3 point will not stay lifted

[blupen]

I have a problem with my JD 4052R. It started while I was running the disc on one of the fields. I attached a video. I tore off the side plate with the valve bolted to it and took the valve off, cleaned it and installed new o-rings. I also changed the filter. I put everything back together and it still leaks down. I found if I turn the knob below the seat that controls the rate of decent all the way in it nearly stops the drop. If I set the knob where it usually is (1 1/2 turns out) it acts like the video attached. Any help?


It won?t let me add the video, probably doing something wrong. When I lift the disc it raises to position, then drops several inches and raises again to the position, drops, repeat. Each cycle takes only seconds.

 

[ptsg]

Seems like the classic issue of the bad piston seals, specially after you mentioned that even with the drop rate knob closed, it still leaks down.

Piston seals go bad on the lift cylinder. Then the position control valve, tries to compensate for the drop rate and maintain the set position on the lever, basically doing its job. And it just keeps bouncing up and down.

 

[blupen]

Can you tell me what is involved in fixing this? Thanks!

 

[ptsg]

Here is the link for the JD parts catalog. Hopefully it'll detect your country and won't show everything in Portuguese like me.

John Deere Parts Catalog

The piston is the number 5. Then you have all the seals with number 6, 7 and 8.

Taking the part 15 housing lets you see the piston. I think you should be able to pull it how, but I can't confirm as I don't know your tractor.

 

[blupen]

Thanks! This helps. Only problem is I have a cab so I値l have to look it over to see if I can get to it without removing the cab

 

[WranglerX]

I eliminated leak down drop to lowest limit I wanted by using check or stay chains.... Got tired of ballast weigh dragging on ground if I ignored the 3PH height....

Dale