I've always felt whomever designed the brakes on that should be disinterred, biach slapped, then maybe fed to the fish. The brakes on this thing are useless. Not being the owner, I finally went to fix some things on it, brakes being one. I got them improved but never really working like I'd want.
I have to agree those style brakes can give you fits, but unless the bull pinion shaft seal is leaking, they can be cleaned up well and work like new again. I have 4 IH tractors here with that style brakes on them and also had and old Case 310B backhoe with the same style brakes but got them all working very well.
It seems that at times, pressing on the brake pedal is like stepping on a plum, and you get very little braking action. The brake discs get what appears to be a waxy surface when you get them out. If they are not oil soaked, you can buff the surface with 100/120 sandpaper and rough them up a little. I now use my air angled die grinder with the 2" roloc disc head, and generic medium fiber type roloc gasket removal discs. 10X faster than using sandpaper and leaves a slightly rough surface.
The other problem is when you press on a brake pedal a wheel will lock up and most times stay locked. Putting it in reverse will unlock it. This is due to the large ball bearings getting rusty, along with the ramps. These too can be cleaned up with sandpaper, or as I now use my die grinder with disc. They do sell new ball bearings which I believe are 7/8" in dia. I did replace the ones on the Case hoe because they were really pitted. Everything else just buffed off. The 2" disc will clean up 90% of the ramps, just the very bottom needs finished with fine sandpaper (I use wet & dry 120 grit as it seems to hold up better and more flexible).
I then coat both with a light film of never-seize, using my fingers. Just put a small blob on with the brush, then use my fingers to smear it around. Too much and it could get on the braking surfaces. Reassemble and adjust, you're good to go.
You do have to be careful when removing the little coil springs as the hook will break off and you'll need new ones. But some are rusted so bad in the hook they will break no matter how careful, or just plain worn. With having that many tractors with them on, I have a few spares in the parts cabinet for just in case.
I've found over the years this happens more on my Super C's than any of the others, and normally after 3-4 years and going through the Spring sweats here. When it's been cold, then get a day when it warms up into the 50's-60's and condensation forms on the cold metal setting in an outside unheated building. Normally they will get a little sticky before getting to the full locking stage. When I notice it, I know it's time to take it to the shop and do some cleanup.
I bought my air angle die grinder at Harbor Freight back in the late 80's when they were mail order only, and grinder was made in Japan, not China. I must say, it still works very well and use it quite often. Got the Roloc head at NAPA, but there are many brands now for a lot less. The discs I get at a local Swapper's Day over the Labor Day weekend off a tool guy there. I get 50 in a box for $20, but get a break is I buy 2. They seem to last just as long as the 3M brand which are a lot more expensive. This tool guy also sells them on ebay, but for a little more to cover cost of shipping. I go through a lot here, as it seems I'm always working on something. Great for buffing/cleaning gasket mating surfaces. Sure beats doing it by hand.
Just some food for thought on the grinder/Roloc style head. One of those tools once you use one, you'll wonder how you got along without one. Did a quick check and for around $50-$60 you can get one of the better, not professional grinders, a generic Roloc head, and a box of 50 aftermarket discs. That is if you have a decent compressor to run it.