The brake caliper is secured to the caliper bracket, which is attached to the steering knuckle. To release the tensioning spring from the brake caliper, use a suitable pry tool, and remove the protective caps to access the caliper mounting fasteners. Rock the caliper back and forth several times, then slide it along with the inner brake pad away from the brake rotor. The inner brake pad is held onto the piston by spring clips, while the outer pad is installed on the caliper bracket and can be removed or installed by sliding it out of the caliper mounting bracket. Proper installation of the caliper slide bolts requires a hex socket and a torque wrench. Begin by blocking the rear wheels and applying the parking brake, then loosen the front wheel bolts slightly, raise and support the vehicle, and remove the front wheels. Disconnect the brake pad wear sensor if equipped, hold the flats of the pin slide, and remove the lower pivot bolt to rotate the caliper up and remove the brake pads. For installation, clean the brake caliper and sliding surfaces, press the caliper piston fully back into the housing, and check for leaks, damaged dust boots, and frozen pistons. If the plastic part of the brake pad wear sensor is worn through, install a new sensor, then connect it to the harness ensuring a good connection. Install the brake pads in the caliper mount, lower the caliper over the pads, and install a new bolt, torquing it to 25 ft.lbs. (35 Nm). After installing the wheels and hand tightening the lug bolts, lower the vehicle and torque the lug bolts to specification in a crisscross pattern to 66-81 ft.lbs. (90-110 Nm). For inspection, check the pad thickness, condition of the brake friction material, and wear pattern. If the inside pad is worn more than the outside pad, the caliper may be seized on the sliding pins, requiring cleaning and lubrication. If one caliper has significantly more wear than the opposite side, check for issues such as a frozen caliper, blocked brake line, or binding pads. To test for binding or insufficient release, raise and support the vehicle, put it in neutral with the ignition off and parking brake released, and have an assistant apply the foot brake while attempting to rotate a wheel. The wheel should not rotate under brake application and should rotate freely when the brake is released, indicating proper caliper function.
Posted by BMWPartsDeal Specialist 
