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Ford L8000 side wing problem

Discussion in 'Truck & Equipment Repair' started by Orange pumpkin, Apr 3, 2011.

  1. Orange pumpkin

    Orange pumpkin Junior Member
    Messages: 4

    Hello was hoping this is the forum to be on for asking for help on figuring out the problem with my 82 ford L8000 county plow trucks side wing slamming into the pass door caving it in afterusing wing and coming to a complete stop .It doesnt happen all the time but when it does its ruined my pass door twice now .Ill come to a complete stop before lifting the wing .Ill back up as to get the blade out from under any possible pressure against the wing and just as i knudge the lift control its like whamm right into the door taking out the mirrow and caving in the door . I believe the truck is equiped with 12 ft reversible blade and 8 ft side wing . I purchased what a friend said was a cushioning valve with a knob for adjusting the rate of flow that he says is what is missing on the side wing .There are only 2 lines to the lift cyl and no other valve in line other then where the conn connect on the hyd up frt . What i need to figure out is why does the pressure get so high that it picks that wing up like a toy and flings it ,otherwise at other times it works normal ...ANYONE willing to take a stab at this .? The so called cushioning valve i have is a small 3x4 in square unit with another 2x3 unit attached to it which has the adj knob .On this unit there is a inlet for pressure and outlet normal 3/4 in hyd lines plus a small steel 3/8 line that i do not know where to hook this to . All help would be appreciated in fixing this problem as doors are getting expensive .My email to answer me on this question is beanyandcecil_54@hotmail.com thanks in advance the orange pumpkin
  2. blee1ash

    blee1ash Senior Member
    Messages: 107

    On the ones I have operated there is a bracket with a rubber bumper where the heel (outside) of the wing contacts when raised. With that bumper, and if you raise the toe ( inside) of the wing first, there is no way it can contact the door. Do you have the right length of push pole on the wing, and is the shear pin on the push ploe not broken?
  3. Orange pumpkin

    Orange pumpkin Junior Member
    Messages: 4

    82 Ford l8000 side wing problem

    There is nothing wrong with the arm or pins its in the hydraulic pertaining to the wing only as this happens only when plow wing is at rest and you are just knudging the lift handle it will violently throw the wing into the door bending that little half bottle shape stop bracket which the blade contacts as a stop thank you for replying
  4. pohouse

    pohouse Senior Member
    Messages: 322

    Check to make sure there is no air in the cylinder and two hoses. Cavitation within the cylinder could cause a cylinder to act violently. Have any control valves been replaced recently?

    A cushion valve is used to release high pressure from the cylinder. It is installed between the control valve and cylinder. If the wing hits something, a violent compression of the cylinder occurs. That pressure is released through the cushion valve, which bypasses the hydro fluid to the other side of the cylinder. The cylinder can move (or cushion) without operator input. Yes, you should have one. I'd be surprised if the truck didn't have one already. I don't think adding the valve is the solution to your problem though.
  5. Orange pumpkin

    Orange pumpkin Junior Member
    Messages: 4

    Thanks for input .So i know on this cushion valve my friend gave me that i hook it into the pressure hose side to lift wing then T into the down side of cylinder (returnside ) correct ? But this valve also has a small 3/8 steel line with pressure fittings ....where would one route this line ? What setting do i adjust the flow valve too? Ive enclosed a few pictures of this cushion valve that i have .And no there is not one in the lines anywhere or mounted on control valves . Thanks ,wayne

    cushion valve for plow trk 004.jpg

    cushion valve for plow trk 001.jpg

    cushion valve for plow trk 002.jpg
  6. blowerman

    blowerman PlowSite.com Addict
    Messages: 1,275

    I'm under the impression you think there is to much pressure? If you turn the pressure down, then the problem is solved.....? I have a 94 L8000 with 12 ft. front & 8 ft. side wing, I'll look at the set up today and see how it is set up. If you are not plowing streets, they are worthless and more often just in the way.
    (unless you have a really good driver, then they can really move some snow:most guys don't know how to use a wing)
  7. pohouse

    pohouse Senior Member
    Messages: 322

    I've done a lot of reading on central hydraulics for my own truck but I don't consider myself a hydraulics expert. I'll give you my best guess. Recommend double checking this info with a hydraulic shop.

    I think you have two devices there. A flow control (with the adjustable knob), and a cushion valve. A flow control is different than a pressure regulator. The flow control will control speed of the cylinder, not necessarily the pressure, especially under load.

    The cushion valve has three ports. IN, OUT and BYPASS. The flow control is probably mounted in the IN port. The OUT (has tape on the fitting) would go to the cylinder. and the port with the metal line IMO is the Bypass. On single acting cylinders, that would probably go back to the reservoir or somewhere the excess fluid could be re-entered into the system. On double acting cylinders it can go to the opposite side of the cylinder. The port on the opposite side of the OUT port (has several nuts on it) is to adjust the back pressure required to bypass. Loosen the first nut, then turn the center bolt. Some have an allen type head, others use a flat screw driver. Most valves I've seen, if you turn the bolt IN it raises the pressure required. If you turn it OUT it reduces the pressure. The pressure should be set under the rated pressure of your cylinder or hoses, but above the normal pressures caused by using the wing.

    In other words, if the setting is too high, you'll blow a hose first, or break a mount before the cushion valve opens. If you set too low, when pushing snow with the wing (normal use) it may bypass and cause the wing to retract.

    Check the return line from the cylinder. Is it the same size hose on each side of the cylinder? Any crimping or restrictions that could cause a buildup and sudden release of pressure? Might check if any mechanical binding is occuring also.

    Again, the cushion valve only activates when there is sudden back pressure. Sorry for the long post. Hope this info is helpful.
  8. pohouse

    pohouse Senior Member
    Messages: 322

    Just a clarification. Use a "T" to connect the valve BYPASS port to the opposite side of the cylinder. It will not work if both hoses from the cylinder are plumbed to the valve.
  9. Orange pumpkin

    Orange pumpkin Junior Member
    Messages: 4

    L8000 side wing problem

    Thank you pohouse and others for the replys . I also did some more research and you are correct at what i have . The valve is a flow control on top of a cushion valve .I stopped by a local county shop and they have the identicle setup on one of theyre old stand by trucks .The mechanic said you definetly should have one a flow and cushion valve in line before your pressure port to lift cylinder >AS You stated po house as this will safe gaurd the truck against the kind of damage my truck has endured twice now, not to say it scares the bejebbies out of ya when your sitting still and it decides to crush your door .He said it has happened to multiple drivers with other trucks they have owned especially with over sized hyd pumps where they use extra attachable equipment .He mentioned like what you said pohouse to plumb the steel 3/8 line into a T on the return side of cylinder ...its this steel line that saves you from the damage and redirects the over amount of pressure caused from the force of the snow against the wing when pushing . I am going to plumb this valve assy into it later this week . Iam grateful to having found this forum site and to you POHOUSE and the others that took the time to right me on my problem and to the mechanic at marinette county wisc garage for his help too I believe a side wing is one of the greatest pieces of equipment to have on your truck .For me its a god send as i have a mile long driveway that always gets drifted shut on the north side and that wing has helped keep the snow piles cut down and far away from the drive and from drifting shut . Hoping winter is almost done here in the northern wisc and that the weight limits go away fast so i can replenish the lost gravel from plowing .....Thanks again to all of you who replied to this problem !!!:salute: