Brake Caliper Piston Tool Used for retracting the piston in calipers when installing new pads. Replacing brake pads or rotors doesn’t need to be difficult if you have the right tools. Volkswagen and Audi rear calipers require that the piston be rotated while being pushed back into the caliper. In addition your new brake tool will work on most other makes, take note there are 9 adaptors included.  While ordering your new rotors and pads have EPM ship the necessary tool to complete the job right. $34.99