how to fix the brake pedal going to the floor in BMW 3 Series E90/E91 (2005-2012)?

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is on a flat surface and secure it with wheel chocks.
• Lift the vehicle using a jack and secure it with jack stands.

2. Check and Refill Brake Fluid

• Tools Required: Brake fluid, funnel
• Inspect the brake fluid reservoir; if low, refill it with the manufacturer's recommended brake fluid type (typically DOT 4).
• Inspect the cap for any cracks or damage before resealing.

3. Inspect and Repair Leaks

• Tools Required: Wrench set, brake line wrench
• Check all brake lines, hoses, and connections for leaks.
• If a leak is found, replace the damaged line or hose:
  • Use a line wrench to remove the damaged section.
  • Install the new line or hose, ensuring all connections are tight.

4. Bleed the Brake System

• Tools Required: Brake bleeder kit, clear tubing, container
• Start bleeding from the farthest wheel (usually the right rear):
  • Attach the clear tubing to the bleeder valve.
  • Open the valve slightly and have an assistant press the brake pedal.
  • Close the valve before the pedal reaches the floor, then release the pedal.
  • Repeat until no air bubbles are visible in the fluid.
• Move to the next wheel in the order: right rear, left rear, right front, left front.

5. Final Inspection

• After bleeding, check the brake fluid level again, and top off if necessary.
• Inspect all connections for leaks after the bleeding procedure.