B7500 HST 3pt lift quit working

Discussion in 'Kubota' started by lutherm, Mar 18, 2011.

  1. lutherm

    lutherm New Member

    4
    Mar 18, 2011
    Went out today to plow my garden, and the 3pt lift has quit working completely. I have had a problem recently, with it, but it would work if I lifted it a little by hand and then hit the raise control. The control would not move to the raise position if the arms were all the way down. The hydraulic oil is clean and full. I turned the control speed knob, but lift still would not work in any knob position.
    Anyone have any ideas? :confused:
     
  2. wjjones

    wjjones Moderator

    May 27, 2010
    Hows the hydro filter??
     

  3. lutherm

    lutherm New Member

    4
    Mar 18, 2011
    I pulled the strainer last night, and it was clean. The UDT oil is clear, and looks like new.
    It has 2 oil filters, but I did not pull them yet.
    The tractor is 10 years old now and has 569 hours on it. I bought it new, and did the regular maintenance. Never had any problems with it till now. The power steering still works, and it works normally except for the lift arms. I don't have any other hydraulic equipment installed. I only use the 3point. Have a rear mount Woods mower, bush hog, box blade, 3pt trailer hitch, rear scoop, plow, disk, and row maker.
    I am planning to wash it today and then pull the top off the HST. Without the 3point lift working, I can't use it for anything, except riding around.::usa:
     
  4. NBKnight

    NBKnight Member

    If it's like my 4500...it has 2 pumps.One runs hydros,the other runs power steeing.Thats why it has 2 filters.Chances are it's a plugged filter.
     
  5. Thomas

    Thomas Supporting Member

    Nov 1, 2006
    Does your booklet mention hyd.screens which may need cleaning.
     
  6. lutherm

    lutherm New Member

    4
    Mar 18, 2011
    Yes, I pulled the Hydraulic screen, it was clean. The fluid is clear and looks new. I doubt a filter could be completely plugged. I pulled a plug next to the control speed knob, and there was no oil there with the tractor running. I loosened the oil line for the aux hydraulics at the front, and it has pressure. The lift arms go up and down very easily with no resistance in either direction, so I think no oil in the piston. I can hear the engine "load up" when the lift lever is moved to raise or lower, so I think the pump is working, but nothings happens to the lift arms. Maybe a relief valve or something stuck open??
    I have the seat off and could remove the top of the HST, which includes the lift arms and piston. Don't have a service manual. Is there any problem, or reason, I should not lift the top and look inside for the problem?
     
  7. wjjones

    wjjones Moderator

    May 27, 2010
    Yep the filter can be plugged enough to stop fluid from pumping i had to replace one on a tractor last year, and that fixed the problem. But you are correct it could also be a relief valve, check valve, etc. Keep us posted.
     
  8. lutherm

    lutherm New Member

    4
    Mar 18, 2011
    3 Point Lift is Fixed.

    :D Found the problem... My sun-in-law, who lives next door, used the tractor to pull my 16' flatbed out of the barn while I was gone. He was not familiar with the problem with the Raise control being locked out if the arms were all the way down. It was his last day off before going offshore for a week. When he got back the next week we discussed the lift problem and he said it wouldn't work when he used it either, but wanted to go take a look. I had the seat and seat bracket all off so we started the tractor and went through all the checks I had done etc, with no success. After about 20 minuites of this, we decided to unbolt the long lift control lever, and then used a wrench to pull the short control lever back, while lifting the arms a little, and the 3point arms came up. My 6'2" gorilla son-in-law had bent the control lever enough that it was not moving the control all the way to the Raise position. I straightened the bent control arm and everything was back to normal. I would have been embarassed, if I had taken it to the dealer, and found out that was the only problem.
     
  9. rsmith335

    rsmith335 RICK THE PLUMBER

    988
    Jun 2, 2010
    Glad you got to the bottom of the problem, a lose nut behind the wheel.:lmao: