3 Point Hitch

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    • #49410
      David Trevino
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        Greetings to all,

        I have a 2004 Farm Pro 2420, and have been somewhat refurbishing it.

        The three point hitch is not raising when I pull the lever. The Hydraulic hose that runs to that lever looks like it is engaging. I can see it move. But the hitch is unresponsive.

        Does anyone have any ideas what the problem could be? I was thinking the lever…????

        Any help would be much appreciated.

      • #49411
        David Trevino
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          Picture of lever

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        • #49413
          David Trevino
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            Picture of hitch

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          • #49415
            Piper184
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              It is a little hard to tell from your photos but it looks like the lift arms are already all the way up.

              Some questions:

              Is the fluid at the proper level in the tank?

              If you have power steering, does it work?

              The lever is connected directly to the control valve, are you saying there is a hose connected to that valve? If so, where does it go?

              There should be 3 detent positions for the lever (down, hold, and up). There should also be an up limiter rod with an adjustable stop. It is supposed to be set so that just as the lift arms get to the top of their travel the stop hits the lever and knocks it out of the up position and causes it to go to the hold position.

              Do you have a parts  manual for your tractor?

              Have you tried putting the lever in the down position and then stood on the lift arms to try and force them down?

              Do you hear the pressure relief valve open when you put the lever in the up position?

            • #49416
              DavidPrivett
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                look like they are up to me too.  There have been times when the height adjuster was not set properly and the piston in the lift got extended beyond where it should sit at max. lift  and gets jammed , if they do not go down this might be the reason why.

              • #49417
                David Trevino
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                  I filled the hydraulic fluid on the back side of the machine. There is a bolt with a square end and an overflow there.

                  The steering seems to work fine.

                  there is a hose that is connected to the front end loader control lever. I believe it’s the fifth hose connected there. If you start at that lever, and follow the hose it winds up at what o believe to be the hitch control level (Pic). When I engage that hitch control lever to R (raise) the hose “moves” as if it was filling with fluid.

                   

                  with the tractor off I can move the hitch arms up and down.

                   

                  maybe it is stuck in the up position…I know when I pull the lever back to Raise the hitch I have to give the tractor throttle or it wants to die. Kind of like it’s working too hard

                • #49418
                  David Trevino
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                    It is a little hard to tell from your photos but it looks like the lift arms are already all the way up. Some questions: Is the fluid at the proper level in the tank? If you have power steering, does it work? The lever is connected directly to the control valve, are you saying there is a hose connected to that valve? If so, where does it go? There should be 3 detent positions for the lever (down, hold, and up). There should also be an up limiter rod with an adjustable stop. It is supposed to be set so that just as the lift arms get to the top of their travel the stop hits the lever and knocks it out of the up position and causes it to go to the hold position. Do you have a parts manual for your tractor? Have you tried putting the lever in the down position and then stood on the lift arms to try and force them down? Do you hear the pressure relief valve open when you put the lever in the up position?

                    I loosened up that stop, it didn’t appear to be doing anything. I have moved the lever to lower, but not yet tried to put weight on it at the same time.

                     

                    no sir I don’t have a manual.

                     

                    i haven’t noticed hearing any pressure relief valve.

                  • #49419
                    DavidPrivett
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                      If it is like mine the pressure relief is in the housing that the 3 point control lever is mounted on. and start at the pump to trace your lines high side is the smaller one, return-suction is larger and it should have a filter or a screen housing in line possibly  under  the floor board.

                    • #49420
                      Piper184
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                        Since your front end loader and power steering work, we know that the pump is working and there is fluid.

                        Typically the fluid comes out of the tank under the seat (this also houses the 3pt. piston) and may or may not go through a filter to the pump. From the pump it goes directly to the diverter valve (sometimes called a priority valve). From there, the steering gets the fluid or if it is not needed it gets passed back to the 3pt control valve.

                        If you have a front end loader it will be inserted into the circuit before the diverter valve. This is usually done with quick connects so that you can uncouple the loader and remove it. You would then connect the two tractor side hoses to each other to provide normal hydraulic pressure to the tractor.

                        The hose that moves is the pressure line leading from the loader valve back down to the diverter valve. The fact that it moves is telling us that there is a restriction at the far end of the circuit and the hose is being pressurized and swelling slightly. This is normal.

                        Once the fluid leaves the diverted valve it heads to the 3pt control valve. This is usually a hard pipe but it is possible you have a hose there too. Inside the control valve the fluid either gets routed back to the tank through the pressure relief valve (hold or down positions) or to the lift cylinder (up position).

                        Since the cylinder is a one way only cylinder, there are two ports. One brings fluid in when the lever is in “up” and is blocked when the lever is in “hold” or “down”. The other port is connected to the flow control knob (under the seat at the front of the tank). Fluid then goes back to the control valve where it is blocked in the “up” and “hold” positions but is allowed to flow back to the tank in the “down” position.

                        By design the 3pt. can not put down pressure on the arms, it can only lift them. The only down motion is caused by weight on the arms, including the arms themselves. It is possible to force the arms up no matter what the position of the control valve is or whether or not the tractor is even running.

                        Take a look at the diagrams here: https://www.circlegtractorparts.com Just go to the online parts store and choose the make, model and engine number in the drop down boxes. Then go to the hydraulics section and click on the diagrams and you can see the whole system.

                        Usually whenever a cylinder hits the end of it’s travel it causes the pressure relief valve to open and you hear a whine or growl out of the hydraulics system. This is usually accompanied by a drop in engine RPM as it picks up a greater load. This is all normal and the since your engine needs more than idle RPM to do this indicates it is working as it should.

                        As Dave Privett mentioned it is possible that your internal piston has extended beyond it’s normal “maximum” and has become jammed in full up. If this has happened no amount of weight will cause the arms to lower. Usually the equipment end of the arms travel from a few inches above the ground to about 30″ above the ground.

                        First thing to do is to make sure the flow control knob under the seat is backed off at least a few turns. From sitting in the seat and looking down, clockwise will close the valve and cause the down movement to slow down or even stop if turned all the way. Counter clockwise direction makes the arms drop faster. Make sure it is not turned in all the way.

                        Second put the lever in the down position (tractor does not need to be running) and see if you can get the arms to go down. They will usually fall under their own weight but standing on them speeds it up.

                        If you still can’t get the arms down, then about all that is left is to remove the seat and the top cover of the tank so you can have a look at the piston and piston rod to make sure things are OK in there.

                      • #49421
                        DavidPrivett
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                          as I reread your post if the lift works when the tractor is off I do not have a clue as the engine must be running to rotate the pump unless you would have a electric hydro pump somewhere , I really doubt. now the arms could go down with no power but not up.

                        • #49422
                          Topgun. 53
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                            • If your arms are already up they can’t go any further. I had a problem on my 2425 where the arms wouldn’t go back down. Under the front of the seat there is a funny looking half moon knob… turn that counter clockwise till the arms drop. It determines how fast the lift arms drop. If that is turned too far down they won’t drop.
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