my BMW 3 Series shakes when I brake what could be causing this

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and engage the parking brake.

2. Wheel Removal

• Loosen the lug nuts slightly while the vehicle is still on the ground.
• Jack up the vehicle and securely place it on jack stands.
• Remove the lug nuts and take off the wheel.

3. Brake Inspection

• Inspect Rotors:
  • Check rotors for warping using a dial indicator.
  • If warped beyond service limits (typically over 0.002 inches), replace rotors.
• Inspect Brake Pads:
  • Check for uneven wear and ensure they have sufficient material.
  • Replace any worn or uneven pads.
• Inspect Calipers:
  • Ensure calipers move freely and are not stuck.
  • Lubricate guide pins if necessary.

4. Rotor Resurfacing or Replacement

• If rotors are within specifications, consider resurfacing them to eliminate minor warping.
• If replacing, install new rotors according to manufacturer specifications (typically torque to 90-100 ft-lbs).

5. Reassembly

• Reinstall the brake pads onto the caliper.
• Reattach the wheel and hand-tighten the lug nuts.
• Lower the vehicle and torque lug nuts to specifications (typically 80-100 ft-lbs).

6. Testing

• Start the vehicle and gently test the brakes at low speed to ensure proper function and to check for any vibrations.

Tools Required:

• Jack and jack stands
• Lug wrench
• Torque wrench
• Dial indicator
• Brake cleaner
• Lubricant for caliper pins

Parts Required:

• Brake rotors (if warped beyond limits)
• Brake pads (if worn)

Estimated Repair Time: 2-4 hours

Safety Warnings:

• Always wear safety glasses when working on brakes.
• Ensure the vehicle is securely supported before working underneath it.