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mm1? angle left slow and hard

Discussion in 'Fisher Engineering Discussion' started by deeznuts, Jan 1, 2008.

  1. deeznuts

    deeznuts Junior Member
    from nh
    Messages: 8

    i have an older 8' hd minute mount on a 96 dodge 2500. when i put it up or to the right it is nice and fast. When i angle it left its very slow and will get stuck sometimes. i took the three coils and valves out, cleaned the heck out of them and the whole valve body, changed the fluid and filter, new angle pistons and motor. changed the coils too but nothing helped. i then took the lines going to the angle pistons and put them in a bucket, had someone try the angle and when it goes right the fluid comes out the left hose fine but when it goes left the fluid comes out the right hose and when it stops it shoots out the other too. seems like its working against it self when i angle left. really aggravating. can anyone help???
     
  2. deeznuts

    deeznuts Junior Member
    from nh
    Messages: 8

    its not the insta-act its the other. 2 plugs and i forgot to say i changed both plugs with new replacments too
     
  3. rtm038

    rtm038 Senior Member
    from NJ
    Messages: 231

    It could be the crossover relief valve for the right side angle cylinder allowing pressurized fluid to crossover to the left side cylinder hydraulic circuit. This valve could either be stuck in a partially or fully open position.

    Ryan
     
  4. rtm038

    rtm038 Senior Member
    from NJ
    Messages: 231

  5. deeznuts

    deeznuts Junior Member
    from nh
    Messages: 8

    which relief valve would it be looking at the front of the plow. the one under the cover?
     
  6. rtm038

    rtm038 Senior Member
    from NJ
    Messages: 231

    Yes. Look through that pdf. file and read up on how to clean/adjust the various relief valves. It's relatively easy to do. Good luck!

    Ryan
     
  7. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    If it holds the blade angle when it's on the ground with a snow load (doesn't drift) then it's not a relief valve (cross over) problem. More than likely it's the poppet valve.
     
  8. rtm038

    rtm038 Senior Member
    from NJ
    Messages: 231

    .
    Unfortunately he didn't say that it does or does not hold the position while plowing. As for the poppet valve, are you talking about the pilot-operated poppet valve that opens when angling left to allow fluid from the left side cylinder to return to the reservoir?
     
  9. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Yes, if the poppet is damaged or contaminated and can't fully open (or in some cases close) it will restrict the return fluid out of the left angle cylinder, causing the slow left angle.
     
  10. deeznuts

    deeznuts Junior Member
    from nh
    Messages: 8

    yes it doese hold position when plowing.
     
  11. deeznuts

    deeznuts Junior Member
    from nh
    Messages: 8

    when i took the poppet valves out (which are the 2 small allen head caps right) they did look like they were worn. which one would be holding it up? the one on top or on the front?
     
  12. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Then check the poppet check valve next.

    Pull both sections of the valve out (from the side and top of the manifold). Check that the spool isn't bent or dragging in the bore. Check that both the springs are in good condition and make sure the tip on the poppet isn't bent. Clean the passage out really good in the manifold too.
     
  13. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Correct on the allen plugs..

    A problem with either one could cause your issue...

    if the poppet (upper one) doesn't allow the spool (lower one) to move, it will restrict the fluid. If the poppet shifts but the spool is stuck in the bore it will cause the same thing.
     
  14. deeznuts

    deeznuts Junior Member
    from nh
    Messages: 8

    thank you very much. I really appreiciate the info. I will give it a try in the morning and let you know. one more question, when you buy the poppet valve kit doese it have the upper and lower valves ar are they sold seperate
     
  15. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Happy to help deez..
    There both sold as a complete kit.. Fisher p/n 7630K is what you want. Should be around $20-$25 or so..
     
  16. rtm038

    rtm038 Senior Member
    from NJ
    Messages: 231

    B&B: Right, right. I see your point, but I didn't think a faulty P/O check valve would cause fluid to exit both hoses if they're disconnected from the cylinders.

    Deeznuts: In your original post, you wrote "i then took the lines going to the angle pistons and put them in a bucket, had someone try the angle and when it goes right the fluid comes out the left hose fine but when it goes left the fluid comes out the right hose and when it stops it shoots out the other too". What I'm confused about is what you mean by "when it stops". If the hoses are disconnected from the rams, no part of the plow itself is actually moving. So when you say "when it stops", what is "stopping"? Just curious.


    Ryan

    P.S. I'm not trying to be a nag, but I've owned (and worked on) a few Fishers over the years and never had this problem, so I'm just trying to "learn" a little more.
     
  17. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    What he meant by "stop" is when he let go of the control function and the pump was slowing to a stop.. and the S3 valve would be closing also, which will momentarily direct fluid to the left angle hose...totally normal.




    Totally understand Ryan... nothing wrong with wanting to learn...it's an addiction I've had all my life.:D
     
  18. rtm038

    rtm038 Senior Member
    from NJ
    Messages: 231

    B&B, did I read his initial post wrong about taking the hoses off then testing it? Because if both hoses were off, then no fluid would be flowing back to the tank, only out the line that the fluid is being sent to/through. Right?

    Ryan
     
  19. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Correct, but when the S3 closes, it will just for a second direct fluid to the left angle hose port...normaly you wouldn't know it as the right cylinder would have fluid/pressure in it so the blade won't actually "move" from the quick pressure shot to the left cylinder. But with both hoses disconnected, you'll clearly see the fluid "shoot" out the hose for a second.
     
  20. rtm038

    rtm038 Senior Member
    from NJ
    Messages: 231

    O.K., I got it. Didn't even think of it that way.