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lift cyl.???

Discussion in 'Boss Plows Discussion' started by grf_1000, Jan 29, 2010.

  1. grf_1000

    grf_1000 Senior Member
    Messages: 295

    lift cyl. went on me yesterday. i've had it happen before but never like this. no leaks,bends,pits,scratches no tweaks. ok heres the thing, i used the plow for 4 hours then pushed to the pile and stacked,hit R and backed up,but the plow went to the ground. tried lifting the plow and it lifted weight off the front of my truck. it was like it had down pressure. needless to say i had to jack it up and tie it off to get it to the shop. when i tried lifting it, it was like using the smart hitch to mount it. i unhooked the smarthitch to test it,took the valve out and plugged, even unhooked the return hose to diagnose the problem. the only thing left was the the lift cyl itself. long story short, anyone else ever have this happen ?? or have a one that went bad that wasnt leaking or bent? i replaced it all back up in running in an hour.
     
  2. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Like any type of cylinder you can lose a piston seal for no justifiable reason sometimes.

    Easy way to test them on the Boss' is to simply remove the smart hitch hose from the top port on the lift cylinder and press the lift function. If it spews fluid from the cylinder port you know the fluid is getting by the lift piston.
     
  3. grf_1000

    grf_1000 Senior Member
    Messages: 295

    yep that was the second thing i did, i was hoping it was a just a valve stuck or went bad on the valve body,,,, no such luck. i had just never seen one go bad the way this one did.
     
  4. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Just had a 1 month old MVP Plus do the very same thing a couple weeks ago on a wing cylinder. No leaks runs drips or visible damage, just wouldn't move the wing. Blew the piston seal out.

    One tip I'll provide is to check the pump relief setting. If it's too high it contributes to blown rams. Never set it higher than 2300 PSI at full relief.