Precautions for Installing Automobile Brake Discs: Do Not Overlook These Details

Before replacing the brake discs, the vehicle must be parked on a flat and secure surface, with the handbrake engaged and the vehicle firmly supported by a jack. Prior to disassembly, thoroughly inspect the condition of the brake calipers, brake pads, and brake hoses to ensure there is no damage or excessive wear. Additionally, always verify that the model, dimensions, and material of the new brake discs perfectly match the original equipment specifications to prevent any reduction in braking performance due to incompatible parts.

Thorough Cleaning of the Mounting Surface

After removing the old brake discs, the contact surfaces between the wheel hub and the brake discs are often covered with rust, dust, or oil. If not cleaned properly, an uneven mounting surface will cause uneven stress distribution on the new brake discs, potentially leading to brake judder during driving. Therefore, it is essential to use specialized cleaners along with fine sandpaper or a wire brush to thoroughly grind and clean the hub mounting surface, ensuring it is completely flat and smooth.

Directional Markings and Installation Details

When installing new brake discs, pay special attention to the installation direction. Some brake discs feature an arrow marking on the surface, which must point in the normal direction of wheel rotation. Furthermore, for ventilated brake discs, ensure the direction of the internal ventilation channels is correct. Align the brake disc with the bearing hole and tap it gently into place, making sure it sits flush against the hub without any tilting or looseness.

Caliper Maintenance and Torque Specifications

Before installing the brake caliper, clear any rust from the caliper bracket sliding grooves and apply high-temperature resistant grease to the guide pins to ensure smooth caliper retraction. Use specialized tools to push the caliper piston back into place smoothly. When tightening the bolts for the brake discs and calipers, never rely on a "feel" approach. You must use a torque wrench and strictly follow the torque specifications outlined in the vehicle's repair manual. This prevents bolt fracture from overtightening or safety hazards caused by loose bolts.

Special Handling for Electronic Parking Brakes

For vehicles equipped with an Electronic Parking Brake (EPB), you must use a professional diagnostic scanner to access the vehicle system and execute the "release electronic parking brake" function to retract the rear wheel cylinder piston before removing the rear brake discs. Never force or pry the components apart, as this may damage the EPB motor. After the replacement is complete, use the scanner to reactivate and recalibrate the EPB system.

Brake Bleeding and Break-in Testing

After replacing the brake discs, air may enter the brake lines because the caliper pistons have been compressed. At this point, check the brake fluid level and perform a brake bleeding procedure. Once the tires are reinstalled and the vehicle is lowered to the ground, do not drive immediately. Instead, pump the brake pedal several times in place until the pedal regains its normal resistance and travel. New brake discs require a break-in period of approximately 1,000 kilometers. During this time, avoid sudden braking and aggressive driving to allow the brake discs and pads to mate perfectly.