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Slow Speedcaster

Discussion in 'Fisher Engineering Discussion' started by Tomas090, Sep 9, 2009.

  1. Tomas090

    Tomas090 Member
    from Maine
    Messages: 63

    Had this problem last year and never resolved, made it through the season slowly

    7' Speedcaster circa 1980 0r so, belt driven pump

    Works fairly well at beginning of day, for about two hours and gets progressively slower

    By the end of day the dam blade won't even angle, sometimes making sounds like bending steel

    Have cleaned and changed all fluids, don't know if or where any filters may be, have done the moving of pistons side to side while disconnected, also turned vertical piston upside down and cycled

    Seems as oil gets hotter and thinner pump get weaker?

    Any way to test this without special equipment

    Thanks for any help
     
  2. ss502gmc

    ss502gmc Senior Member
    Messages: 473

    Could be that the valve body is seeping when it gets hot. I had this happen before and spent the $250 on a new pump and changed nothing. I got a new valve body and it worked fine. jmo
     
  3. Tomas090

    Tomas090 Member
    from Maine
    Messages: 63

    Been checking everything for leaks, nothing external around valves? Any better way of checking?

    Thanks for suggestion
     
  4. 2COR517

    2COR517 PlowSite Fanatic
    Messages: 7,115

    When those valve bodies leak, they leak internally. Non rebuildable. If this is your primary plow truck, you probably need a new valve. Not cheap, but less than a new plow.
     
  5. Tomas090

    Tomas090 Member
    from Maine
    Messages: 63

    Do they leak in a manner that allows fluid to enter the wrong chamber, or actually leak fluid externally?

    I can find no evidence of leak and no loss of fluid

    Thanks
     
  6. ss502gmc

    ss502gmc Senior Member
    Messages: 473

    Basically what happens is when the fluid gets hot the seals expand and when they are worn out they allow the fluid to slowly leak past the seals in the valves "Internally" which means you will not see an external leak and when that occurs there isnt enough pressure going out to the plow pistons so that is why every thing moves slowly especially when everything gets hot. Try ebay for a used valve. Someone may have one that may not be perfect but way better than the one you have now. I got one off ebay a few years ago for $75 and it worked good.
     
  7. Tomas090

    Tomas090 Member
    from Maine
    Messages: 63

    Thanks

    Could it also be a weak pump that has the same problem when hot?

    How do I test pump or valves

    Also, anyone have the procedure for draining and refilling the system with clean fluid, that can't hurt
     
  8. ss502gmc

    ss502gmc Senior Member
    Messages: 473

    Well you can remove the pump and pour the fluid out or suction the fluid out with a turkey baster or a pump but its more effective to just remove it. Then remove the quik connects off the ends of the hoses and let them drain out and move the joystick around to drain the valve body and then remove the quik connects from the plow pistons and move the a frame back n fourth to get the fluid out and dont forget about the lift piston and make sure its all the way down to get all the fluid out. Then reconnect everything and hook up the plow, then fill the pump with new fluid then start the truck and operate the plow in all directions to bleed the system being sure to constantly check the fluid level as it will go down quick and when everything is moving as it should and the fluid is up to the full line your DONE!!!
     
  9. ss502gmc

    ss502gmc Senior Member
    Messages: 473

    Also to answer your other questions on testing as far as i know there is no way to test them, when i dealt with this before i replaced the pump and had very little change and then the valve and that did the trick.
     
  10. PaulT

    PaulT Junior Member
    Messages: 19

    I have the same problem. Happened to have a brand new spare tranny cooler hanging around, so I installed that inline on the return line. Helped quite a bit, but it is just a band-aid. Still need a new valve body.