Adjust Brake Shoes

[johnr9q@yahoo.com]

On the front brakes, I turn, the adjusting stud and the left side brake does nothing and the right side brake just goes in and out a little but doesn't change position. Are the adjusters bad and what do I need to do to fix them?

 

[rotorwrench]

The top adjustment is a conical shaped wedge where the cone allows the rotation to expand the top out toward the drum to get proper clearance. The roller wedge mechanism is the actuator that expands the shoes with the push of the pedal. Arcing the shoes to the drum when new, is the most important step of a brake job. The other adjustments are the final steps to reliable mechanical brakes.

 

[Phil Brown]

The adjuster is on the top as you noted and set's the gap between the shoe's and the drum. The other part "the wedge shaped thing" is pushed down when you push on the brake pedel and pushes the brake shoes outward aganst the drum to stop it's rotation

 

[nkaminar]

John r9q, It sounds like you need to overhaul the brakes before doing any adjusting. The Red Book, https://www.snydersantiqueauto.com/product.htm?pid=980031&cat=41621, is probably your best "how to" book. The wedge should have 3 distinct sections but a lot of them are worn and do not work as designed.

 

[JayJay]

On the front brakes, it looks like the adjustor is on the top but what is (and what does it do) the wedge shaped thing at the bottom that slides up and down? Also, I turn, what I think is the adjusting stud and the left side brake does nothing and the right side brake just goes in and out a little but doesn't change position. Are the adjusters bad and what do I need to do to fix them?

It sounds like you have the front hub/drum removed from the spindle.

Here's how the brakes work:

1. The wedge at the bottom has a shaft coming down inside the spindle that goes to the top. You can't see it easily. When you press on the brake pedal, the brake rod moves rearwards. This rod connects to an arm that turns, and an internal lever pushes that shaft downwards and pushes the wedge downwards. That downward movement of the wedge in turn presses the lower edges of the brake shoes outwards to grip on the drum.

2. The adjuster at the top moves the top of the shoes so they just miss touching the drum when the pedal is relaxed. There is a shaft on each shoe that goes into the adjustment housing. Turning that adjuster should move each shoe inwards and outwards equally. If one shaft is "frozen" then you might want to remove the springs, remove the shoes, and clean/lube those adjuster shafts.

Taken together and properly adjusted, the wedge spreading the shoes at the bottom pushes the shoes outwards so they contact the drum equally on all surfaces. You can look at the surface of the shoes, and the thickness of the friction material, to see if you've been getting good contact. If not then maybe a refurbishment of the front brakes might be in order.

 

[JoeCB]

A common 12 point socket will fit a square nicely...just search your tool box for one that fits.. it may be imperial or metric.

Joe B

 

[johnr9q@yahoo.com]

Thanks everyone for your help