my BMW X3 F25 (2011-2018) brakes feel spongy, what should I do

Solution

1. Preparation

• Gather tools and parts needed.
• Ensure the vehicle is on a flat surface and securely lifted using jack stands.
• Wear safety goggles and gloves.

2. Inspect and Top Off Brake Fluid

• Tools Required: Brake fluid, funnel
• Check the brake fluid level in the master cylinder reservoir. If low, top off with the manufacturer-recommended brake fluid.
• Inspect the reservoir for cracks or damage.

3. Inspect Brake Lines and Components

• Tools Required: Wrench set, flashlight
• Visually inspect brake lines, hoses, and connections for any signs of leakage or damage.
• Tighten any loose connections and replace any damaged lines or hoses.

4. Bleed the Brake System

• Tools Required: Brake bleeder kit, clear tubing, container
• Start by removing the wheel for access to the brake calipers.
• Attach the clear tubing to the bleeder valve on the caliper.
• Have an assistant pump the brake pedal several times, then hold it down.
• Open the bleeder valve to release air and fluid, then close it before the pedal is released.
• Repeat this process until no air bubbles are visible in the tubing, starting from the furthest brake from the master cylinder to the closest.
• Recheck brake fluid levels during the process and top off as necessary.

5. Test the Brake Master Cylinder

• Tools Required: Brake master cylinder tester (if applicable)
• If sponginess persists after bleeding, test the master cylinder for proper operation.
• Check for any signs of internal failure or leakage and replace if necessary.