John deere 750 3 point hitch

[Ky farmer16]

Hey yall I just bought a john deere 750 tractor 4 wheel drive and I'm having an issue with the raising of the 3 point hitch I can raise it up fine but if I try to haul a trailor or anything with it it's weak and goes down unless I have it up all the way I've looked everywhere for options and don't know how to fix it....I can't just leave it halfway up it vibrates sooo much it just falls all the way down so I figured maybe one of yall had a fix for it thanks in avance

 

[California]

If you don't get answers here, re-post over in the Classic Yanmars subforum. Yanmar built that 750 for Deere, and its 3-point is likely the same as several Yanmars of that era.

 

[rScotty]

If you raise the 3pt up and then close the needle valve knob under the front of the seat it shouldn't move. If it still goes down, you may need to renew the seal in the 3pt piston. The workshop manual describes how to do that.

 

[Ky farmer16]

I raised the 3 point up all the way and adjusted the knob and it don't go up or down then I found a lever under the seat on the right side of the tractor if ur looking at it from the back and fiddled with it and it's still doing the same thing so idk hopefully I can get it fixed before we try to plow the garden

 

[rScotty]

I raised the 3 point up all the way and adjusted the knob and it don't go up or down then I found a lever under the seat on the right side of the tractor if ur looking at it from the back and fiddled with it and it's still doing the same thing so idk hopefully I can get it fixed before we try to plow the garden

I have no idea what that lever is. If it didn't do anything then it's best put it back where it was. And open up that needle valve under the front of the seat a half to a full turn. Then the arms will go down.

From the sounds of things, the seal on the 3pt piston needs a new O ring. My guess is the old O ring is leaking past the piston.
Replacing it is not a big job, about a weekend and the parts are just some O rings and gaskets... but the first time could be a little confusing because the insides of a 3pt hydraulic aren't like anything else in the world.
Have you got a good mechanic there? Either that, or get the shop and parts manuals and see what's involved. Whoever does it will need those manuals anyway to put the adjustments right.
luck,
rScotty