Heavy drag on rear drums II

[Purdy Swoft]

I don't know how your linings are tapered or if thats the problem. Here is how I taper mine. I taper the leading and trailing ends of the lining almost to the holes in the lining where the heads of the lining rivets rest. I've done my model A's this way for years.

[1931 flamingo]

There's another thread going on about noise in the rear brakes. One ck to make is the WIDTH of the new linings, possibly binding up the drums. FWIW
Paul in CT

[Ron Lowe]

When I did my brake job I replaced every part, and I do mean every part which was quit the big bucks. I had the same problem. The solution was to pack all the drums, hubs, linings, etc. and send them to a professional ( Brattons) and have them turn the drums and arc the shoes to perfectly match together. Money well spent and they work perfect. Good luck.

[Patrick L.]

Brake 'squall' is usually caused by loose linings. The shoes need to be clean, really clean when the linings are riveted on. The linings need to be properly riveted so the linings cannot move around at all.
I also agree with long and shallow leading and trailing edge chamfering. As said, its easy to sand the lined shoes to fit the drums.
The brakes need/have to be adjusted correctly and that starts with the jack stands under the axles.

[Purdy Swoft]

Here is a couple of possibilities that haven't been mentioned. If the rear axle housing outer bearing races are worn on the bottom it will effect brake operation and adjustment. The bottom of the outer housing races carry the weight of the car and do wear. When the races wear, this brings the brake lining closer to the bottom of the drum and can and will cause rear brake drag. The rear brake cams float in the rear brake camshafts to help compensate but after wear begins on the rear races it is best to make brake adjustments with the rear wheels on the ground or better the shop floor. I do the rear brakes first with the brake rods disconnected. I can push the car foward and backwards by hand as I adjust to feel for drag. If the brakes drag with the adjustment backed out all the way with the brake rods disconnected it can indicate one or more of three things. Feel the bottom of the rear housing bearing races for wear, usually one side will be worse than the other. The wear is easy to detect by hand. If the wear is excessive, the housing races can be turned down and a sleeve pressed on. The shoes need to be centered and a centering tool is needed to show what direction the shoes need to go, this usually requires mods to the brake tracks. There is likely high spots on the lining. The lining can be chalked, the drums reinstalled and turned so the chalk will be rubbed off the high spots and will show where to sand the lining, this is the poor mans way to arc the lining. There is a machine that can be adjusted to the arc of the drum and then sands the lining to the correct arc to match the drums.

As for squeal, most model A brakes will squeal at times but not every time. With steel drums it can be caused by harmonics in some cases. If the holes in the shoes are worn where the roller pins go, it can cause a squeal . Sometimes the shoes can be peined to reduce roller pin hole size. In worse cases it may be best to buy new shoes. A squall probably means that something is rubbing severely. If its that bad, I'm surprizes that the drums would fit over the shoes when trying to install. The best case would be that the brakes need to be adjusted with the wheels on the floor. Model A brakes are very simple if you take the time to look close and study how they actually work. I always adjust the front brakes with the front axle on stands, It is always best to adjust the rear brakes with trhe wheels on the floor