Repairing MF35 Utility Hydraulics

[shaeff]

Finally got to work on the tractor again, only for a bit. Rechecked the stand pipe, it is properly seated. Still no working rear hydraulics.

I'm going to download the hinge/bracket .pdf from VTE and hinge the top cover plate back off, recheck the adjustments on the control and draft levers, if that doesn't work, pull the pump and spin it with a drill to verify it's actually pumping.

Edit: if I pull the hydraulic transfer plate off the stand pipe and put my finger on the pipe, it feels like it's got VACUUM. No fluid is being pumped into the stand pipe at all. Pump issue?

Thoughts?

 

[trustbase]

hi
I would check the filter on the pump to see if its blocking the flow and I hope the control valve is installed in right direction.if its reversed the output will be affected.Even though the relief vavle is new I might check on it if its struck in open and letting all the oil to drain back in casing.
Hope its as simple as filter blockage.
I am trying to get updated on your project by going over all you posts.hope this helps.

 

[shaeff]

Hey, thanks for the reply! I put a brand new filter in, but I'll definitely check to be sure it's not obstructed in any way. I followed both the factory repair manual and the Vintage Tractor Engineer video when I was rebuilding the pump, so I'm reasonably sure that I did it correctly and that the control valve is assembled properly. If it comes down to it, I can have the pump back out in about a half hour once I fabricate the bracket/hinge for flipping the top cover. We'll get to the bottom of it, I'm pretty excited, I mow about 1.75 acres now with a riding mower, but we own 4.5, so I'll be able to keep it all down once I get this fixed.

In the meantime, I checked the power steering reservoir and changed the filter. It was empty, so that explains why the power steering didn't work. Now I can turn the wheel with one finger. All that's left is to figure out this 3pt lift and the tractor will be put to use for the first time in years!

 

[shaeff]

Well, I ended up pulling the top (heavy!) cover plate off completely. It was raining here and I wasn't running my welder and plasma cutter in the rain. I'm sure it wouldn't end well.

I fired up the tractor with the cover removed and a piece of wire around the control lever's top roller. Even when I pulled it all the way, nothing came out the stand pipe hole in the top of the pump. It did, however make an empty/hollow gurgling sound similar to a draining washing machine. (Weird?)

Suffice to say, it seems to be an issue with the pump it itself so I removed it again to disassemble and inspect it to see if I did anything incorrectly. I'm going to pay very close attention to the control valve.

Edit- I also ran it with the hydraulic filter screen removed, no change in behavior.

 

[shaeff]

Heh, anyone have a dunce cap I can borrow for a bit? I walked down in my basement and looked at the pump for the first time with a clear mind. I've had a string of bad luck since December so even when I "relax" and work on the tractor, I still have a million things racing through my mind.

The moment I took the pump out of the bag I realized... I installed the cylinders upside down. Ugh. If you look back at previous pics I posted, it's pretty obvious that it just doesn't look "right."

Oh well, live and learn. Going to grab new o-rings for it as a number of them look distorted, probably from hydraulic fluid being pumped past them. Maybe soon I'll finally get this thing done!

 

[shaeff]

I got all my o-rings replaced again, some were blown out from my aforementioned folly. I reassembled the pump CORRECTLY this time, finally got a chance to drop it back in the tractor yesterday.

I connected a string to the control valve, popped the stand pipe in place with a hose connected to route the fluid flow back into the case, fired up the tractor with the top cover off.

Give the string a pull and voila! Pumping hydraulic fluid! Success! So I took the opportunity to put the top cover back on, torqued it down and began adjusting the nut for the hydraulic control lever. I spun it in and sure enough, the three point lift arms came right up!

My father used to have an older International 65hp diesel, and has some parts left over. One of those parts is the threaded upper link which I found today. Had to grab a bushing to drop it from cat2 to cat1 from tractor supply.

So hopefully tomorrow I'll put the grader box (about 450lbs) on it and set the control valve nut once and for all, put the dipstick plate back on, then it'll be small things to button up and it's done.

Not sure if anyone is really following anymore but hopefully this helps out someone in the future.

 

[cglaser104]

That's great! I'm glad to see you have it working! Good luck putting her through her paces!

 

[shaeff]

Thanks! All said, I've got $1,980 into this machine. I don't think that's bad at all for a good 35 utility with a loader! I'm looking forward to having it 100% done!

 

[shaeff]

So, I jacked it up today to replace the air/water valve stem in the rear left tire, old one leaked and disintegrated upon touching it. :/ and of course while it was in place it looked like my new one. Once removed, I noticed the new style A) doesn't fit, B) if it did, the threads on it are male and I need female threads. Hopefully I'll be able to find a replacement locally.

Also, while the transmission may not be leaking into the bellhousing, it seems as if my leak is from the rear main seal. I'll run it a bit, but will likely split it next year. In the meantime I'll keep a vigilant eye on the oil level.

 

[PatrickS2222]

Good to see its 3PT lifting! :thumbsup: Fix that tyre and you're in business. You've got a good machine for that money. :drink: