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Smartlock cylinder alternative?

Discussion in 'Boss Plows Discussion' started by Spitz, Dec 2, 2008.

  1. Spitz

    Spitz Senior Member
    Messages: 192

    Was in a hydraulics class a few years ago (general course for auto tech credits). Was wondering if anyone had any hyrdaulics experience? What i mean is i KNOW there is a way you could make a boss V plow without smart locks to hold the wings out. On our wrecker (the wheel lift specifically) the ONLY way any functions work is with pump pressure, there is a pilot circuit that will NOT open unless you put pressure to the valve, then it will function normally. Has anyone thought about this? I understand this may be not feasible as it may cost more than what the cylinders cost, but it can be done, i know.. What do you all think?
  2. Ramairfreak98ss

    Ramairfreak98ss PlowSite.com Addict
    Messages: 1,885

    honestly, i think the "standard" pistons on the boss are just bottom of the line, most hydraulics like you say, do "lock" or stay put at very least.

    Whens the last time you drove a tractor/loader, dumped the bucket half way, and the momentum of the bucket material, slammed the bucket forward for you? it doesnt happen lol.

    Ive never seen hydraulics that can apply pressure but be pulled out, and yet still can have the pump reverse pressure to them and be pulled back in, its weird.

    Smartlocks i doubt are anything special, probably just gets you back to " ordinary" pistons
  3. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    If I'm following your thoughts correctly the priority circuitry wont do any good on the wing cylinders...they'll still be pulled out by the snow load regardless as it'll simply pull on the piston whether your locking/closing the fluid port to the cylinder or not...which they are blocked anyway in the stock configuration by the wing valves and the load still pulls the wings out. Thats the entire reason the SL's are needed in the first place, since you can't hydraulically lock a single acting cylinder in both directions.
  4. Spitz

    Spitz Senior Member
    Messages: 192

    Ah thats where my thinking is skewed, they are single acting cylinders arent they.. Well i guess that throws that idea out.. Whats actually locking the cylinder from moving out on a smart lock cylinder? Is there some sort of mechanical device?
  5. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Yes there is a valve internal to the SL that's activated when an attempt is made to physically PULL the ram out of the cylinder. Which would be the case during back dragging maneuvers.. Any other time the ram is always either being PUSHED out of the cylinder (by hydo force) or being PUSHED in by the wing retract spring. The SL valves do have a relief built into them that will release the cylinder when a certain threshold is reached, about 3500 psi IIRC.

    A rather simple innovation for an otherwise problematic condition. No need for extra valves, hoses, fittings, and related wiring such as on a plow with double acting wing cylinders.
  6. themechanic43

    themechanic43 Junior Member
    Messages: 24

    That's the beauty of SL's. The internal relief valve. On dual acting cylinders, such as west & fish, I've seen backdragging hit something solid and tear the rod right out of the cylinder.
  7. Spitz

    Spitz Senior Member
    Messages: 192

    That would be a bad day.