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Uni-Mount Blade lowers by itself

Discussion in 'Western Plows Discussion' started by GMC99, Dec 29, 2011.

  1. GMC99

    GMC99 Senior Member
    from 60188
    Messages: 753

    My uni-mount straight blade functions properly, but when raised, it will slowly fall by itself, I also hear a hissing noise coming from the pump when its falling.. Already tried adjusting the quill... Any suggestions?
     
  2. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Dirty/defective S1 valve most likely. Pull it out and try and giving it a good cleaning while stroking it's internal spool with a small screwdriver and then reinstall. If it still leaks down replace the valve.
     
  3. GMC99

    GMC99 Senior Member
    from 60188
    Messages: 753

    Which one is the S1 valve? I pulled the cover off today, and noticed that the top right solenoid is hot to the touch?? And when you say valve, you mean the valves behind the solenoids correct?

    Thank You for the help
     
  4. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    S1 is the top right hand valve, same one that you stated was hot. If you leave the plow in float for prolonged period yes the S1 coil will get rather warm and that is what shortens coil life so refrain from doing that when it isn't needed. If you're the type that drops the plow when leaving the truck run to step out for a while, always be sure to bump the controller out of float (if it's in) to prolong the life of the coil. Helps the controllers last longer as well.

    To remove the valve for cleaning/replacement- remove the nut, slide the coil off the valve stem and simply unscrew the valve from the manifold.
     
  5. mishnick

    mishnick 2000 Club Member
    Messages: 2,243

  6. mishnick

    mishnick 2000 Club Member
    Messages: 2,243

    There are three electrically controlled valves: S1, S2 and S3. These are the ones under the black coils. There are other types of valves like crossover relief valves and poppet check valves but your problem has to be in the S1 so you don't need to worry about the others at this point. Since your coil has been hot have a look at it for cracks or other damage. Also, when you pull the nut and coil off take note of how easy the coil slips off the cartraige. If it comes off easy that's a good thing but if you have to twist and pull hard to get it off the stem of the valve is swollen or bent and needs to be replaced.