BMW 34113400151 Ventilated Brake Disc

When it comes to front and rear brake discs' replacement, one has to lift the car up and securely support it to have the wheels off. After that, remove all the brake caliper carrier bolts, but leave the brake hose connected and hang the brake caliper using stiff wire onto the intended point on the chassis. The brake disc mounting screw has to be unscrewed for removal of the disc and in the process the disc should be checked for crack lines, signs of heat and scoring. The minimum allowable thickness should be indicated on the disc hub; measure the braking surface with a micrometer, from eight to ten points and take the smallest figure. If the measured thickness of the disc does not conform with the minimum thickness or if the latter is damaged in some way, it should be changed. Before fitting, use brake cleaner to clean the disc and if you are fitting new rear brake discs, fit the new parking brake also.