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Set-screw on Fisher Pump, Increase speed?

Discussion in 'Fisher Engineering Discussion' started by MRBachand, Jan 23, 2009.

  1. MRBachand

    MRBachand Senior Member
    Messages: 198

    When cleaning out my resevoir to diagnose probable ice in my system, I noticed this screw on the hydrolic pump part inside the resevoir.

    What would happen if I adjusted this? Would it speed up the plow?

    The 'set screw' is the shorter one, the longer one is the one that goes into the starter motor on the MM1 plows.

    This is my 'backup' one. The one I'm running in my plow has none of that rust on it.

    Hydraulic PUmp 004.jpg

    Hydraulic PUmp 003.jpg
  2. Crash935

    Crash935 2000 Club Member
    Messages: 2,377

    No, it wont make it run faster. That is the pump relief setting. You can make adjustments but you can go to far and damage the pump. Its best to check the pump pressure with a gauge before you start turning things.
  3. Lowell_Ma_Snow

    Lowell_Ma_Snow Member
    Messages: 60

    I have to ask but is Elmo helping you out? I say tywrap him to the plow between the lights.:dizzy:
  4. Crash935

    Crash935 2000 Club Member
    Messages: 2,377

    I didnt even notice him in the pics, thats funny!
  5. MRBachand

    MRBachand Senior Member
    Messages: 198

    My daughter would kill me!!! LOL, I figured someone would get a kick outta that.

    Ok, so thats a reliefe screw. I will not touch it. Thanks for your help.
  6. Crash935

    Crash935 2000 Club Member
    Messages: 2,377

    Like i said, it wont make it go faster but if your noticing slower or a struggling lift it might be a good idea to put a pressure gauge to the system to see where its set at. If its to low then you can so some adjusting on the relief.