The Audi Disc Brake Caliper is one of the few parts on your German made car that if not damaged too badly can be rebuilt by a qualified mechanic. The place on the brake caliper that has to be inspected is in the sleeve where the piston travels. If pits are present, then the chances of just rebuilding the caliper are significantly reduced. The rebuilding of this part today is generally done at a secondary shop where time is not of the essence. Each of your Audi brake calibers that need to be rebuilt will have to be torn apart and the sleeves honed out before they can have new seals put into place. This is a time consuming process and has to be right the first time, so a rush job is not permitted. Since most Audi owners like to have their vehicles back from the shop as soon as possible, the use of rebuilt brake calipers are used and installed when necessary. The time required for installing a rebuilt one is the same as a new brake caliper only the cost of the replacement part is less expensive. The main reason for this part of your Audi to be replaced is because dirt and or moisture has entered your braking system and corroded the walls in the cylinder of your caliber forming pits. The damage is that the pits could cause the piston to freeze in place causing a brake failure when they are needed to be used on the road. To help prevent this from occurring on your Audi, the brake fluid should be periodically changed and always changed when one or more of the brake calipers or master cylinder is replaced. This maintenance procedure will help keep your braking system in great working order and keep you safe on the road.