VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1933-1936 Rear brakes on 1936 Master

Yesterday I changed the brake shoes on my '36 Master but the drums went back on kinda tight. The wheel cylinders are adjusted all the way down. I was wondering if that normal with these years. I double checked all the components and I think I put everthing together right. What do you think?

Are your new brake linings the correct thickness or are they thicker than the old linings?

:) :grin:

This is rather common with the Huck brakes and modern shoes.
There is an eccentric bolt adjustment that needs to be made also.
Its the bolt that hold the parking brake lever to the top of the shoe.Turning the bolt moves the rod that connects to the opposite show-spreading the shoes farther apart.

Yes, I did adjust the eccentric nut so that it was in the lowest position and the drums were still a little tight. I think that the shoes may be a little thicker. I can turn the drums by hand so I think that they will wear in.

If you stomp on the pedal a few times with the drums on the shoes may center.

I have a similar problem only a bit worse. I just put all new brake parts on the rear, and everything seems to be installed correctly. The eccentric bolt is set for minimum distance, and the wheel cylinders are turned all the way in. But I can't get the brake drums on at all. The replacement pads are probably thicker as mentioned above. The drums are also NORS, but even my old drums won't go on. I don't have an accurate way to measure the distance between lining surfaces to compare to the drum inner diameter, but they're pretty close. I'm guessing the drums would have to be turned about 1/16" at most.
Should I turn the drums? Maybe my old original drums, since they're gouged anyway? I'd try to find some other brake linings that are a closer fit, but the lining thickness is not listed in any of the catalogs? Any idea where one can get thinner linings, preferably already installed on the core?

Hi Randy,

Your problem is typical. Under normal circumstances, your shoes would be "arced" at the time of brake rebuild. The machinist would measure the inside diameter of the drums and arc the shoes to fit. You have two choices. Remove the shoes and take the shoes and drums to an old brake shop that still has the equipment to arc the shoes. The second solution is a last resort. Use 80 grit sand paper to sand the shoes down. Problem here is getting it even all away around. Much trial and error.

DO NOT TURN THE DRUM DOWN! Shoes are easy to come by, not so with drums.

Thanks. I'll start calling around to brake shops.

Randy,
Try this-Remove the parking brake link that runs from the lever to the rear shoe and see if the drum slips on.Usually the adjusters will retract far enough but the parking brake linkage is the problem.If this solves the problem the slot in the link that the lever fits into could be made deeper.

The parking brake linkage was completely bottomed out (lever in slot), so I don't think it could have gone any farther. I already have everything back off again now, so while it's off, I think I'll try your suggestion and make the slot a little deeper.

Ray hit the nail on the head. Us "old timers" remember when shoes had to be arced each time the shoes were replaced. It was standard practice. For you young whippersnappers, arched means to turn the linings perfectly round to fit inside the drum, that gave you almost 100% shoes against the drum. Usually, most of the lining that was removed is at the end of the shoe, and I'll bet thats where yours is hanging up. You may have to get out the old grinder and do a little fitting. Start on the ends. You could also make of a pattern of your drum, and lay it up against your linings and get an idea of how much you need to take off. Perfectly clear eh?

Arcing brake lining has been outlawed for many years due to the asbestos dust it creates.Doubt if there is a shop that will even admit to having the machine.

Gene, thanks a million. You nailed this one. The drums went on fine with the emergency brake linkage disconnected. Your suggestion of making the slot deeper worked! I used a hand file and took off a little at a time. I had to take off about 3/16" before both shoes bottomed out against the cylinder screws, with the screws all the way in. At that point, the drum went on snug, but it went on! I could get it back off too. After taking the drum off and on a few times, it went on more smoothly. I think that's a good starting point until I have all the brakes done, with fluid, and can tap the brake a few times to center everything.
I can't thank you guys enough. I'm still a novice and could never get through this without your help.

Gene touches on a very important point about the asbestos issue. In the olden days we were pretty cavalier about asbestos dust and that may be why we don't see too many old brake men. I can't overstress the dangers of asbestos dust...it's a proven killer and not to be messed with. Breathing worn brake dust or sanding new linings to fit can be extremely hazardous to your health. We need to keep all of us going for many more miles, so like the old desk sergeant 'Hill Street Blues' would say...'Let's be careful out there'!
Coach

You're absolutely right about the asbestos. I tried to avoid it in this case, and was ok on one side. But on the driver's side, even with the linkage slot filed down and the brakes bottomed out on the cylinder screws that were turned all the way in, the drum still wouldn't go on. I did have to sand a little on the linings (mostly the ends), but wore an appropriate respirator and gloves. I vacuumed the dust immediately afterwards. I wouldn't want to do this everyday, even with the precautions. The asbestos fibers get lodged in the lungs, and its effects are cumulative and permanent. Chronic, long-term exposure leads to shortness of breath and often cancer. There's no real cure. So the best advice is to stay away from it.

Rather than sand it would better to use a wood rasp to remove material (no dust). Clean up is easier too.

In my first life working in the parts department of a large Chevrolet dealership I inhaled lots of asbestos dust. The large parts counter window faced the center of the service department. It was customary for the mechanic to remove the drums and use the air hose to blow out the dust klinging to the shoes and backing plates.We would choke on the fine dust and much was inhaled.I am surprised that I am still alive.....maybe just lucky.This went on for the 27 years I was there.Asbestos was not on the "black list" back then.