How Can I Change X3 Brakes?

All-wheel anti-lock brakes is a factory feature of BMW X3. When brake pads reach a level of wear worthy of replacement (Brake pads are fitted with wear indicators), they will scrape against the rotors. This scraping can score the rotors’ surface, requiring replacement for the discs as well. You can either have the BMW’s brakes changed by a professional mechanic or perform the task yourself.
Things You’ll Need
Turkey baster or syringe
Shop rag
Lug wrench
Jack stands
12 mm socket
Bungee cord
Flat screwdriver (optional)
Brake parts cleaner
Wire brush
Cloth towel
Brake rotor
Brake pads
Channel-lock pliers
Brake fluid
1. Park the BMW on level ground and turn off the engine. Apply the parking brake and pull the hood release lever. Move to the front of the X3 and lift the hood.
2. Remove the master cylinder cap located on the left side of the engine. Siphon half of the brake fluid from the reservoir with a turkey baster or syringe. Place a shop rag over the master cylinder to keep debris from getting into the remaining fluid.
3. Loosen the lug nuts with the lug wrench. Lift the vehicle with the lifting jack and rest the frame on at least two jack stands, leaving the tires at least 3 inches from the ground. Remove the lug nuts and take the wheels off.
4. Remove the two caliper slide pins with a 12 mm socket and ratchet. The pins are located on the top side of the inward facing side of the caliper. Lift the caliper from the rotor.
5. Slide the two brake pads from the sides of the caliper. Pry the metal clips on the back of the pads if you are unable to easily slide them free by hand. Suspend the caliper above the wheel with a bungee cord to alleviate stress on the attached brake line.
6. Pull the rotor from the wheel hub. Strike the center section of the disc with a hammer to break the bond of rust that may make rotor removal difficult. Clean the steering knuckle (behind the rotor) with a wire brush and brake cleaner if rust is present.
7. Clean the new brake rotor with a towel and brake parts cleaner to remove the packing oils. Place the new rotor onto the wheel bolts. Push it against the steering knuckle.
8. Force the caliper pistons into the side of the caliper. The pistons are responsible for forcing the brake pads against the rotor during braking. Place a spent pad across both pistons and squeeze the pistons into the side of the caliper with a pair of channel-lock pliers. Remove the pad and pliers once both pistons are fully depressed within the side of the caliper.
9. Apply copper-based anti-squeal brake grease to the back of the new brake pads. Slide the pads onto the sides of the caliper and replace the caliper over the rotor.
10. Replace the caliper slide pins with the socket and ratchet.
11. Replace the wheel onto the wheel bolts. Repeat steps 4 through 10 for each additional brake that requires replacement.
12. Move to the driver’s seat. Start the X3’s engine and depress the brake pedal three times slowly to reset the caliper pistons. Turn off the engine and return to the engine compartment.
13. Remove the shop rag from the master cylinder and insert a funnel. Add brake fluid to the reservoir until it is full. Remove the funnel and secure the master cylinder cap back onto the container. Close the BMW’s hood.