why does my Toyota Highlander Fourth Generation (2020-present) brake pedal feel spongy and goes to t...

Solution

1. Preparation

• Gather tools: socket set, brake line wrenches, brake fluid, OBD-II scanner, vacuum pump.
• Ensure the vehicle is on a level surface and the parking brake is engaged.
• Wear safety gloves and goggles.

2. Check and Refill Brake Fluid

• Locate the brake master cylinder reservoir.
• Open the cap and check the brake fluid level.
• If low, add the appropriate brake fluid (DOT 3 or DOT 4 as specified in the owner’s manual) to the recommended level.
• Secure the cap back on the reservoir.

3. Inspect Brake Lines for Leaks

• Visually inspect all brake lines, hoses, and connections for any signs of fluid leaks.
• If leaks are found, replace the affected brake lines or hoses using the following steps:
  • Use a brake line wrench to disconnect the line at the master cylinder and brake calipers.
  • Install new brake lines ensuring they are properly secured and oriented.
  • Bleed the brake system after installation to remove air.

4. Bleed the Brake System

• Attach a brake bleeder kit to the brake bleeder valve on the furthest brake caliper from the master cylinder.
• Have an assistant pump the brake pedal several times and hold it down.
• Open the bleeder valve to release air and fluid, then close the valve while your assistant holds the pedal down.
• Repeat until no air bubbles are observed in the fluid.
• Move to the next caliper and repeat the process until all calipers have been bled.

5. Inspect and Replace Brake Pads (if necessary)

• Remove the wheel and caliper to access the brake pads.
• Check the thickness of the brake pads; if they are worn below manufacturer specifications, replace them.
• Reinstall the caliper and wheel after ensuring everything is secure.