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Fisher MM1 Pump slow to go down

Discussion in 'Truck & Equipment Repair' started by Ziob34, Jan 11, 2014.

  1. Ziob34

    Ziob34 Senior Member
    Messages: 182

    took apart our backup mm1 plow pump cleaned it all out and put new fisher blue in it as it had old fluid that had some water in it and would run bad in the cold. Now it works fine in the cold only thing is it goes down very slow. Anyone have this problem? it'll go up relatively fast but when you drop it it takes forever to get down it won't just slamn down like it used to. I did take off the valve block to clean could i have tightened the releif valves in to much? Or is it a bad up and down solenoid not releasing all the way to let the fluid out? Used to be able to hold the plow control down and push it down manually now can't barely moves if someone stands on it.

    Any tips would be great probably something simple everything else works fine angle left, angle right, and going up.
     
  2. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,924

    Adjust the quill. Small screw right on top of the valve body
     
  3. Ziob34

    Ziob34 Senior Member
    Messages: 182

    will give it a try maybe i over tightened it.
     
  4. Ziob34

    Ziob34 Senior Member
    Messages: 182

    Good Call had it to tight works fine now thanks for the help
     
  5. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,924

    Good deal....
     
  6. FreshGrounder1

    FreshGrounder1 Junior Member
    Messages: 26

    same for Fisher MM2?

    I have the same problem with one of my MM2s. Can you guys elaborate a bit on the location and issue with the quill? This plow came new on a used f250 purchased last year, and it has always been slow on drop, my older MM2 is fine and has a hell of a lot more hrs on it. Thanks
     
  7. kimber750

    kimber750 PlowSite Veteran
    Messages: 3,578

    Small flat head screw facing straight up next to reservoir. Quill is only used to adjust drop speed of the plow. Turn it out to drop faster, turn it in to reduce drop speed.
     
  8. unhcp

    unhcp PlowSite.com Addict
    Messages: 1,243

    watch your feet!:)
     
  9. FreshGrounder1

    FreshGrounder1 Junior Member
    Messages: 26

    Thanks guys. Looking forward to checking it out as soon as it gets above freezing to wash the plows and trucks and actually see what im doing!