Genuine BMW 330i Brake Disc

BMW 330i Brake Disc Parts Questions & Answers

• Brake Disc, Ventilated
  34-21-6-855-004
  Q: How to replace brake discs and pads?

  A: If either disc requires replacement, it's essential to replace BOTH at the same time to ensure even and consistent braking. New Brake Pads should also be installed. Apply the parking brake, raise the front of the vehicle, support it on jackstands, and remove the appropriate front wheel. Inspect the disc surface for score marks and damage; light scratches are normal, but deep scoring may necessitate disc refinishing by an automotive machine shop. Ensure the disc isn't machined below its specified minimum thickness, which can be found stamped into the hub of the disc. If the disc is potentially warped, check it for runout using a dial indicator. Some professionals suggest resurfacing the discs during brake pad replacement for a smoother finish. Additionally, inspect the disc for cracks and wear. For removal, unscrew the bolts of the Brake Caliper mounting bracket, slide off the caliper assembly, and tie it to the front suspension coil spring. Mark the disc's relationship to the hub, remove the bolt securing the brake disc, and then remove the disc. For installation, ensure clean mating surfaces for the disc and hub, align marked points from removal, wipe any preservative coating from a new disc, position the caliper over the disc, and secure it. Finally, install the wheel, lower the vehicle, and depress the brake pedal a few times to ensure brake pads contact the disc. Check the brake operation before driving.
• Brake Disc, Ventilated
  34-21-6-855-004
  Q: How to inspect, removal, and install the brake disc on a BMW 330i?

  A: Firmly block the front wheels, then raise the rear of the vehicle and support it securely on jackstands. Remove the appropriate rear wheel. Release the parking brake. Inspect the disc. Removal: Remove the Brake Pads. Remove the bolts and remove the caliper mounting bracket. Discard the bolts; new ones must be installed. Loosen and remove the brake disc retaining bolt. It should now be possible to remove the brake disc from the stub axle by hand. If it is tight, lightly tap its rear face with a plastic mallet. If the Parking Brake Shoes are binding, check that the parking brake is fully released. Fully release the Parking Brake Cable tension to obtain maximum freeplay in the cable. Insert a screwdriver through one of the wheel bolt holes in the brake disc, and rotate the adjuster star wheel on the upper pivot to retract the shoes. The brake disc can then be removed. Installation: Ensure that the mating surfaces of the disc and hub are clean and flat. Align the marks made on removal, and tighten the disc retaining bolt to the specified torque. If a new disc has been installed, use solvent to wipe any anti-corrosion preservative coating from the disc before installing the caliper. Ensure the disc mounting surface on the hub is free from dirt and corrosion. Slide the caliper into position over the disc, making sure the pads slide pass either side of the disc. Tighten the caliper mounting bolts to the specified torque. Install the wheel, then lower the vehicle to the ground and tighten the wheel bolts to the specified torque. Adjust the parking-brake shoes and cable. Depress the brake pedal a few times to bring the brake pads into contact with the disc. Bleeding won't be necessary unless the brake hose is disconnected from the caliper. Check the operation of the brakes carefully before driving the vehicle. Recheck the parking brake.