Dirty look?! Tell 'em to "pack it clown" or "Lighten up Francis". If, like Rocket Man said, they did not roadtest properly after the initial brake work and "seat" the pads to the rotors, that can contribute to noise problems. The pads themselves and the rotors themselves all come in different qualities as well. The least expensive attempt to try and fix this is the teardown and very close inspection, put a non directional swirl buffing on the surface of the rotor and clean liberally with brake clean to remove ANY embedded very small metal flakes, do the same to the pad surfaces and of course clean them with brake clean and use a disc brake quiet on the back of the pad and make sure the pad hardware is either new or in great shape and pins/guides are lubed and then go out and roadtest and follow this procedure:
Break-In Procedure:
5 moderate to aggressive stops from 40 mph down to 10 mph in rapid succession without letting the brakes cool and do not come to a complete stop. If you’re forced to stop, either shift into neutral or give room in front so you can allow the vehicle to roll slightly while waiting for the light. The rotors will be very hot and holding down the brake pedal will allow the pad to create an imprint on the rotor. This is where the judder can originate from.
Then do 5 moderate stops from 35 mph to 5 mph in rapid succession without letting the brakes cool. You should expect to smell some resin as the brakes get hot.
After this is complete, drive around for as long as possible without excessively heating the brakes and without coming to a complete stop (Try for about 5 minutes at moderate speed). This is the cooling stage. It allows the heated resin in the brake pads to cool and cure.
After the brakes have cooled to standard operating temperature, you may use the brakes normally.
I went ahead and copied and pasted this so that I didn't mess anything up if I had just typed it free hand. Good luck.
