MF165 lift cylinder problems, pressure relief problems

Ok, I bought a Massey Ferguson 165 recently. When I bought it, the lift arms would raise as soon as the tractor was started. But you could push the arms back down, by hand with little effort. Then as soon as you let go of the lift arms, they would go right back up. It did not matter what position the draft control or the position control levers were in.

So I removed the lift cover and found the lift cylinder was split wide open, so I ordered another one. I also picked up a manual for Massey Ferguson tractors, not specific to the MF165. But it has useful info, but lacking info and pictures.

I adjusted the internal linkage according to the manual, also checked the master control plunger spring adjustment. Some of the linkage adjustments seemed to be off, the master control spring seemed to be adjusted correctly.
I replaced the lift cylinder, lift piston rings, o-ring between the lift cover and lift cylinder, stand pipe O-rings, then made the adjustments to the internal linkage. Some thing I noticed right off, was the control lever has two adjusting screws on the lower end of the control lever. Most of the pictures in the manual I have, that show the lower end of the control lever, only show one adjusting screw on the lower end of the control lever. I figured out that lower screw, is a adjustment for the pressure control lever, it rides on the roller, that is attached to the pressure control lever.

I did find one picture of a control lever that had two adjusting screws like mine has. In that picture, there is what is listed as a pressure control diaphragm or control diaphragm. That diaphragm has a plunger that makes contact with the upper screw on the lower part of the control lever. My tractor does not have one of those control diaphragms, the bracket has the holes for that part, but it's not there. If it had a control diaphragm, it would be bolted to the bracket, that bolts to the lift cylinder. The same bracket that the draft response dashpot bolts to. There are other holes in the same bracket, that look like they had something attached using those holes at one point in time.

I am curious if anyone on here has decent experience with MF 165s and preferably the multiple variations of hydraulic systems used in them. I have read they used multiple systems for the lift cylinder and for auxiliary lift pumps for remotes. The manual I have does not go into much detail, on what all components are used with the different systems and how they work. Basically at this point, I am not sure I have a functioning pressure relief valve in the tractor or a properly functioning valve or if all of the components for the pressure control are there.

Also looking up the VIN number, it seems to be a 1974 model tractor. The lift cylinder I have, has the 3 3/8" bore diameter.

Thanks for any info.

Some tractors had a pressure control feature, and that was used for the relief system. Your pump has a relief valve on it so I doubt you have the pressure control option. I'd remove the valve you have and have it checked, it may be stuck shut.

Hey. I just recently had my top cover open on my 165 multi power.
I am by no means an expert but it is fairly fresh in my mind.
Hit me on email ([email protected]) or find me on Facebook. Instead of steve, use Stephen.

I have some of my own pics
And can take pics of a good service manual.

Did you remove the roller before you removed the top cover, or was it already missing (see red circled area on the lever in the picture).