disk brakes

My SH brakes tend to lock up and you have to back up to free them. What is wrong?

Have you done any work on them?

The root of th problem will be wear and/or fouling with dust and crud. The brakes are actuated by a couple of disks that are bound to each other by springs. They are separated by several steel balls between them, that ride in what I'd call ramps that are machined into the surface of each disk. When the brakes are at rest, the balls are in the lowest, most recessed, part of each of these ramps, so that the two discs are as close to each other as they get. Stepping on the pedal causes the rod to turn one disc against the other, which in turn causes the balls to roll toward the shallowest part of the ramps, expanding the whole mechanism to that the outer surfaces of the discs press the friction discs against the chassis and brake cover to slow the tractor. All of which will make sense once you've opened one up and see it. (I think it's the IH and I&T manuals that are notorious for saying something like "The engineering will be readily apparent upon disassembly.")

What you're experiencing is usually caused by rough or dirty surfaces hindering the free movement of the balls or discs. IF the problem is with fouling of the ramps or the balls, a little brake cleaner with a Scotchbrite pad and a little finish with some 440 grit sandpaper will generally clean those up, though sometimes the balls are pitted so badly that they're better being replaced (dealer item).

The other thing that will cause them to bind is built up rust or crud on the splines of the shaft which will hinder the free movement of the actuator and friction discs. Sometimes it's rust, which would make you think the shaft needs to be oiled. Problem with that is that oil will pick up brake dust as well as any chaff or dust that gets in there (a good argument for having good rubber boots on the rod between the pedal and the actuator), so oil is not good either. Still, leaky seals around the bull shaft are comon, and can get in there, causing dust to build up where you don't want it and, in a bad case, soak your friction discs. In the absence of a leak that has to be dealt with, about the only lube, if any, that anyone here has ever suggested would be just a light dusting of graphite after a good cleanup of the shaft.

I wouldn't be at all bashful about taking them apart for a survey and cleanup. If only one is sticking, start with that one. Once you've done one, you'll find you can do the other in half the time.

If your boots are in hard shape, I'd have replacements on hand before I started, just in case all they do need is a clean up. Try the cleanup first, put everything back together, get them adjusted properly and see how they work. If they're still acting up, then some parts replacement may be necessary for a second go at it. And, of course if you find the seals leaking oil out onto the splines, that'll have to be dealt with, but that's another project.

Let us know how you're making out.

may need adjusting, actuating balls are going out farther then ment to and not returning