to-20 lost 3 point control

lost control of the lower control of my 3pt, had JD manure spreader (pto driven flinger, ground driven conveyor) hooked up to the crossbar between the lowering arms and the pto connected, everything was going fine then all the sudden i heard interfierence from the crossbar raising up into the pto shaft to the JD, I disengaged the pto and attempted to lower the 3pt,(control lever was in the bottom of the lower position). would not respond with the control lever, I could stand on the lowering arms and they would drop, started the tractor again and the lever was in the lower position but the arms began to raise again, any one know what i gotta do?

It spounds like the control valve is sticking. Pull the side plate and check it out.

First of all, it is not advisable to use the 3 point like this to tow anything, you should not be carrying any trailed implement on the hydraulics as it can be unpredictable because it is a Draft only system and does not control for doing this type of work, it needs some pressure from the implement down the top Link to be able to function. You should really use the draw-bar fixed with the adjustable stays,it is much safer and less likely to give you any problems.(see picture)
If you are getting no response from the movement of the Control Lever it is almost certainly that the Control Valve has stuck or become detached from the Fork.If you remove the right side round plate on the side below the seat position. You will see the legs of the Control Fork Hanging down from the top. If you place the Lever in the lift position, make sure that the Pump is running, then using a long screwdriver or something similar, gently try to move the Control Fork back-wards and for-wards GENTLY, don't force it. If it is successful the movement will cause the 3 point to raise and lower, if it doesn't move then it is possible that the Control Valve has become detached from the Fork. If you need more information about this and what you should do next, email me at the address below and tell me what happened when you tried all this and I will send whatever you need...John(UK)[email protected]