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

MM1 SEHP Different left to right

Discussion in 'Fisher Engineering Discussion' started by MRBachand, Oct 28, 2009.

  1. MRBachand

    MRBachand Senior Member
    Messages: 198

    When I go right and stop lever action to the right, it is a nice quiet smooth stop.

    When I go left and stop lever action it LOCKS MOVEMENT FAST, creating a violant in comparison stopping action.

    Why would this be? Everything appears to be working perfectly.

    Which one is normal?
     
  2. plowinginma

    plowinginma Senior Member
    from MA
    Messages: 326

    it depends on which controller you have.. I would asume you have a joy stick? It is supposed to be harsh with a joy stick MM1. Could be a pressure relief valve needs to be adjusted/replaced more than likely..
     
  3. RepoMan207

    RepoMan207 PlowSite Fanatic
    from Maine
    Messages: 5,037

    The relief valve may need adjusting, one if not both rams are starting to fail, air bubble, low fluid level, old fluid, fluid contamination......

    When was the last time you checked your fluid level, or for that matter changed or flushed it? Did you have the pump apart at all recently? When was the last time you replaced the angle rams?

    Edit: I was going to make a comment to the controller statement, but I was just reading some of my old notes....It's in there. The Fish Stick will alleviate that problem. Might want to try a Fish Stick if your not already using one. The dealer may allow you to test one out in the parking lot before buying it....I know my does.
     
    Last edited: Oct 28, 2009
  4. plowinginma

    plowinginma Senior Member
    from MA
    Messages: 326

    "You have to check the fluid???? I thought they just plug in !!! "
    I have heard this statement before.. LMAO
     
  5. RepoMan207

    RepoMan207 PlowSite Fanatic
    from Maine
    Messages: 5,037

    "What do you mean my truck seized it's engine.....Nobody told me I had to change the oil."
     
  6. Arc Burn

    Arc Burn PlowSite.com Addict
    Messages: 1,139

    It's the Poppet Check Valve and fairly normal on straight blade Fishers.
     
  7. RepoMan207

    RepoMan207 PlowSite Fanatic
    from Maine
    Messages: 5,037

    I believe the Poppet valve is for the lift ram only, I may vary well be wrong about that.
     
  8. Arc Burn

    Arc Burn PlowSite.com Addict
    Messages: 1,139

    After installing a bunch of new straight blades and noticing this violent "jerk" a few years back i called one of the techs at Fisher and they said it's just he way the PO valve opens and shuts and that it was normal.
     
  9. RepoMan207

    RepoMan207 PlowSite Fanatic
    from Maine
    Messages: 5,037

    .....Same answer I got pretty much, something about closing two valves at once vs just one going in the other direction. I was also told the Fish Stick has a "soft something ur other" that closes the valves slowly in either direction every time preventing the violent jerking motions. The Joystick doesn't have this technology....or so I have been told.
     
  10. plowinginma

    plowinginma Senior Member
    from MA
    Messages: 326

    You are both correct LOL .. The popet valve is part of the hydraulic schematic for both functions Lift and angle right...His problem is more than likely the crossover relief valve..
    Even if he changes his controller to a fishstik the problem is still there just not noticed..
     
  11. MRBachand

    MRBachand Senior Member
    Messages: 198

    Fluid is a week old. Did a complete THOUROUGH Flush, as I rebuilt my lift cylinder and replaced a ram hose. One ram was replaced a few years ago and looks perfect, other ram looks good, but older.

    I'm not going to worry about it, but Just wondering why... It seems pretty normal, just why one way, and not the other?

    To double state :

    Only does it when angling to the left, NOT to the right.
     
  12. RepoMan207

    RepoMan207 PlowSite Fanatic
    from Maine
    Messages: 5,037

    I had this exact problem after I rebuilt my plow last year. If you didn't have this problem before, I would bet you have an air bubble. Otherwise, what everyone has stated above is more accurate.
     
  13. MRBachand

    MRBachand Senior Member
    Messages: 198

    I'm pretty sure its always been this way for the 4 years I've owned her.

    Every now and again i can move the plow by hand (angle wise) a bit before it catches, so I suspect its one of the relief valves stuck, or out of calibration. I'll diagnose it alittle bit more as I go.

    Does anyone know is it normal to violantly stop, or normal to smoothly stop?

    I think I can sometimes force it by hand LEFT (drivers side plow towards truck) a few inches before it stops on its own, This made me think I had air in it, I cracked the lines and thought I got it out, and I didn't really play with it too much afterwards.

    But now that I'm thinking more about it, it may be more dependant on weather I last used the left angle or the right angle motion on the controller.

    I'm draining the ATF I have in it now in a few days and going with Fisher Blue, the ATF was just a means to flush out the crap that was in there, resembling grey goop.

    I've given this thing the far most attention this year, rebuilt lift piston, and all the pins.

    I'll take a pic of my old pins when I'm done changing them all out.

    Somone really hit something hard with this thing before, blew out mounting holes, one of my ram (driver side) pins looks like a banana, and my Center pivot I changed out today has a good bend in it also.

    These pins must all be originals as they are all garbage... 5 changed, 8 to go.
     
    Last edited: Oct 28, 2009
  14. Arc Burn

    Arc Burn PlowSite.com Addict
    Messages: 1,139

    Re-read my post,not being arrogant,i know what i'm talking about,I don't want you chasing a problem your never going to fix.
     
  15. Crash935

    Crash935 2000 Club Member
    Messages: 2,377


    Arc Burns knows what hes talking about so go with what he said.
     
  16. MRBachand

    MRBachand Senior Member
    Messages: 198

    Can you elaborate more about this poppet check valve? I like to understand how my equiptment works.

    Does each coil/cartridge have its own Poppet? Or is there only one per unit? Is it the valve that gives when you force the pistons? (IE, TREE or CURB)

    Thanks!

    I'm completely new to the word poppet, Albeit, its fun to say. If it may be a common hydraulic term, its new to me. Thanks again.
     
  17. plowinginma

    plowinginma Senior Member
    from MA
    Messages: 326

    No there is only one popet on a Insta act set up... Basically it is a short cut for the hydraulic fluid.. if that makes sense.. there are 3 cartridges.. however they don't work the way most think they work.. such as one for up and down one for left etc... If you understand hydraulic schematics you could look on the fisher web site and see exactly how they function.. and the tree or curb is controled by the cross over relief valves.. also shown on the schematic.. hope that helps..