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Fluid leaking out of cap

Discussion in 'Boss Plows Discussion' started by Langtlnd, Mar 3, 2014.

  1. Langtlnd

    Langtlnd Junior Member
    Messages: 5

    I have a boss 8'6" straight blade and have been have the issue fluid blowing out of the vent cap, to the point where sometime the blade will shudder or not work. I had a problem with wiring early this season, and replaced some of the wiring due to a rodent problem. For part of the season my smart hitch didn't work until I got the correct diodes for the ground jumper and switch jumper. I have replaced the vent cap and checked over all the wiring and am still losing fluid out the vent cap. I am looking for any help on what maybe causing this issue and how I can fix it or do I need to pull the pump and bring it in to have it worked on. Thanks.
  2. framer1901

    framer1901 Senior Member
    Messages: 805

    You need to have someone run the plow in all directions while you are watching - have them move it all the way left, right and up - keep the pump running to build pressure in the system - watch the valve body and see if it's leaking there, at the solenoids or hoses.

    Very weird to be coming ou the vent.

    We had one recently that was leaking at the valve body, old o ring or just loose, don't know or care, tightened it and it don't leak no more.
  3. finn

    finn Junior Member
    Messages: 5

    If it is leaking out the vent on the cylinder, the seal has failed. A seal kit is available from Boss, but a new cylinder isn't much more (my dealer gave me a good price- he's busy and didn't want to screw around rebuilding my old cylinder)
  4. Jersey Push

    Jersey Push Junior Member
    Messages: 28

    I have the same problem! Been chasing this for TWO seasons now. I took it back to the dealer the end of last season and all they did was put teflon arount the threads of the cap and said I probably had too much fluid in the resquior. But its getting worse too the point the plow shutteres from cavitation due to lack of fluid. So all i donif keep filling it up. still trying to find out whats going on.
  5. obj1

    obj1 Junior Member
    Messages: 4

    If it it is leaking out cap, it is most likely over full. if not over full, return line in resivoir may have bad o-ring or missing defuser screen. sometimes, however a leak that looks like its coming from cap is actually coming from bad o-ring on back side of power unit. loosen power unit, move it out and clean fluid mess up. run pump and re-inspect rear of unit for leak.
  6. kurtandshan

    kurtandshan Senior Member
    Messages: 323

    Please be sure when disconnecting your plow from the truck you power down the headgear all the way with the switch. Pushing it down by hand allows air into the system and is vented out the vent cap when operating the plow pulling fluid with it.
  7. Langtlnd

    Langtlnd Junior Member
    Messages: 5

    Figured out the problem, I had a bad o ring on angle cylinder valve that was leaking down on and by cap.
  8. Jersey Push

    Jersey Push Junior Member
    Messages: 28

    I just asked my dealer about this he said I maybe letting the headgear "fall" or "drift" down on its own when unhooking which is causing air to get into the system every time. He suggested to us the switch to retract the ram all the way for storage. We'll see supposed to get some snow this weekend.
  9. Citytow

    Citytow Senior Member
    from phila
    Messages: 548

    read the directions . power the headgear all the way down when your unhooking. if not , air enters the system. but they self bleed , so wtf? may be contaminated fluid