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MM2 creeping down..... (again)

Discussion in 'Fisher Engineering Discussion' started by grec-o-face, Oct 3, 2011.

  1. grec-o-face

    grec-o-face Senior Member
    Messages: 485

    Last season I had a case of the droops.... The blade would slowly drop on it's own. I fixed it with a fresh S1 Valve. I was good for the rest of the year.

    Just hooked my blade to move it out of storage and into my garage for pre-season work.... guess what, on my trip home the blade was creeping down again... every few miles I'd tap the fishstick to raise the blade.

    Is it common to go through valves this fast? What's the deal here?

    NOTE: I stored the blade all summer without moving it once. The triangle WAS NOT all the way down. The lift piston was UP about 3 or 4 inches. When I plugged in and went to "float", I had to physically push the triangle down fully. (because my spring-cable adjustment)
    But, what I'm saying here is that all summer the valve held without creeping. Why would it creep on me now?
     
  2. RepoMan207

    RepoMan207 PlowSite Fanatic
    from Maine
    Messages: 5,031

    The Lift Arm didn't creep down because it didn't have enough weight on it to do so. The fact that it doesn't fully retract on it's own tells me your packing nut might be too tight. Do you have a retration spring connected to it?

    It is NOT common to go through a valve that quick. Did you buy a new coil at the same time, or re use the old one?

    Another test that you can try is, put your plow up with the truck running, disconnect the controller from the control harness, does it creep down? Make sure to give it some time, drive it around.
     
  3. grec-o-face

    grec-o-face Senior Member
    Messages: 485


    I remember you telling me to disconnect the controller last season when I went through this. I also have a spare fishstick I can try afterwards.
     
  4. RepoMan207

    RepoMan207 PlowSite Fanatic
    from Maine
    Messages: 5,031

    If it's creeping down with the controller disconnected, it eliminates it as a possibility.

    Do you change your fluid often enough? First pull the valve again, and test it out (pop in the end with a paper clip or needle, it probably either has something in there preventing it from closing all the way, or could be a defective valve (not likely). I'm not sure how the warranty works on the valves, they may claim contaminated fluid. Speaking of which, I don't know how you are with maintenance, but you may want to replace the filter & fluid again, and flush your bores.

    The fact the lift arm stays up, and it takes an added effort to get it down, is another issue to address....I barely have my plow hat on right now, so I'll get back to you on cylinder issues. They're not related....I'm 99.9% sure of that anyway.
     
  5. grec-o-face

    grec-o-face Senior Member
    Messages: 485

    This morning I drove to work with the blade on the truck and the controller disconnected. My 10 mile drive resulted in blade creep again. So we can eliminate the controller as suspect, correct?

    I'll try to pull the valve and test it this week. Most likely, Wed night.

    I'm pretty good about maintance. Fluid and filter before every season. What do you mean when you say "flushing the bores"?
     
  6. Arc Burn

    Arc Burn PlowSite.com Addict
    Messages: 1,138

    Pull the S1 and clean/inspect it before buying a new one.Also,loosen the gland nut on your lift cylinder and run the plow up and down several times and retighten,seals in the nut are probably dry and the nut could be a hair tight as well.
    And no,these 2 problems are not related unless the lift cylinder is leaking.
     
  7. grec-o-face

    grec-o-face Senior Member
    Messages: 485

    Will do. What's the recommended cleaning agent for the valve? Brake clean seams a bit harsh. There are NO signs of an external leak.
     
  8. kimber750

    kimber750 PlowSite Veteran
    Messages: 3,611

    Agree with Arc, would bet it is a piece of dirt or torn o-ring.

    As far as not going down all the way, if I read correct you do not have the return spring hooked up? How hard is it to push down the rest of the way?
     
  9. grec-o-face

    grec-o-face Senior Member
    Messages: 485

    Correct.
    It took some effort, but it wasn't terribly hard. One guy, one-handed. I think it's OK.
     
  10. Arc Burn

    Arc Burn PlowSite.com Addict
    Messages: 1,138

    Kerosene but i have to admit that i use brake clean myself.
     
  11. grec-o-face

    grec-o-face Senior Member
    Messages: 485

    I pulled the valve and inspected/cleaned it. (brake clean & air) Still have a case of the creeps.

    The valve seamed to move freely without trouble. No sign of debris.
    I just don't know if it is fully seating when it's closed...
    What's my next step?

    A new valve?
     
  12. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Hate to say it but replace the valve again Aaron. It's the only recourse other than an issue with the lift ram itself.

    Be sure it's a genuine OEM valve also.
     
  13. grec-o-face

    grec-o-face Senior Member
    Messages: 485

    Alright then. I'll pick one up and report back - it may be a while, just got slammed with some side jobs.

    Thanks Mike.
     
  14. grec-o-face

    grec-o-face Senior Member
    Messages: 485

    Better late than never.

    I replaced the S1 valve (with a genuine Fisher part) and it seams to have fixed it. I guess time will tell.

    Thanks guys.
     
  15. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Excellent. And if you find it happens yet again, replace the lift ram. It's "shedding" internally thus putting debris back through the S1 valve.
     
  16. grec-o-face

    grec-o-face Senior Member
    Messages: 485

    Will do. Thanks!