Causes of drum brake noise - drums or hardware?

Joined
Jan 2, 2004
Messages
10,013
Location
California
Here’s something I was thinking of recently - what’s the most likely cause of drum brakes being noisy?

I was chasing down a rear chirping noise from the rear of a van. The brake shoes were replaced with OE Toyota shoes. Shortly after, chirping sound at low speeds and braking. I had a local machine shop turn the drums(OE Toyota from 2004) and roughed up the shoes with 120 grit paper. Still happened. Replaced the drums with new OE(me & @The Critic talked about his and he’s told me Chinese drums are iffy), and decided to replace the hardware with whatever the parts house has. Carson, made in China. Applied a smear of Permatex Purple lube to the backing plate-shoe contact points. Problem seems to be solved.

So what would be the most likely/common cause of drum brake noise - out of round/improperly machined drums or old brake shoe hardware seeing heat cycling and springs losing their temper, as a result not as “springy” as they were?
 
Joined
Sep 16, 2022
Messages
13
Years ago I had the same problem. Replaced the rear brake drums that had been machined the year before and the noise went away. The only other thing I noticed was that with the parking brake applied about half way, I could easily feel that the drum was eccentrically machined.
 
Joined
May 21, 2018
Messages
3,364
Location
South Carolina
If the brake drums get hot they will temper and make noise. The most common problem is if the brakes overheat and the springs get hot and lose their temper and get soft as you mentioned. The culprit is the hold down spring. The small round one in the center of the shoe. The other failed springs will cause the brakes to drag making the situation worse.
Always clean the pads on the backing plate where the shoes ride and make sure there are no grooves in them from weak springs and vibrating shoes. We used to use a grinder to flush out the grooves if they weren't too deep. Lubing them is a good idea along with the threads on the adjuster. Some people us special lube but I've been using never seize for 50 years.
 

nthach

Thread starter
Joined
Jan 2, 2004
Messages
10,013
Location
California
If the brake drums get hot they will temper and make noise. The most common problem is if the brakes overheat and the springs get hot and lose their temper and get soft as you mentioned. The culprit is the hold down spring. The small round one in the center of the shoe. The other failed springs will cause the brakes to drag making the situation worse.
Always clean the pads on the backing plate where the shoes ride and make sure there are no grooves in them from weak springs and vibrating shoes. We used to use a grinder to flush out the grooves if they weren't too deep. Lubing them is a good idea along with the threads on the adjuster. Some people us special lube but I've been using never seize for 50 years.
I applied Permatex purple lube on the backing plate and the shoe contact points. I figured the tiny bit of “ceramic”(really zinc oxide and boric oxide per the SDS if disclosed) would be good boundary lubrication as well as a little Super Lube on the adjusters.

Yea, I’ve read back on the olden days it was common practice for a brake shop to reline brake shoes in-house and grind them/index them to fit the drums.
 
Joined
Feb 6, 2021
Messages
1,023
Location
Massachusetts
Here’s something I was thinking of recently - what’s the most likely cause of drum brakes being noisy?

I was chasing down a rear chirping noise from the rear of a van. The brake shoes were replaced with OE Toyota shoes. Shortly after, chirping sound at low speeds and braking. I had a local machine shop turn the drums(OE Toyota from 2004) and roughed up the shoes with 120 grit paper. Still happened. Replaced the drums with new OE(me & @The Critic talked about his and he’s told me Chinese drums are iffy), and decided to replace the hardware with whatever the parts house has. Carson, made in China. Applied a smear of Permatex Purple lube to the backing plate-shoe contact points. Problem seems to be solved.

So what would be the most likely/common cause of drum brake noise - out of round/improperly machined drums or old brake shoe hardware seeing heat cycling and springs losing their temper, as a result not as “springy” as they were?
Chirping at low speeds when braking is almost always improper adjustment.
 
Joined
Jul 16, 2005
Messages
584
Location
Montague, NJ
IMO actually both. Poor out of round drums and old hardware. Hardware kit is cheap and new springs/kits should go in with new shoes so self-adjusters work properly. Clean backing plates and proper lube of contact points also.
 
Joined
Apr 18, 2013
Messages
1,233
Location
Kevil,Ky
If I had a drum making a humming noise then I would install a screen door spring around the drum. It would stop the noise and fix the problem.
 
Top