The brake discs in M3 cars act in opposite directions and have different part numbers for left and right wheels: the left one ends with an odd number; the right one with an even number. Before working, block the front tires while you turn rear wheel bolts by 1.4 turns. Take off your rear wheels by lifting the rear of the car, and don't disconnect the fluid hose; keep the caliper assembly steady with mechanic's wire to prevent damage to the line. Take out both the
Brake Caliper and its mounting bracket. Turn the 6mm hex socket tool (and some compression spray) until you free the unique fastener with its built-in notch. To free a stuck brake rotor, first loosen the retaining bolt just 3 turns. Spray oil around the rotor contact point with the hub, then thread in two wheel bolts about 10 turns each. Tap the stationary rotor firmly from its flat side to break it loose. When installing the rotor, make sure it's good condition, remove any protective coating, and continue installing. Wash both rotor and hub surfaces clean, spray on anti-seize grease, and install the rotor onto the hub using a 12 ft. pound (16 Newton-meter) torque. Tighten the parking brake until it holds, then put on the wheels and secure them with hand tightening on the lug bolts. Move the vehicle until tires touch the ground, and apply enough turning pressure to lug bolts using a cross-pattern for 66-81 ft. lbs. (90-110 Nm). To make sure your brakes stop you whenever you need them, do this: bring the car to a complete stop five times at 30 mph, wait for your brakes to cool, do it all over again for another 5 stops, then repeat if needed. You perform the same inspection steps to check the rear brake rotor as you do the front one.