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Sno-Pro slowly lowers on its own.

Discussion in 'SNO-PRO PLOW AND ACCESSORIES by Curtis' started by 600rrpilot, Nov 7, 2012.

  1. 600rrpilot

    600rrpilot Senior Member
    Messages: 108

    Need some help with this one as its been doing this since last season and its no longer just an annoyance but rather a safety hazard. Lets say I leave a site and raise the plow. Well a few minutes later if I dont lift it again, it will be on the ground. Not a huge deal but if I'm doing 50 on the highway and get distracted and dont raise it and it catches an edge on manhole, well that could hurt.

    I have had the spool valve out and inspected the seals and it seems as though some of the teflon backup rings are a little worn out. But to be honest I'm not even sure if that could be the source of the problem. I would think that the oil is just seeping past the seals causing the plow to slowly lower under its own weight. But is that possible? Im not 100% sure how these solenoid valves work. Is it possible that the magnets that control the valve arent seating properly or something? Or does this sound like its definitely the seals on the spool?

    Angelo......whats your opinion? anyone else ever work on the internals of these?:mechanic:
  2. MadLion90

    MadLion90 Member
    Messages: 40

    Not sure if this helps but I had the same problem on my 3000 2 years ago. Same symptoms, it would lower slowly by itself. Usually it would take about 5 mins to hit the ground from a full raise position and got worse the more I used it. It ended up being a bad valve. Pretty sure it was the Float Valve which is the one by itself on the blade side of the manifold (only has 1 coil). I swapped it with a similar one off an older 2000 plow to get it working (middle of night/storm deal) and later bought a new one ($120) and has worked since. You can always try cleaning it first as recommended in the manual with "Mineral Spirits then dry with compressed air". I actually have to replace the Jack Retract Valve as well cause I think that's why my plow is on the ground after the summer.

    It is very easy to change, just unbolt retainer nut, slide off coil, unbolt valve from manifold. Put a rag under the valve to catch some fluid that will leak out. Helps if you jack the blade up to get the fluid to stay on the reservoir side. Install is reverse. Check what your coils say (Detrol or Sterling) and buy the right valve. I have a diagram of the different types of valves with how to tell which one you have. PM me with an email and I'll scan/send it to you.

    Hope this helps your problem.
  3. MadLion90

    MadLion90 Member
    Messages: 40

    Forgot to mention that if you don't want to spend the $120 upfront not knowing if that is in fact the problem (like me), then you could just swap it with the Jack Retract Valve which is the middle one (top to bottom) on the other side of the manifold. Basically there are 2 long valves and 2 short valves. Swap the short ones and check if it works. Remember to leave the coils in the same place or you will end up reversing the functions.
    Note: If your jack loses pressure as I think most end up doing on these plows, then you may just be swapping a bad one for a bad one (the reason I used one off the other plow which I knew worked). However, if it holds the plow up better than before then its def the valve.