Farmall Super M brakes are very poor

chappie

Member
I have a Super M with disc brakes. About 5 years ago I replaced the brakes discs on the left side and at the time, I replaced the springs, and balls too, as well as the adjuster bolt (which was bent).

I never rebuilt the right brake, because it's coated with grease, so I guess the seal is leaking into the tranny, and I'm not into ripping apart the whole tranny to change it.

So, I've just learned to use only one brake, which used to work fairly well. But lately they have gotten real poor and I actually had to jackknife my hay mower last week in order to stop on a hill. That's when I decided it's time to replace the discs again on that left brake. I just took them apart and found those discs are almost like brand new still.

The springs are fine and the balls are round and aside from a few specs of minor rust they look perfect. However, I did find a lot of dirt and crud in the bottom of the drum, which I wonder of that was causing some of the poor braking. I washed everything well, using dish soap and water, and will wipe the balls and their grooves with alcohol.

I also found the discs are very shiny. Should I run a belt sander across them, or at least sand them by hand? And I suppose it would not hurt to sand the mating metal surfaces too.

Otherwise, I dont know why that brake got so bad recently.

Lastly, should I apply a light coating of grease on the balls and on the spline?

By the way, the backing plate which the brakes contact, which is the part against the tranny, appears to be a separate piece. Does that come off? (I dont really need to remove it, but if it comes off, It would be easier to sand it.)
I tried to hammer a screwdriver in the gap, and got 1/16" space, but it feels like something else is holding it.

Thanks
 
DO not pry on the backing plate. TO fix the seal, it is only necessary to use some drive screws and a small slide hammer to pull them out. to be replaced (new ones are thinner and can be positioned so the lip does not run in a groove.) The brake issues might be total clearance when released. Take off the housing and clean things up. place the outer disk, expander/balls and other expander (assembled) then the inner disk into the housing. (lay it on a pair of 2X4 blocks to keep it flat on the bench) now measure down to the stack of parts from a straight edge placed across the mounting surface. The clearance should be less than a dime, and more than a match book cover. If much more than the dime, they will not work well because the pulling linkages are not at a good angle to rotate the plates. This is reality! .030 to .045 will do. Machine shops can mill off the excess for a small sum. The wear is on all 4 surfaces, but the mating surface (measured from) will be the place to machine off material. Jim
 
Ok, I wont touch the backing plate anymore.

You've lost me completely on the seal? Where is it? What do you mean by "drive screws"? Where do I use them and the slide hammer?????

I guess you mean they machine off the lip (outer edge) of the drum, right? I suppose this is to make up for wear inside the drum.

One other thing, that actuator has the two arms that go to the center piece and is bolted to the part which attaches to the adjuster. One of those arms has a lot of slop (wear), where it attaches to the metal piece which holds the balls. It appears that is a rivet to hold it on place. If I grind off that rivet, and fill in the slop on that arm with a welder, can I just put a bolt in there?

Yea, I suppose I should get a new actuator, but they are $200 (each). I plan to trade this tractor in soon, because I need something with live hydraulics and 3 point, (like some of the Farmall 500 series) so I dont want to spend a lot on it.

Thanks

(quoted from post at 22:55:30 08/30/15) DO not pry on the backing plate. TO fix the seal, it is only necessary to use some drive screws and a small slide hammer to pull them out. to be replaced (new ones are thinner and can be positioned so the lip does not run in a groove.) The brake issues might be total clearance when released. Take off the housing and clean things up. place the outer disk, expander/balls and other expander (assembled) then the inner disk into the housing. (lay it on a pair of 2X4 blocks to keep it flat on the bench) now measure down to the stack of parts from a straight edge placed across the mounting surface. The clearance should be less than a dime, and more than a match book cover. If much more than the dime, they will not work well because the pulling linkages are not at a good angle to rotate the plates. This is reality! .030 to .045 will do. Machine shops can mill off the excess for a small sum. The wear is on all 4 surfaces, but the mating surface (measured from) will be the place to machine off material. Jim
 
Screw screws into the seal from the outside to grab the seal and pull the seal with a slide hammer. If you pull the screws out move around and pull from a new spot. By the way, if you're used to using an M you might be unhappy with the additional repairs and complexity of the newer tractors. I was.
 
No need to go in transmission. Plate on left comes out to replace seal with no other parts removed unless wanted. May need to replace the O ring also. Instead of using pry slots I find it easier to screw a slide hammer in the pinion shaft threaded hole at end. If gear and bearing looks good just slide back in after plate removal.
a199757.jpg
 
That picture really helped. I still dont see the actual seal, so I assume its inside that backing plate, about the same depth inside as that O-ring.

Do I have to worry about my gear lube running out from the tranny?

Also, we no longer have a local Farmall IH dealer. I was told that NAPA could get the seal, if I know the part number. How can I obtain the number? And I may as well replace the O-ring too. Is that sold by part number or measurements? Hopefully NAPA also has a slide hammer, that is one tool I dont have.

I'm still concerned about the large amount of slop (wear) in that one arm where it attaches to the actuator. I'm seeing close to 1/4" slop, where the hole is elongated that much. Rather than buy a $200 part, I know the local machine shop will do it for less than $10.

Is it that slop in that arm, or because the drum needs to be machined (or both), which is always causing the adjuster bolts to bend? One bent so badly that it broke last winter when I was pushing snow with the loader, and since that was my only brake, I could not stop, so I took down an electric fence and lost control of the tractor going down a steep hill. (luckily a tree stopped the tractor, or I would have flipped it). Besides that bolt always bending, the actuator arms come so far out of the drum (at the dust seal), that I had to put a large nut at the top of the bolt head as a shim, and new dust seals become torn in a few weeks. (I think I replaced that seal at least 3 times before just giving up on it).

