I have a new 2012 mustang GT with just under 5000 miles (no brembo package). For the first 3-5 stops, the passenger front brake squeals loudly right before coming to a stop, then goes away for a while. Intermittently, while the car is warm, it will squeal very loudly at low speeds when coming to a stop (10mph). The car does not pull and the stopping power doesn’t seem to be affected. I’ve taken it to the dealership, they say they can’t reproduce the sound. They resurfaced the rotor and claim that nothing is wrong with the brakes, but the resurfacing did nothing to fix the problem.
Any clue what I can tell the dealer to fix… Every day when I leave work, my first stop is at a stop sign where many people I work with are crossing the street, and it deafens them as I come to a stop.
When brakes squeal it usually means the friction surfaces between the brake pads and the brakes rotors aren’t happy with each other. This can sometimes happen if the brakes aren’t properly imbedded or broken in properly. I would start all over again with new rotors and new brake pads. And then take the vehicle for a drive on a road where you can get the vehicle up to 40 MPH and then then firmly apply the brakes. Repeat this 3 or 4 times allowing a minute between braking events to allow the brakes to cool back down.
Usually that squeal is due to the pads, not the rotors. Maybe one of the pads doesn’t have the required shims. Some of the new brake pads have a coating on the back so that shims are not needed, possibly this coating is too thin on one of the pads. New pads would be a good start.
Leave it with them overnight with instructions on what conditions will produce the noise. The most common cause of squealing is as keith described, the pads are vibrating in the caliper. The question is, why? I would wonder why the dealership mechanics would resurface the rotor but not inspect the caliper and replace the pads at the same time they installed a freshly machined rotor. Fairly cheap insurance against a call-back. But they need to reproduce the sound to accept responsibility for fixing it so that is the first step…