Brake Locking on Super M

I have a Farmall Super M. I replaced the brake disks, balls, and springs on one side. I also had the inner parts sandblasted and had a small amount of the surface where the pads meet machined to insure smoothness. This should be like new. That wheel continued to lockup. It locks so tight that I have to back the tractor up to unlock it and it does so with a bang. The brake (side) that I did not replace parts works without locking up, but has poor braking. I have taken this (repaired side) apart 4 or 5 times. Everything is as it should be. I have asked several local mechanics and no one can tell me the cause. That wheel locks so badly that I almost rolled the tractor while going down a hill, fortunately a tree stopped me from sliding sideways. I can not use the tractor this way, since I live in a hilly area. I do not know what to do anymore. A guy at a local machine shop who sandblasted the parts and turned down the surfaces said he has a "M" with the same brakes and he has the same problem. He said there is no fix for this except to take the "damn thing" apart every time he uses the tractor. The last time I had it apart I put some oil on the splined shaft and the brakes worked perfectly for a week, then all the locking up started again. What the heck is the problem? I am about ready to sell this tractor and get another "H" like my old one which had trouble free reliable band brakes. These disk brakes are horrid, but I hope someone on here knows what to do, since no one locally seems to know.

Thanks

George

Hate to be the one to say it, but if the brakes were badly worn overall, that's what will happen if you only do one side. If you can't slack off the good brake and tighten the worn one to get them in balance, it only folllows that one side of the tractor will stop faster and harder than the other.

That and having the splined shaft clean, with nothing more than a touch (maybe! at most!) of graphite is to be preferred to an oily or greasy lube, which will only accumulate dirt and cause the discs and plates in the middle to bind on the shaft. Next time you open them up, clean that shaft and the internal splines on the moving parts with a brake cleaner. They're normal operation will be better dry than gummed up.

Other than that, it may also be, if you had the cover planed down, that they took too much off and there isn't room for the discs to float.

I"ve been a Farmall mechanic for too long but just recently discovered something that may help you. First be sure that the bull pinion shaft splines are smooth enough that the disks are not binding, you said that after you oiled the brake it was fine for a while so maybe the oil or grease kept the disks from binding. Then what I"ve found is that the wear of the drum, the acuator and the retainer is enough that it lets the actuator balls travel too far up the ramps spreading the actuator so much that it locks. I"ve had luck by replacing actuators with less worn ones or A&I Products has new ones. I also turned down the drum mounting face on a couple tractors only about .030 New actuators is the best fix.

Only doing one side will cause uneven braking, but it will NOT cause the one good brake to LOCK UP so tight that you have to back the tractor.

You need to machine down the brake drum to compensate for the machining done to the actuators. Knock the mounting surface of the brake drum down by the same amount as what you took off both sides of the actuator combined first. See if that helps. If not take a little more off at a time until things improve.

trulyred is right, the actuators are opening too far, because there's too much clearance inside there.

You can send your drum and actuator off to OEM tractor parts, and they will get everything in spec for you. It's not cheap but maybe cheap insurance to know that it will work when you get it back?

I need to pull mine apart and put some more HIGH-TEMP anti-seize on the rollers. The copper-based stuff won't gum up like the graphite-based. When I was using it regularly, I cleaned them up and re-anti-seized them once a year.

I have to get those bearing cages in, I think that will help with mine locking up.

I always kept a large wrench on the PTO lever. Reach down and smack the face of the drum hard. That will usually release them.