Hi John, from archives from Bernard le mécano Québec Canada,
3 pt will not go down:
There is a cover on the right side, in front of the rock-shaft. Remove and check if the spool valve moves with the position lever. Make sure the draft lever is down. There is a long spring, with a rod, maybe the spring is unhooked.
Maybe the unload valve is stuck. Check with engine running, raise the hitch and pull at the same time the remote lever. If the hitch raises, you have dirt in the unload valve. This valve is under the seat and you remove the large plug for access. One trick, loosen the large plug, and the unload valve, 2 turns and start the engine, the hitch should raise if the valve is stuck. It has a small hole in the valve and just blow the dirt out with air. Replace the O rings.
Hope this helps