A couple of months ago I had my front brakes replaced, but the rear ones did not need to be replaced yet. After I had my rear brakes replaced more recently, they started making what my girlfriend and I have been calling the dove sound. The sound started as soon as we got the car back as far as we can remember.
It makes this rubbing/squeaking hoo-hoo-hoo sound when you apply the brakes. It’s very rhythmic - it sounds like it makes the sound in the same “spot” every time (at least that’s how I think of it) i.e. it starts off faster when you start to brake and slows down at the same rate as the car slows down (It would be a lot easier to describe if I could just make the sound haha).
We took it back to the mechanic twice. The first time he was just kind of vague but reassuring and said it was no big deal. The second time we took it to him (still worried we were causing damage) he explained a little more and said it was because the shoes were extremely hard and it looked like they were brand new despite putting over 1,000 miles on them since they had been changed. He said it was nothing to worry about and the sound should go away once they were more broken in.
Now it’s been about 2 weeks since that most recent visit, and the car still making the sound. Is this something to worry about? Should we take it somewhere else? What is causing this sound?
Thanks for any help you can give!
1,000 miles is more than enough to “break in” new brake shoes. 100 miles is enough.
New brakes should not make any strange noises, and you shouldn’t notice anything different than before you had the brakes replaced.
Does the mechanic hear and acknowledge the noise? I can’t tell you what’s causing the sound, but I can tell you it shouldn’t be there.
The mechanic did hear the sound. He looked at the brakes, said that they look fine, there’s nothing to worry about and the reason it’s making the sound is because the shoes are very hard. That’s as much as he told me. I’m assuming that it’s not a safety issue and hoping that he’d have done something about it if he was worried about safety, but is it causing any damage?
Were the rotors replaced too? If so, perhaps he didn’t properly clean the preservative oils from the rotors and there’s a hardened spot of burnt presevative on one of the discs.
It’s unfortunate that you now have to rely on him to correct the problem. He seems uninterested in pursuing the cause.
I’m also wondering how he knows the pads are “extremely hard”. Did he do a Rockwell test on them? I think he’s passing gas through the wrong end.
As a minimum he should burnish the disc surfaces.
Haha I believe he was saying they were extremely hard because he put on a type of shoes that are harder than most? I know little to nothing about cars so this didn’t really strike me as strange. Should it have?
The rotors were not replaced nor reground as far as I know. I know that because we let the front brakes go too long and the rotors had to be replaced or reshaped or whatever they do to them when you let them go too long. I believe it was just a standard brake change (whatever that entails) because he didn’t tell us anything beyond that and he’s usually fairly good about giving us the details of he did.
If it’s not burned on preservative oils, what else could it be? Thanks for the responses you’ve given so far!
When the brakes are let go too long then the rotors either need to be replaced or “turned”. “Turning” is a skim-cut on a special lathe set up for brakes that returns the frictional surfaces to parallel and flat condition. There needs to be sufficient material on the rotors to do this. The shop will have checked the requirements before starting. They’re stamped into the rotor.
There are only fours types of pads commonly used
and I never thought of any of these being extra hard. Nor have I ever heard one causing a sound like a Dove. Perhaps a dust shield is vibrating. Just a wild guess, something nobody checks.
Correct me if I am wrong. All Corollas I have seen have drum brakes in the rear. If the drums were not machined (turned) or replaced it is possible that they are warped. Usually a brake shop turns or replaces the drums because the fresh surface allows the brake shoes to break in. If the drums are not scuffed up, it is possible that the new brake shoes will get glazed and make noise.
In days of yore, the shoes were arced to match the drum diameter. However, this practice has been discontinued due to the health hazards of brake friction material dust. So now the brake shoe has to wear itself to match the drum. If a hard material is run on a used drum surface, it can glaze before it beds in.