BMW 34216855004 Ventilated Brake Disc

Measure the brake disc diameter on the vehicle and check it against the corresponding brake disc specifications for the front or rear brakes. Additional application information is available through parts data and the authorized BMW dealer parts department. Machine or replace brake discs in pairs per axle. Begin by raising the car and supporting it safely, then remove the wheels. Next, remove the brake caliper carrier bolts and suspend the brake caliper from the chassis using stiff wire, ensuring the hydraulic brake line remains connected. Remove the brake disc mounting screw and take off the disc, inspecting it for cracks, signs of overheating, and scoring. The minimum allowable thickness is stamped on the disc hub. Measure the disc braking surface with a micrometer at eight to ten different points, using the smallest measurement for comparison against the specifications. If the disc does not meet minimum thickness requirements or is damaged, it should be replaced. Clean the disc with brake cleaner before installation, and when installing new rear brake discs, adjust the parking brake accordingly.