. charlierock

    charlierock Junior Member
    Messages: 12

    I pulled out the valves and they all look fine from what I can tell how can you tell when they are bad
     
  4. Tracy89

    Tracy89 Senior Member
    from Maine
    Messages: 167

    Mine has had this same problem before. Im not sure exactly without looking at it first hand but on the valve body there are nuts that hold the cable to the valve body. If you try and adjust the two nuts one way or the other it SHOULD be fine.
     
  5. charlierock

    charlierock Junior Member
    Messages: 12

    I dont have cables just wires and it looks like some kind of electrical control unit
     
  6. Tracy89

    Tracy89 Senior Member
    from Maine
    Messages: 167

    my bad...i was at the understanding that it was hydraulic driven not electrical....
     
  7. charlierock

    charlierock Junior Member
    Messages: 12

    so its safe to say its in the valve?
     
  8. plowatnight

    plowatnight Senior Member
    from Mn
    Messages: 305

    it's definitely a possibility. The cartrige may be weak or there may be a seal leaking. This should be a learning experience. Not too sure on this end, not familiar with the valve body.
     
  9. charlierock

    charlierock Junior Member
    Messages: 12

    where would i look for a leaking seal? I s it on the valve body
     
  10. plowatnight

    plowatnight Senior Member
    from Mn
    Messages: 305

    Are you able to identify which part of the assembly controls the lowering of the plow? If so, is it possible to 1) determin at what times the coil is energized? probably when called for lowering. are you able to remove the coil and valve cartridge? Be very careful small parts like to run and hide. Next I'd determin if any of the other cartridges are the same size, (right and left preferably) and if so, I'd swap them, carefully, make sure all if the parts are back together before you try to operate the plow. If you can do this and it fixes the problem, it would be safe to say the cartridge is the issue. If not the problem is deeper in the assembly like a crack or casting or stress flow in the porting of the valve body. If you can't swap a cartridge, you either need to buy a new one to troubleshoot this or take it to a servicing outlet. remember, my experience with fixing my own stuff is that sometimes I spend as much hanging parts as I would have if I'd just had a Pro look at it as they are often familiar with themost common failures.
     
  11. charlierock

    charlierock Junior Member
    Messages: 12

    Update: I replaced the "a" valve and still the same problem I then tore the valve body apart there are no seals in it except for three O rings. I am going to try replacing the b valve next. From my understanding the a valve controls the lowering and the b valve the raising and angle
     
  12. plowatnight

    plowatnight Senior Member
    from Mn
    Messages: 305

    you're learning
     
  13. charlierock

    charlierock Junior Member
    Messages: 12

    Tell me about it I am definitely learning I also have every plow shop in the city stumped. I need to get it fixed by first snow I have some accounts to take care of
     
  14. plowatnight

    plowatnight Senior Member
    from Mn
    Messages: 305

    Is there a possibility that the system is "leaking" energy to the coil that raises the plow up ? If you have a DVM you might use that for troubleshooting the circuits instead of a common testlight. This thing might be sensitive enough to act up if the current isn't at spec.
     
  15. charlierock

    charlierock Junior Member
    Messages: 12

    Good idea I have a true Rms dvm which will measure minut amts of current I will try that too I just purchased a b valve from eBay so I'll be changing that soon I took the truck to a major repair shop today and the guy said he never saw a setup like that before lol seems to be what everyone is telling me
     
  16. plowatnight

    plowatnight Senior Member
    from Mn
    Messages: 305

    I wonder if somebody took a manual valve setup and replaced it with their own 12 volt (I'm assuming it'd 12 volt. better check the valve body) I've often thought of doing this myself because I have the deal where you run the rods through the firewall. My old '84 chev I have the 6 hoses running right through the floor, It's ugly as hell but so simple with no failure rate