Drum brake uneven friction


#1

I’ve got a 2005 Scion xB that has rear drum brakes that are the duo-servo type with the cylinder at the top. All the brake hardware is new.

I’ve advanced the auto-adjuster manually, and on both sides there’s more friction at a certain point in the tire rotation. I examined the inside of the drums but don’t see any humps. I even had them resurfaced at a shop. I keep the auto-adjuster fairly advanced because if not, the squeaking from the springs just gets louder.

Any ideas?


#2

A slight rub is fine on drum brakes.If you feel they are too tight,backup the adjuster a bit.To stop the squeeking, put a light coat of copper anti-seize on the backing plate contact points. The contact points are small raised area on the backing plate where the shoes slide on.Sometimes,people forget to lubricate these after cleaning the drum mechanism with aerosol brake cleaner.This will cause noise every time you press on the brake pedal.


#3

Thanks for the advice! I’ll try the anti seize on the contact points in the next couple of weeks and post back the results.


#4

Some out of roundness in the brake drum is normal. It’s too much though if the wheel gets pretty much stuck in one position, but is totally free the rest of the way around. On my Corolla I don’t notice any particular point where the drum sticks at all. But I do notice some normal sticking on my Ford truck. What’s normal is a little bit of drag in one position, and totally free the rest of the way 'round.

Is your actual problem you are posting about the uneven friction, or is the problem the squeaks? The squeaks can usually be addressed by using Toyota oem shoes, properly installed and lubricated on a clean backing plate. If the oem drum was still thick enough to not require replacement, it should be gone over with 120 grit al-O2 sand paper to make a cross hatch pattern on the inside drum surface, then cleaned of any grit. If the drum was on the thin side, even though technically passed the spec, replace it. If you did replace the drum, squeaking can be caused if the drum wasn’t properly cleaned before installation. New drums come with an anti-rust coating that must be removed prior to use.

Use a high temperature brake grease product for that. May be copper based. But it has to be a high temperature grease. Often it comes in the package with the new shoes.


#5

Hello, the problem is the squeaks, which I had assumed was related to the uneven friction, but after reading the two responses, maybe it’s from the backing plate, which I did not clean and lubricate prior to installing the new shoes (not toyota oem shoes)


#6

Toyota doesn’t make brake shoes/pads.

They purchase them from a vendor/supplier.

Tester


#7

You don’t need to remove the shoes to lubricate the contact points, Take a large screwdriver and pull the shoes away from the backing plate…just enough to put a thin coat of anti-seize on each contact points.


#8

I’ve done that before on my truck, when I forget to lube the contact points before installing the shoes. Works pretty good.