Repairing MF35 Utility Hydraulics

[PatrickS2222]

It's called technology - Computers are supposed to make life easier!

Don't stress - PTO shaft is brutally strong, but circlip in front of bearing may let go - this will help!
A soaking for several days with penetrating oil will assist..
*** Remember: Bearing holder (round, but with two flats) is held in housing by three bolts through retaining plate and is sealed by a thick O-ring.
Bearing, seal and O-ring are very cheap to buy (here at least). Bearing is also quite robust and will stand up to some force.
A slide hammer is the best tool, to connect it maybe sacrifice a D-shackle just larger than the shaft diameter, and a strong bolt through the hole with a nut to close it against the shaft.
Best of Luck! :thumbsup:

 

[shaeff]

It's called technology - Computers are supposed to make life easier!

Don't stress - PTO shaft is brutally strong, but circlip in front of bearing may let go - this will help!
A soaking for several days with penetrating oil will assist..
*** Remember: Bearing holder (round, but with two flats) is held in housing by three bolts through retaining plate and is sealed by a thick O-ring.
Bearing, seal and O-ring are very cheap to buy (here at least). Bearing is also quite robust and will stand up to some force.
A slide hammer is the best tool, to connect it maybe sacrifice a D-shackle just larger than the shaft diameter, and a strong bolt through the hole with a nut to close it against the shaft.
Best of Luck! :thumbsup:

Right on!

I've got the inner seal and outer o-ring on my parts list for the bearing holder. Definitely replacing those. I'll swing by the hardware store and see if I can find a suitable D-shackle. That's a pretty good idea!

 

[PatrickS2222]

Yep, start by spraying the area again regularly with penetrating fluid, then grab a couple of shackles, beefy-looking ones - as close to the shaft diameter as you can find. You will need a 1/4" bolt & nut through it and the shaft, strong enough so as to not shear under stress. Pull it just tight enough to close the shackle onto the shaft, but any further tension will only be counter-productive. Add a serious-calibre slide-hammer with an eye on the end. Be aware the shackle or the bolt may break, you may also quickly succeed instead! :thumbsup:
I can't remember the specific shape of the shaft inside of the casing, but you may pop the circlip off and get only the shaft out. Then you'll need to get inventive to engage the slide-hammer in the bearing - I suggest a short but stout piece of round bar through the slide-hammer eye and across the inner edge of the bearing (you might need long-nose pliers, a magnet, an assistant, or all three) If if comes to this, I would feel more comfortable renewing both the bearing and the circlip.
As my father used to frequently repeat: On reassembly (after cleaning off rust and scale etc), coat over-lapping surfaces and all screw threads & shanks with grease ..... think of the next poor guy removing them - it could easily be you!
Example: Our MF135's rear wheels were last off in 1981 for replacement rear tyres. I punctured one about three years ago - the first tractor tyre I have ever damaged. Just as I was jacking it up after letting the water out, repeatedly re-inflating it until it was almost empty, one of my friends happened to visit. He scoffed at me expecting a 1/2" drive pneumatic gun to undo anything. Imagine his surprise when it removed all 8 nuts holding the centre to the axle and all 6 bolts and nuts holding the rim to the centre! :laughing: That was possible only because the threads were greased ..... and no, they weren't loose at all! I have continued this habit over the years, and found how advantageous it is, especially around cooling system components and also in areas exposed to the elements.

 

[shaeff]

Yep, start by spraying the area again regularly with penetrating fluid, then grab a couple of shackles, beefy-looking ones - as close to the shaft diameter as you can find. You will need a 1/4" bolt & nut through it and the shaft, strong enough so as to not shear under stress. Pull it just tight enough to close the shackle onto the shaft, but any further tension will only be counter-productive. Add a serious-calibre slide-hammer with an eye on the end. Be aware the shackle or the bolt may break, you may also quickly succeed instead! :thumbsup:
I can't remember the specific shape of the shaft inside of the casing, but you may pop the circlip off and get only the shaft out. Then you'll need to get inventive to engage the slide-hammer in the bearing - I suggest a short but stout piece of round bar through the slide-hammer eye and across the inner edge of the bearing (you might need long-nose pliers, a magnet, an assistant, or all three) If if comes to this, I would feel more comfortable renewing both the bearing and the circlip.
As my father used to frequently repeat: On reassembly (after cleaning off rust and scale etc), coat over-lapping surfaces and all screw threads & shanks with grease ..... think of the next poor guy removing them - it could easily be you!
Example: Our MF135's rear wheels were last off in 1981 for replacement rear tyres. I punctured one about three years ago - the first tractor tyre I have ever damaged. Just as I was jacking it up after letting the water out, repeatedly re-inflating it until it was almost empty, one of my friends happened to visit. He scoffed at me expecting a 1/2" drive pneumatic gun to undo anything. Imagine his surprise when it removed all 8 nuts holding the centre to the axle and all 6 bolts and nuts holding the rim to the centre! :laughing: That was possible only because the threads were greased ..... and no, they weren't loose at all! I have continued this habit over the years, and found how advantageous it is, especially around cooling system components and also in areas exposed to the elements.

