Brake noise

Assuming the rotors were turned, it's possible that the pads are grinding against the edge of the turned area. Wheel bearing play can cause a similar grinding sound. If the pad backing plate (part of the pad) is undersize, it may allow the pad to move enough to contact the edges of the turned area, and cause a grinding sound.

It all depends on what you mean by "grinding noise". Brakes work by rubbing things together (pads and rotors), so it is inevitable that some sound will result.

As a rough guide: if you are backing out of your driveway, the motor is idling, the radio and A/C are off, the top is up and you brake, it is very likely you will hear some sort of sound. It's absolutely normal.

After washing the car, some water remains on the rotors. The water eventually evaporates, but will likely cause some rust to remain on the rotors. When you apply the brakes under this condition, there will be some "grinding" to be heard until the rotors clean themselves up. This takes a couple of stops.

Brakes are probably the most foolproof replacement item on your car. It's really difficult to screw up a brake job although, I'm sure, it has been done. In your case, you had the job done by someone who apparently had the skill to overhaul the calipers, bleed the system, etc. as well as doing the much simpler task of changing out the pads. You then had the work validated by a second (I'm assuming "competent") mechanic who said everything was fine.

It is not possible to accurately diagnose something like this from a distance. Does this scenario come close?

Best,

Ken

My nephew had extreme brake noise (on a non-Miata vehicle), squealing like mad and then fading. He figured he'd blown a caliper and went nuts over the weekend trying to find one *and* get the car home safely. Finally got the parts and got home. He and my brother jacked the car up, pulled the wheel and found that the morons at the garage had left off a clip of some sort so the piston of the caliper was only partially engaging the pads.

So, yes, screwing up a brake job *can* be done. ;)

Iva & Belle.) '90B Classic Red.) #3 winkin' Miata

Hey, hey, hey, I did that once. I have also installed a shock and then looked down to see the plastic shim on the ground afterwards.

I can screw up ANYTHING, given enough time, but it usually works out. It won't be too long before a decade has passed since I have taken my car in for mechanical repairs, so I must be doing something right. :-)

Pat

I really don't think the grinding sound is the brakes. it is more a grinding sound the car makes as a result of my braking. When I am flying down the street and have to stop for a light and i press on the brakes i get the sound, if i lift off the brakes it stops and starts again when i press back down. It could be weather related because it happens for days then not for days. I do live in Arizona so we don't have alot of "weather" mostly hot and dry. so i am thinking something (rubber padding) may have dried up and fallen off,(happens alot around here) and now i have metal on metal. by the way, it was making the noise before i had the brakes done, that is why i took it in in the first place. turns out one of the calipers was leaking. could that have sprayed on something that causes this? I don't know, i am a girl with no car skills. Maybe she is just old. I know i make alot of noises that i never used to make.

Thanks, Iva. You have restored my faith in ... well...something.

Ken

Does it happen when it is hot and dry or, as is your current situation in Az, when it rains?

Ken

I don't think it happens so much when it is raining. More when it is dry. But it is happening alot right now. The air is cold and not as dry as normal. I might have to start keeping a log since it comes and goes.

OK...more questions:

Is the sound coming from the front or back? When you had the work done on the brakes; was that on the front, back or both?

Ken