Lastly, do I actually need new brake discs to accurately measure the stack distance to the drum, (for machining)? I planned to use the old ones which I replaced 5 years ago, and still look almost brand new? (I dont use the tractor all that much).

Thanks


(quoted from post at 08:52:21 08/31/15) No need to go in transmission. Plate on left comes out to replace seal with no other parts removed unless wanted. May need to replace the O ring also. Instead of using pry slots I find it easier to screw a slide hammer in the pinion shaft threaded hole at end. If gear and bearing looks good just slide back in after plate removal.
a199757.jpg
 
I dont have any measuring devices for thousandths, but I used the dime method. I can nearly get 2 dimes stacked under it. Or 1 dime and 3 business cards was a perfect fit. (no matchbooks handy).

I did not put the springs on the actuator, just put the balls in place and let it settle, plus have both USED discs in there which I plan to reuse after a light sanding of the surface.

I suppose after a light sanding, I will get 2 stacked dimes easily.

Now I suppose I have to determine the thickness of a dime and have that much removed. Ok, several websites say a NEW dime is 47 thousandths, but a worn one can be less. What I used were not too worn looking. So 50 thousandths might be a good place to start, I guess!




(reply to post at 22:55:30 08/30/15)
 
No gear lube loss, can see seal in the plate and easy to replace with plate off. Brake pedal travels to far and bends adjusting bolts. Keep adjusted or fix worn parts and check for to much space between plate and drum. Machine some off drum if needed. Takes a 5/8 fine thread in the pinion shaft if removing that way. Need a pretty heavy slide to get some out in a few hammers. If O ring looks good you could try a non hardning sealant and reuse. Case IH don't sell them cheap.
 
Many times you can use the sheet metal screw method without a slide hammer. A plain old claw hammer, a stout screw driver with shims to get the right "purchase" or small lady slipper bars, also known as rolling head bars will work. Miniature wrecking bar comes to mind, too.
 
Chappie,
Couple of other things-
I know we’re talking about different tractors, but on my father-in-law’s 450, the housing was a ‘weep’-hole at the bottom, to allow weepage from the transmission to drain out and not accumulate in the housing. If your M has one, make sure it isn’t plugged up with crud.

chap1.jpg


On the 450, the arms are not held to the actuator plates with rivets, but rather ‘shouldered’ bolts, which assure that a space remains so that the arm can freely rotate as it goes through its motion. These bolts, and the one that goes through both actuator arms, are so rigid and tight that there is no possible way they could ‘bend’. And I would have a welder bring that bolthole back to tolerance. This also contributes to your actuator arms coming out further than they should.

chap2.jpg

_____________________

You wrote this…

“Besides that bolt always bending, the actuator arms come so far out of the drum (at the dust seal), that I had to put a large nut at the top of the bolt head as a shim, and new dust seals become torn in a few weeks.”

… and this implies that there is way too much ‘play’ between the pads and the housing. If the pads were in tolerance, they’d grab sufficiently quickly that they would not be close to hitting and tearing the rubber dust jacket on the outside.
__________________

And you wrote this…

“I could not stop, so I took down an electric fence and lost control of the tractor going down a steep hill. (luckily a tree stopped the tractor, or I would have flipped it).”

… so please heed this- running with one brake is so risky. Do the right brake while you’re at it. This isn’t worth your life. If you had flipped that tractor, you’d likely not be here to write this.
 
Fixing the linkage is important a bolt will work with Locktite if there is clearance. Take off .050" from the mating edge of the "drum" housing.
The seal is right at the back of the splines. It can be pulled out the front toward the splines using screws drilled into the seal body, and pulled with a slide hammer. Jim
 
Ive been doing everything suggested on here. Had machine shop fix those sloppy arms. I got the backing plate off on the greasy side, without a slide hammer. I drive several screwdrivers in the gap, then went to use chisels. It finally popped. Had the machine shop press in the grease seal.

But now there's a problem. I should have left it alone, I suppose, but I pulled that shaft with the splines in them, (where the middle of the brake discs fits onto). I inspected the bearing and tried to slip it right back in. It's not going in deep enough. WHY? There's a gear, and splines on the inner shaft. Yea, both need to line up, and apparently that is not happening. I had not moved anything. Since then, I put the tractor shifter in neutral. Still it wont go in. Even though all the spline teeth and gear teeth are identical, I did try rotating that whole thing tooth by tooth. It still wont go in. WHAT DO I NEED TO DO? Thanks


(quoted from post at 11:58:44 09/01/15) Chappie,
Couple of other things-
I know we’re talking about different tractors, but on my father-in-law’s 450, the housing was a ‘weep’-hole at the bottom, to allow weepage from the transmission to drain out and not accumulate in the housing. If your M has one, make sure it isn’t plugged up with crud.



On the 450, the arms are not held to the actuator plates with rivets, but rather ‘shouldered’ bolts, which assure that a space remains so that the arm can freely rotate as it goes through its motion. These bolts, and the one that goes through both actuator arms, are so rigid and tight that there is no possible way they could ‘bend’. And I would have a welder bring that bolthole back to tolerance. This also contributes to your actuator arms coming out further than they should.

[img]https://home.epix.net/~runamuck/chap2.jpg
 

Only thing that would keep it from going back in is if the differential bevel gears are worn so much the one you need in has dropped out of center. Look with a light to see if the splines are centered in the differential carrier hole. Never run into one that wouldn't slide back in before.
 
I got it back in. Right after posting this problem, I went out there with a 3lb brass headed hammer. One tap and it popped right in. I dont like to force things, but sometimes some light force is needed. This was one such time.


(reply to post at 07:49:53 09/03/15)
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top