why does my BMW 3 Series E90/E91 have a grinding noise when I brake?

Solution

1. Preparation

• Gather tools and parts.
• Ensure the vehicle is parked on a level surface and secure it with wheel chocks.
• Disconnect the battery to prevent electrical issues while working on the brakes.

2. Remove Wheel

• Use a lug wrench to loosen the lug nuts.
• Raise the vehicle with a jack and secure it on jack stands.
• Remove the lug nuts and take off the wheel to access the brake components.

3. Inspect and Replace Brake Pads

• Remove the caliper bolts using a socket set.
• Carefully lift the caliper off the rotor and support it with a bungee cord or similar tool to avoid stressing the brake line.
• Remove the old brake pads from the caliper bracket.
• Inspect the brake pad backing plates for wear—replace if necessary.
• Install new brake pads, ensuring they are oriented correctly.

4. Inspect and Replace Brake Rotors (if necessary)

• Check the rotors for grooves or warping.
• If damaged, remove the rotor by unscrewing the retaining screws (if applicable) and sliding it off the hub.
• Clean the hub surface where the new rotor will sit.
• Install new rotors, ensuring they are properly aligned.

5. Reassemble Brake Components

• Reattach the caliper over the new brake pads and rotor.
• Tighten the caliper bolts to the manufacturer’s specified torque value (typically around 25-30 Nm for BMW).
• Reinstall the wheel and tighten the lug nuts in a crisscross pattern.

6. Final Checks

• Reconnect the battery.
• Pump the brake pedal several times to seat the new pads and check for proper brake operation.