Audi Repair: wheels squeaking, slide pins, temperature grease

Question
While driving with foot OFF the brakes, I am hearing a constant chh chh chh chh sound from the passenger side.  Is this a worn pad rubbing? I recently had new tires put on, and I also had to have it inspected, so a mechanic took off a wheel on the passenger side to check brake conditions.  Could this be caused by something someone else did? Should I take it back to the shop? Thanks

Answer
Hi Dave,

does the sound disappear when the brake pedal is depressed???? if so then id suspect a brake pad fault, either they are worn out or not sitting properly in the caliper. normally the pads are not meant to touch the disc until pressure is applied at the pedal, but some times dust or rust gets collected on the moving parts and the pads cannot return back to the rest position. start off with the pads, check if they are within the safe thickness limit, replace if they are not. then check that the slide pins are free to move end to end with normal finger pressure, either clean them or replace if damaged or excessively scored, when returning them back lightly coat them with high temperature grease   but do not over do it as grease getting onto the braking surfaces can spell disaster.
next use methylated spirit to wash off the brake dust, (It is safer to assume that the pad material is made from asbestos and take all necessary precautions when working on them i.e suitable gloves and mask)

also check to make sure that the back plate( black pressed sheet metal cover around the circumference is not touching the disc.

it would also be a good time to check the wheel bearing while carrying out any repairs, to do so jack the wheel up and with the tire still on place your hands at the 12 and 6 o clock positions and then move them in and out alternatively, there should be no free play, if there is then either the bearings need adjusting or replacement.