2017 Kioti CK3510HST 3 point dropping issue

[MYoung]

My 3 point hitch oscillates up and down in short rapid successions (much like the repetitive motion of dribbling a ball close to the floor). The higher it is lifted the worse the motion. Also, when I raise the 3pt to max height, turn the MLS knob so it locks the 3 pt in place, move the 3 pt lever to the lower position and shut down the tractor, it drifts to the bottom.

I have replaced the MLS valve, I have replaced the pressure relief valve and has been set per manual. There appears to be air bubbles in the system which from what I understand, indicates the system is not working properly.

Is there anyone out there that has had this issue and found a remedy for it?

 

[ptsg]

Your first sentence pretty much confirms bad piston seals on the 3 pt cylinder.

The 3 pt hitch valve is doing what's suppose to do, which is keeping the position set by the lever. As the 3 pt drifts down, it commands more oil to raise it back to the preset position.

Since the 3 pt is dropping even with the flow control valve (that knob below the seat) all the way closed, it means it's leaking past the seals. This is actually the procedure used to verify bad seals.

 

[MYoung]

Thank you!