Near catastrophic 3 point hydraulic nightmare.. Massey

[greymond]

I am finally getting this little Massey Ferguson M35 diesel tractor up and running. The 3 point system on it wasn't working properly when I got it. The previous owner told me it would only go up about 6 inches and slowly at that. He had a guy put in a new cylinder and piston a few years back but said it still wasn't working correctly and the tractor sat not running since.
I installed a gauge on the cover to check the pump pressure. I engaged the lift lever and the pressure shot all the way around the dial and pinned back at zero. Then one of the studs on the cylinder flew out of the top of the cover and across my shop. I shut everything down and pulled it all apart. Below are a few photos. I have no idea what happened to the piston. The cylinder was pushed away from the bottom of the cover and 2 of the 4 studs were broken off. It looks as though there was no releases of fluid and it just built up until it pushed the cylinder. I suspect the safety relief valve is shot. But I dont know what exactly is going on here. The original cylinder is in the photo below the one with the huge crack in it. The PO installed a new cyclinder at some point. I sent a magnate through the case and I only found the debris from the cylinder damage. It doesnt look like anything else is broke. I did check the pump pressure via the tube at the top and fluid is coming out when engaged so it looks like the pump is working. I am thinking the safety relief valve failed but I don't have a lot of expiernece with those and what happens when they fail. Anyone have any idea what went wrong?

 

[Phill Tibbetts]

Years ago I broke the studs and ruined the cylinder by mistakenly putting the lever in the constant pumping position with the engine at nearly full throttle and no place for the oil to go. Perhaps that is what happened.??????

 

[greymond]

(quoted from post at 00:18:03 10/15/21) Years ago I broke the studs and ruined the cylinder by mistakenly putting the lever in the constant pumping position with the engine at nearly full throttle and no place for the oil to go. Perhaps that is what happened.??????

Could very well be. My mistake was not taking off the side cover and looking in to see if anything looked out of wack. Better yet I should have pulled the whole thing off. Ive got to get a detailed diagram of whats going on with the inside of this thing.

 

[Phill Tibbetts]

If the cover is not damaged a new cylinder and piston may be all you need. There is a lot of pressure when in the constant pumping position.

 

[greymond]

(quoted from post at 00:18:03 10/15/21) Years ago I broke the studs and ruined the cylinder by mistakenly putting the lever in the constant pumping position with the engine at nearly full throttle and no place for the oil to go. Perhaps that is what happened.??????

What position is the lever when it is in "constant pumping position"?

I am trying to get my head around how this system works. The book I have doesnt show a good photo of how the levers should be. I looked at a few references I found on the web and the below photos is what I came up with. I mocked up the cylinder and the levers to get a reference. I have NOT made the final adjustments just yet. I need to get a couple replacement studs for the cylinder. Can you recall if this looks correct?
thanks

This post was edited by greymond on 10/17/2021 at 06:47 am.

 

[Phill Tibbetts]

The lever next to the seat would be in the full up position when in constant pumping. There should be a stop there to keep it from going all the way back unless somebody has removed it. I'll try to get some pics of my 135 which is the same.

 

[Dieseltech]

I'll bet the relief valve is stuck closed, it SHOULD open when needed to protect the system, EVEN in constant pumping for auxiliary valve work. Tractor lift covers and
the diff case have been known to break too when the valve is stuck closed.

 

[greymond]

Thanks for the help with this!
The previous owner really struggled with the hydraulics on this tractor. He wasn't a mechanic and didn't wrench all too often and finding a mobile mechanic around here is near impossible. Ultimately I believe the hydraulic issue why I ended up with this tractor. Most everything else is in great shape.

 

[John Deere D]

Pic off YT

Possibly end result from Faulty Relief Valve

Bob..

 

[greymond]

saw that.. thats terrible. Mine was similar but not quite as bad. I am surprised more damage didnt occur on mine.
Iv'e since learned the PO changed the piston and cylinder and rings and DID NOT swap out the relief valve. The original piston was cracked probably from the same initial problem (relief valve). Then he had the new cylinder put in and parked the tractor and never used it since. I got it and BOOM! Much as I can gather what happened.

This post was edited by greymond on 10/15/2021 at 08:34 am.

 

[Phill Tibbetts]

First 2 pics are my 135, next 2 are my TO35. You can see the stop in both is set to prevent constant pumping.

 

[greymond]

Update on the hydraulics! working like a champ now! I ended up replacing the cylinder pump, piston, rings, safety relief valve, filter, studs and fluid.Made the proper lever adjustments per the book and I put a gauge on it and it topped out at 2800psi. I reset the adjusting nut and bolt to 1/2" below full rise in order to shut of constant pumping. Working great now! Thanks to everyone for the help and insight. Ironic right when I get it all operating correctly the rain comes and the forecast is 14 days straight rain. It looks like I won't get an implement on it for a while.

This post was edited by greymond on 11/01/2021 at 09:11 am.