Shibaura SD 1843 / 3-point hitch dropping

[timschafer]

My 3-point hitch is slowly dropping with control in open position. It goes up fine. It drops fine. When you let go of joystick it slowly drops depending on how much weight you have on. Throttle makes no difference. If I turn adjuster all the way in or out it makes no difference. I have a parts manual, working on getting a service manual. If anyone can tell me where I should start. I'm not a diesel tech., but I'm fairly good fixing things.
Thanks Tim

 

[Fawken]

Probably the parachute seal in the lift cylinder. Not a hard fix if you can find the part.

 

[timschafer]

Thanks alot for the help. I'll go there next. Is it possible to just be the o-ring?

 

[Fawken]

When you close the flow regulator all the way, you are isolating the circuit from the position control/pressure relief valve. There is an O-ring in the flow control valve, but you won't see it without removing the valve which is the first step to getting into the lift cylinder. This advice is assuming your Shibaura is laid out similarly to mine. Here's some pics:

 

[timschafer]

Looks the same. Thanks again.