Tractor Repair: Ford 5200, latly, check valve


Question
I have a Ford 5200 (~1972 year model).  When I start the tractor, the 3 point lift raises to the full upright position.  This happens, then is OK for a while, then happens again.  Nothing that I have tried makes it happen or not happen.  What do I need to do to fix this?

Answer
Hi Russel.
Have you done any work on the tractor latly ,that may have affected the hydraulics--- oil change ? is the level ok
Other wise this indicates:-
worn or damaged check valve
unload valve plug worn.
faulty lift piston seals
cracked or porous lift cylinder ,or lift cover castings.
but check with your manual which can be obtained through .
www search!

Martin