Repairing MF35 Utility Hydraulics

[shaeff]

1) Starting to fit the cylinders, you have to have the cam rotated JUST right in order to get it all in place, carefully pinching the piston rings to get them to fit into the cylinders. Stagger them so you can fit one full side at a time.
2)Doing the same to the other side
3) Had to flip it over, pic is blurry, sorry!
4) Both cylinders fitted. This is a bit of a fiddly job
5) same
6) put the front suction plate back on

 

[shaeff]

I had to refit the control valve as mentioned earlier, here's the back side of it, the oscillator assembly. It has a large circular hole in one end that attaches to one of the cam blocks, and the other end attaches to the oscillator assembly, It's primary function, from what I understand, is to prevent the control valve from ever sticking by constantly rocking it back and forth as the cam rotates. The spring was blown out of mine, rusted in half, and the the circlip and end cap were gone. The end cap piece that helps hold the spring is NLA according to my dealer, so I used a washer that fit very snugly. On to the pics:

1) Where the control valve spring goes, in the oscillator assembly
2) The brand new control valve spring. It's a bit finicky to get it in place, but not terribly difficult. Having your hands covered in hydraulic oil certainly doesn't help!
3)All fitted. Behind the spring is a small rod that fits into the control valve, which is how the control valve gets it's spring tension
4) Here you can see the control valve rod pressing perfectly against it's roller. Success!

 

[shaeff]

Now that the pump is done and ready to go back in, I turned my attention elsewhere. I had to replace the o-ring on the PTO housing and the PTO seal as well. Note: the 50yr old seal is MUCH better quality than the one I got from the dealer. It's got a metal housing, which makes it abundantly easier to press into place. I made the new one work, but it wasn't as easy as the old one probably was. I ended up using the original steel cased seal to help press the new one in place.

1) grab some large sockets and chuck it up in the vice. One to fit the diameter of the seal, one of the seal housing
2) turn carefully until it pops out until you have just the housing, now's a great time to clean out the threads! (no pto shaft in your way!)
3)old seal
4)same
5)cleaned out the threads of the PTO housing
6) old seal vs new
7) again

 

[shaeff]

Last update for the day as I don't have pics of the rest yet:

The original lift cylinder on my Massey 35 Utility was threaded for 1/2" studs. They're small, they broke, which is the whole reason I was able to get the tractor so cheap (no 3pt lift and it didn't run), looks to me like someone lifted something too heavy and bounced it on a bump. I can see on the axle housing where the 3pt lift arms contacted the axle. Big dent in the steel. So when I pulled it apart and the lift cylinder wasn't even attached to the top cover plate, I knew I needed to dig it all out and repair. The new lift cylinder I bought is drilled for 9/16" studs, much sturdier. They're only 1/16" of an inch larger, but they LOOK huge in comparison! I'll get a 1/2" vs 9/16" comparison shot next time I get to work on the machine. In any case, I had to drill out the top hydraulic cover plate on which the cylinder is mounted for the larger studs to fit. Pretty easy with a good drill bit, now I may need to just ream the holes a touch for an easier fit. Pics of that to follow:

1) finished up the hydraulic pump and reinstalled, this pic before I put the drive shaft and sheer collar back in.
2) Drilling the cover plate
3) same
4) same
5) same
6) last but not least, new hydraulic lift cylinder, fitted with new 9/16" studs. I still have to install the piston/rings.

I also degreased the inside of the cover plate (pic1) and hosed it all out. Much cleaner now. I removed the control levers as well because they're pretty rusty and the levers don't slide on their slides smoothly, although everything inside is free. More updates to follow, but probably not for a week!

For those of you just tuning in, thanks for reading. If anyone's got any suggestions, feel free to let me know! Also, depending on how many posts per page you've got the forum set to, there are new pics on the last page as well! Enjoy!

 

[shaeff]

Alright, fellas. I've hit a bump in the road again. Need some help. I rebuilt the hydraulic pump, reinstalled, new o-rings and gaskets everywhere, filled with 5gal of hydraulic oil and fired up the tractor. (only five gallons so I can keep one of the side plates off to see inside) I've made all my adjustments to the hydraulic control levers (position and draft) as well as the final adjustment to the lock-nut on the control valve. When I fire up the tractor, I see fluid swirling around inside the case as if the pump is operating, but still no 3pt lift.

After all of this, I hate to admit it, but I'm frustrated. I was sure hoping that I'd fire it up and the three point hitch would magically work again. Tomorrow if it's not raining, I plan to pull the stand pipe to see if the pump is actually working. I wish I had someone in my area that knows more about these tractors than I do.

When I try to operate the control valve with a screwdriver, it feels very tight while the tractor is running. However, when I turn the machine off the valve moves a bit more freely. I'm fairly certain I did the adjustments correctly, as I followed the Vintage Tractor Engineer DVD.

So, any advice for me?

 

[banjodunn]

G'day I would say the standpipe is not in correctly

Jon

 

[shaeff]

G'day I would say the standpipe is not in correctly

Jon

Hey Jon, I'll pull it back out once it stops raining here, been raining non stop since last night! Hopefully it's something simple like that! Thanks for the suggestion.

-Chris

 

[cglaser104]

Hey Jon, I'll pull it back out once it stops raining here, been raining non stop since last night! Hopefully it's something simple like that! Thanks for the suggestion.

-Chris

Any luck on this?

 

[shaeff]

Not yet, I haven't had a chance to get back to the tractor, life keeps getting in the way! Hopefully I'll get to poke around on it a bit this weekend.

 

[PatrickS2222]

Sorry ... wasn't following lately due to no email alerts until June 6th, which I finally saw today :ashamed:
First thing I thought of was the standpipe as well, but your comment that the control valve seems tighter when the engine is runnung (pump is driven) so one reasonably suspects there is restriction to the pump output. That said, I would certainly check it anyway before doing anything else.
I'm not much help beyond that - so long since I've worked on one!
Remember ... sometimes Google is your best friend!!! :laughing: