Three point linkage arms raising and lowering w/o lever

[p laurence]

Hello, I have a 1975 MF 135 3 cyl perkins. If I move the HYD lever slightly up, the three point linkage arms will go full height and same if moving slightly down, it will go full down. I noticed several days ago it will lift on its own with a load on or empty and am unsure why it would be doing this. Moving the draft lever makes no difference at all to the situation.
Any help would be greatly appreciated!!!

 

[alltron]

I don't see anyone answering your query. The first thing I wonder is what about Draft Control Lever. Are you familiar with the Draft Control, and does it make a difference where you set it? The other thing, has someone worked on the system since you've started to have this issue? The two levers indirectly move a hyraulic valve at the heart of your lift system, so something is allowing oil to continue to pass thru this valve. More than likely the position control mechanism is not being allowed to return to the 'neutral position', for whatever reason. Good luck.