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Old 02-01-2025, 04:09 PM   #54
Mad Mac
Senior Member
 
Join Date: Mar 2013
Location: New Zealand
Posts: 412
Default Re: Rear brake adjustment

Quote:
Originally Posted by J Franklin View Post
Hey, where did you go? have you had any insight into the problem? I was almost thinking we were conversing with an AI.
Hi again,
I am not a robot – I am someone who has a lifelong love/hate relationship with his 1929 Model A Roadster pickup (owned by me for 55 years).
Since my last post I decided to take a break and think about the problem for a few days. Recently I have done more things to identify the cause of the brake drum binding. I have:

(1) Temporarily removed the e-brake assembly from its backing plate (binding continues so that was not the cause).
(2) Confirmed that the heads of the service-brake pins are properly seated on the roller track.
(3) Chamfered the leading and trailing edges of the service-brake linings
(4) Slightly bevelled off the outer vertical edges of the service-brake linings
(5) Applied chalk to the service-brake linings to observe high spots (there was one very small one, now sanded down).
(6) Measured the thickness of the service-brake linings at 5mm (should only be 4.78mm (3/16") but that is a very small difference.

Disappointing to find that none of these actions reduced the binding of the drum sufficiently to avoid over-heating.

I wonder if the linings are contacting only a narrow part of the brake drum, because when fully tightened the drum is very close to the backing plate. And when I release the axle nut and pull the drum out by about ¼ inch, the drum is then freed up. The axle already has 2 shims, but should I apply more?
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