3-Point Hitch Massey Ferguson 135 Restoration Project

[bmacd11]

Hello everyone, my name is Bill. I've been working on a 1967 MF 135, with the constant pumping feature, that I bought last summer. To put it mildly, it is a fixer upper, or more like a basket case actually, but I needed a hobby. This is the second MF 135 that I've worked on. My brother had one which was also a basket case and we basically rebuilt it. That was a great experience and I learned a lot.
Back to mine now; I took the lift cover off and went through all the adjustments since the hydraulics were kind of squirrelly when I bought it. The lift arms dropped as soon as the tractor was shutdown and the 3 pt controls were way out of whack. The hydraulic fluid was mostly water which I thought was a big part of the problem. I replaced the lift piston for one with the teflon ring over an O ring. I made adjustments using the MF shop manual; of course, I had to improvise on the special tools. The 3 pt works much better except for some very minor chatter while raising. It was more noticeable before I changed the oil but next time I have the lift cover off, I'll change the valves too. The new lift piston works much better and holds the load up after shutdown but it still falls over time (about an hour with a load on it). The cylinder walls were pretty scored up so I expect that is the problem. I did hone it a bit before re-installing but was afraid go too far with it so there were still noticeable scratches on the side walls when I put it back together. I have a new cylinder on order now.
So, now to my question: when I start the tractor with the position control fully down and the draft control fully up, the lift arms raise slightly to the level position. I don't think this is correct since someone could get hurt like this. The only way to stop this from happening is to start with the draft control fully down. Even then, when I raise the draft control lever to give me access to the position control function, the arms raise to level. Any ideas on where I went wrong on the adjustments? I expect the issue is the draft control adjustments but I don't really know why. The tension on the vertical lever was 6 pounds and I changed it to 3 pounds as per the manual. I don't know if I should put more tension or less on the draft adjustment. The manuals are good for telling you what to do but not for when something weird happens like this. One other point is that I really couldn't get 3 pounds on the position control set-up as called for. The adjusting screw is all the way in and there's maybe 2 pounds on the vertical lever; something wrong with the position lever that would cause the issue? Having said that, the position control lever works perfectly when running.
Appreciate your thoughts on my issue. Thanks in advance.

 

[joh]

Hi Bill, so i used to have a 1963 Mf 35. I don't know what the differences between the 135 and the 35 are, however I believe some things might be the same. Using the position control on mine meant the draft control was all the way down. One would use the position control to lift to carry it and then to lower the ( bellow ground engaging) implement to where you wanted to use it, then while proceeding forward, I would move the draft control until I got it to the depth I wanted! A new lift cylinder and piston have to be pretty tight not to loose pressure when the engine is not running. I bought two different pistons and two different cylinders. Both pistons were exactly the same diameter, however the lift cylinder were quite different, even thought both were new! I could see hydraulic fluid dripping out of the cylinder when the engine was turned off. On my tractor, where one checks the hydraulic fluid level, there's a cover plate that you remove to see where the draft and position control levers (also where I detected the leaking lift cylinder), when in their neutral positions, should be just touching, a lever on the hydraulic pump. While the tractor is running, even if your lift cylinder is leaking, the hydraulic pump should still maintain the lift arms set position. Hope this is useful! I'm trying to find my old manual to check my facts!

 

[joh]

I neglected to give you the head up, about lowering the hydraulic fluid level before you remove the side cover. I usually take out half the volume, remove the side cover then fill it back up till it is just about to flow out of the opening. For my tractor, that level is enough to cover the pump intake.* Let the pump run for a bit, raise the lift arm enough with the available fluid ( you always want the pump intake to be submerged), then turn it off and wait to see if the lift cylinder shows signs of leaking!

 

[bmacd11]

I removed the lift cover again and re-did all the adjustments. Both draft and position adjustments were out very slightly. Put the cover back on and the same thing happened; with PC down, I raise the draft control all the way up. This causes the lift arms to raise 1&1/4 inch which translates to about 4 inches at the lower links. Is it possible that this is normal? Doesn't seem right to me but all internal adjustments are correct.

 

[joh]

I removed the lift cover again and re-did all the adjustments. Both draft and position adjustments were out very slightly. Put the cover back on and the same thing happened; with PC down, I raise the draft control all the way up. This causes the lift arms to raise 1&1/4 inch which translates to about 4 inches at the lower links. Is it possible that this is normal? Doesn't seem right to me but all internal adjustments are correct.

I don't have my MF35 anymore and it's not clear to me, what my tractor did when set-up with the PC down and the Draft control all the way up. I don't have any manuals that talk about what should happen in that situation. However, I do know, when using a plow, my draft control functioned well, allowing me to control it's depth, and I do remember that not having anything attached to the lift arms, with the PC down, the draft control lever full range of movement, didn't result in the same kind of change as the PC (with the draft control all the way down). I just don't remember how much of a change resulted.

 

[bmacd11]

Thnaks for looking Joh. On my 67 MF 135 (and my brother's 73), the draft control has to be all the way up in order for the Position Control lever function at all.

 

[bmacd11]

A revelation: while still investigating, I removed the position control lever slide tensioner and moved the PC lever all the way down, and past the stop (about 3/4 inches further that the PC lever channel would normally allow). The lift arms dropped to the full down position. The lift arms now raise and lower through their full range and specifically go all the way down when I go past the tensioner channel. With the lift cover off and still upright, you can see the lift cam moving downward another 1/8 inch when going past the tensioner channel and past the stop. Same thing with the lift cover upside down except that the lift cam moves upward relatively. So, I believe that the lift cam is not moving to its full down travel when the PC lever tensioner and stop are in their normal position. I've tried to adjust everything to make the lift cam move that extra 1/8 inch with the PC lever in its normal physical travel channel to no avail. So, what is the issue with the position cam travel? Could it be that the cam or its rollers are worn to the point where it can't get that extra 1/8 inch which in turn won't let the lift arms fall all the way down? The tractor does have a lot of hours on it.

 

[joh]

If the cam was worn down, I would think that you would see a groove worn into the cam (since the cam is wider than the lever pressing against it). My unit had 4000 hours without any sign of wear. Does the cam and rollers move smoothly? I'm presuming you loosened the nut securing the cam so it's positioned properly against the lever, it can move out of it's adjusted position, if you overtighten the nut. Any chance, there's a slight difference between your old and new lift cylinder, such that the attached lever assembly, changes how the levers interact with, the roller on the pump control lever. The levers would exaggerate the difference. My levers were bent out of shape (from hitting the lift cover opening, when re-installing the lift cover) and a bit sloppy, I was not able to replace the assembly, just played with bending them until they worked as they should (don't want them rubbing each other)!

 

[bmacd11]

A solution?? I was researching the issue on the internet last night and came across a technical article by Agriline Diesel in South Africa. Massey Ferguson | MK2 Hydraulic System | Maintenance
They run a tractor shop and specialize in Massey Ferguson and Ford. They say in the article that due to wear over the years, things will have to be adjusted to reduce stress on the hydraulic system. One of the adjustments suggested was to move the adjustable inner quadrant plate (position plate) toward the rear of the tractor. This adjustment was meant for setting lift arm free play at the top, but I thought why wouldn't it work to adjust the bottom setting as well. Well, I did that today and wow; problem solved. When I start the tractor with draft control up and PC down, the lift arms don't move. The lift arms respond to PC inputs through the entire range and stop about 1/4 inch from the top (measured at the ram shaft).
I think this is a great solution to my problem specifically and may be helpful for others out there.

 

[GeorgiaRebel]

Nice detective work to find a solution.