why is my Volkswagen Golf MK7 (2015-2019) brake pedal sinking to the floor

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is on a flat surface and secure it with wheel chocks.
• Wear safety glasses and gloves for protection.

2. Check and Refill Brake Fluid

• Open the hood and locate the brake fluid reservoir.
• Inspect the fluid level; if low, top off with the manufacturer-recommended brake fluid (DOT 4).
• Tools Required: None specifically for this step.

3. Inspect and Repair Leaks

• Visually check brake lines, hoses, and connections for any signs of leakage.
  • If a leak is found, replace the damaged line or hose.
  • Tighten any loose fittings.
• Tools Required: Wrench set, brake line flaring tool (if replacing lines).

4. Replace Master Cylinder (if needed)

• Disconnect the negative battery terminal to prevent electrical shorts.
• Remove the brake fluid reservoir cap and siphon out old fluid.
• Unbolt the master cylinder from the brake booster and disconnect the brake lines.
• Install the new master cylinder and reconnect the brake lines, ensuring they are properly tightened.
• Refill the brake system with new brake fluid.
• Tools Required: Socket set, line wrench.

5. Bleed the Brake System

• Starting from the wheel farthest from the master cylinder, use a brake bleeder kit or a helper to pump the brake pedal.
• Open the bleeder valve on each caliper one at a time while someone presses the brake pedal, allowing air to escape.
• Close the valve before releasing the pedal.
• Repeat until no air bubbles are present in the fluid.
• Tools Required: Brake bleeder kit, wrench.