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help fisher mm1 wont angle

Discussion in 'Truck & Equipment Repair' started by bob12, Dec 3, 2007.

  1. bob12

    bob12 Junior Member
    from maine
    Messages: 1

    help i have a fisher mm1 on my 99 ford. it was working fine last year and i started it up today, it goes up and down but when i angle, it goes up.
  2. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    The S3 valve is stuck open.. you can pull it out and try freeing it up with some brake cleaner while pushing in on the end of the spool with a small screwdriver to see if it will free up..but usually the small spool return spring inside the valve is broken, which won't allow the spool to return to it's neutral closed position so many time's they just need to be replaced.

    Here's a pic showing which valve is the S3.. if you remove the plastic cover off the back of the pump you will see the three valve shown here..

    To remove the valve, first remove the nut on the end and slide the coil off the valve, and then unscrew the valve for the manifold..

    Valve Block.JPG