1. Welcome to PlowSite. Notice a fresh look and new features? It’s now easier to share photos and videos, find popular topics fast, and enjoy expanded user profiles. If you have any questions, click HELP at the top or bottom of any page, or send an email to help@plowsite.com. We welcome your feedback.

    Dismiss Notice

Fisher SEHP Puzzle

Discussion in 'Commercial Snow Removal' started by BigYotaLuvr, Mar 9, 2005.

  1. BigYotaLuvr

    BigYotaLuvr Junior Member
    Messages: 6

    I have a tired Fisher SEHP rig on my T-100. It plows great but recently I am chasing gremlins. :gunsfiring: I downloaded the Mechanics Guide from this site and found that initially I had a bad S2 cartridge. I replaced that and now I have the situation where when the rig is cold everything works fine but upon warming up (twenty minutes or so) raising becomes intermittent and chugging, left command send the plow right and eventually no response at all. I let it cool down and we can start all over again. :confused:

    I had the motor checked at an excellent Ignition shop and he said it was fine. I have a brand new heavy duty solenoid. Is it possible that the pump is tired and when the fluid warms it is slipping and or binding? I can tell that there is a heavy current draw when it doesn't respond.
    Ideas and suggestions welcome. Should I tear down the pump, and if so, what wear should I look for? I don't have the means to pressure test the pump. :help:
  2. rondoga

    rondoga Junior Member
    Messages: 27

    Did you check your s3 valve???
  3. BigYotaLuvr

    BigYotaLuvr Junior Member
    Messages: 6

    S3 was OK!

    Yes, I did. The coil had the correct 6.7 ohms of resistance and when I put 12v on one leg and a ground on the other as per the manual I could see the cartridge actuate. The S1 was fine too. It was the S2 that wouldn't budge with electricity or manually. I am now wondering if it is the poppet valve... but why when it gets warm?

    Since it is such a simple procedure I can check it again but it seems strange that it would be that so soon but worth a second look :salute:
  4. rondoga

    rondoga Junior Member
    Messages: 27

    Ive been having similar problems with mine
    but my problem is contaminates clogging the valves
    when mine slows down its the filter on the pump is clogged
    when it stops responding (no lift no left it just turns to the right )
    Its always the s3 valve stuck .......
  5. Crash935

    Crash935 2000 Club Member
    Messages: 2,377

    Yota, go back and check the ohms on the S2 coil, sounds like it is overheating and starting to fail, also look to make sure you didnt pinch a wire under the cover when you put it back on.

    rondoga, sounds like you might want to check the angle cylinders, If its metal that you keep getting on the filter a retainer ring has broken, if its black and rubbery, its a packing going. Drain each cylinder into a fine filter screen (type from a paint shop works best) and see if something comes form either of them.