Brake pads can be replaced without disconnecting the brake fluid hose from the caliper or bleeding the brakes, and rotors can be replaced without disassembling the wheel hub and bearing, with front and rear brake pad replacement procedures being similar. Always replace pads in sets, raise the car, and support it safely before removing the wheels. To measure brake pad lining thickness, use a special tool at either the right front or left rear wheel, moving the wheel until the notch for the brake wear indicator is visible. Insert the tool into the notch so that its body rests on the brake pad backing plate and the tip touches the brake rotor, replacing pads if they are at minimum thickness. Pry off the brake caliper anti-rattle spring, remove plastic caps from caliper mounting bolts, and use a special tool to remove caliper guide bolts before taking the caliper off the pad carrier, ensuring not to let the brake caliper assembly hang from the brake hose. If there is a ridge on the brake rotor edge, press caliper pistons back into the caliper before removal, then check the brake rotor thickness and inspect for rust or damage, replacing or machining the rotors as necessary. Spread the brake pads using a special tool, remove them, and be cautious as pressing caliper pistons in may cause the brake fluid reservoir to overflow; use a clean syringe to remove some fluid beforehand. The inner brake pad has a spring for location in the caliper piston, and the pad wear sensor should be carefully pried from the brake pad. Check caliper dust boots for damage and clean contact surfaces between the caliper and caliper carrier, applying a thin coating of anti-squeal compound to the caliper contact face and brake pad rests on the pad carrier, avoiding grease on the brake pad backing plate and ensuring the caliper rubber dust sleeve does not contact the anti-squeal compound. When installing directional brake pads, ensure marked pads are installed correctly, and if the brake pad wear sensor light was illuminated prior to replacement, replace the wear sensor. Route the pad wear sensor wiring through the caliper opening and under the bleeder dust cap, then follow the reverse order for installation, cleaning the brake caliper guide bolts and replacing any that are not in perfect condition without greasing them. Top off the brake fluid to the maximum marking, pump the brake pedal several times to ensure contact between the brake pads and rotors, check the brake fluid level, and top off if necessary, then hold the ignition key in the accessory position for at least 30 seconds to clear fault codes and turn off the brake pad warning light.
Posted by BMWPartsDeal Specialist 
