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fisher problem

Discussion in 'Fisher Engineering Discussion' started by HOMERPLOWKING, Feb 20, 2013.


    HOMERPLOWKING Junior Member
    from cny
    Messages: 2

    I have a fisher mm2 on a 1999 Chevy 2500. It works fine except when there is pressure on right side of blade it will push back. I was just wondering what you guys thought the problem could be?. I was thinking leaking by internally of the ram. Thanks for any help.
  2. jb1390

    jb1390 Senior Member
    Messages: 710

    There is a relief valve that prevents overpressure, and is there to protect your plow.

    It would not be the ram, unless you have fluid pouring out of the seals and onto the ground. The rams are single action, meaning any fluid that passes the seals leaks out of the system entirely. A double acting cylinder can leak in the manner you describe, but you don't have any of those on your setup.

    Are you trying to push wet, heavy, or icy piles when this happens?
  3. kimber750

    kimber750 PlowSite Veteran
    Messages: 4,677

    Would suggest checking crossover valves.


    HOMERPLOWKING Junior Member
    from cny
    Messages: 2

    Thanks guys. Yes Jb anytime there is extra pressure on right side of blade it does this. Not really anything extra heavy. It did not do this before. I will look into crossover valve. But I may wait till after season. I can get buy with it now. I don't want to open a can of worms. Thanks again for the input.
  5. PeteB4

    PeteB4 Member
    from Maine
    Messages: 56

    Mine's doing it both sides! Happened last storm (Sunday) and another big one coming.!
    Would both left and right also be crossover valves?
  6. jb1390

    jb1390 Senior Member
    Messages: 710

    It's normal. Designed to do that so you don't break expensive parts. On many plows it is adjustable, but I'd rather have that valve give and protect my blade than up the pressure and bend something.