Well, I got it out. It's amazing, I had tried a 6' pry bar attached to a chain last week too. No luck with that. I shoved the bar into the ground and created a nice sturdy hole and let it rip. PTO shaft wouldn't budge. So I tried the D-ring method, but I couldn't get it tight enough and it kindof acted like the chain, it seemed to take up too much of the blow from the slide hammer. So I tried to think of ways to hook the slide directly to the PTO, or more solidly, anyway. Considering I'm working on it at my parent's house, it's not uncommon to see my father wandering around with the dog. He walked by and suggested the method that worked like a charm.

I found a piece of heavy angle iron, grabbed my plasma cutter and cut it down the middle. (I couldn't find anything else thick enough). Ground it down, welded it into a flat piece of steel. I traced the slide hammer end in marker, cut out the holes and bolted the universal end of the slide to the plate. On the back side, I bent up a piece of band iron into a U-shape, drilled two holes and welded it to the larger plate. I stuck a bolt through to hold it to the PTO shaft, gave two very solid hits with a 5lb slide hammer and the PTO shaft ended up in my lap. Excellent.

Now the hydraulic pump is out, sitting on my workbench in my basement. Sometime this week I'll start pulling it apart. I've attached a few pics to make it clearer what I did to get the shaft out.

Also, it seems that the control valve on my hydraulic pump is seized. The large spring I found in the bottom of the sump definitely came from the pump. The good news is that the pump still spins very freely. Hopefully getting the control valve unseized won't be too difficult. I'll take pics as I go.

Thanks for all the help, I'll be back with more updates soon!

 

[PatrickS2222]

Great news - you got it out! Love your work! :laughing: Persistence combined with ingenuity pays off! :thumbsup: I like your and your Dad's idea very much - obviously very effective too. I've never seen any stuck as tightly as that. What a mission! Now you can continue. I look forward to seeing your continued progress.

 

[shaeff]

Haha, thanks Patrick!

I've got the pump torn down, I just need to grab my snap ring pliers to get the valves out for inspection. It looks like work may have been done to it at one point, though I can't be sure. I found a piece of debris in the pump that might be the remnants of a broken piston ring. I find this odd because my pump is fitted with the filter, but I digress. There is a little marring of one of the brass journals, but I can't feel it with my fingernail so I'm not overly concerned about it. I forgot to take pics (my hands were very oily, so not a lot of pics) of the brass cam blocks. There is a little marring on them, too, but not on surfaces that make contact with anything else. It looks like debris fell on top of the pump and as it rotated, got crushed against the pump casting and pistons. I'm checking with my local Massey dealer today to see what he thinks, he used to work on these machines daily so I trust his opinion.

Also, of note- for anyone looking to rebuild their pump, the Vintage Tractor Engineer DVD is truly the way to go. It takes out all the guesswork and goes into great detail. I'm pretty certain I could have pulled this apart and put it back together, but they go into detail about what to look for, and all the adjustments you need to make to the control levers and draft spring to make your hydraulic system function as intended. I highly recommend it!

On to the pics, they're grainy because I was working in my basement. My hands were oily, so cut me some slack.

 

[PatrickS2222]

Great, you've surged forward now! Nothing really high-tech - just thoroughness and attention to detail.

 

[shaeff]

Yep, I had a concern about the brass cam blocks being slightly scored, even though the scoring isn't on a mating surface. Local Massey dealer says they're fine. Looks like a good cleaning, new 0-rings, control valve/spring assembly, and pressure relief valve and I'll be putting it back together. Very promising!

I'm VERY happy I pulled the pump out, despite that pesky seized PTO shaft. The control valve wasn't operable in it's condition. The c-clip and end piece are long gone, the spring was laying in the bottom of the case, and the control lever with the rollers was not connected to/touching any part of the valve. I'd have been quite upset if I put it all back together and it didn't work.

 

[PatrickS2222]

Yes, it would not have made sense not to have investigated the pump condition having already gone that far into diagnosing the problem.
It all sounds rather straightforward from here.

 

[shaeff]

Yes, it would not have made sense not to have investigated the pump condition having already gone that far into diagnosing the problem.
It all sounds rather straightforward from here.

My thoughts exactly. I ordered all the parts I need to put the hydraulic system all back together. A full rebuild kit for the pump only cost me $150, then I got all sorts of other assorted o-rings and stuff for the stand pipe, and for the top lift cover too. Hoping they'll all be here before the weekend after this coming weekend, then I can put the pump back together and drop it in.

I do have another question:

The four studs that hold the lift cylinder in place- are they special studs? I've read that they're just grade 5 studs, and I've also read that they're special hollow studs designed to sheer if the hitch is overloaded. The guy at the Massey dealer told me that they're just grade 5 studs. That being said, when he looked up the price, they're $27/EACH! If they're just grade 5, I'll see if I can source my own. If they're special hollow studs, I'll order factory studs. (ouch!)