why does my Toyota Highlander Fourth Generation (2020-present) brake pedal feel soft and spongy

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface, and engage the parking brake.
• Wear safety glasses and gloves for protection.

2. Check and Refill Brake Fluid

• Locate the brake fluid reservoir under the hood.
• If the fluid is low, add the correct type of brake fluid (DOT 3 or DOT 4 as specified in the owner’s manual).
• Inspect the reservoir cap for proper sealing and replace if damaged.

3. Inspect and Replace Brake Lines

• Use a wrench to disconnect the brake lines from the master cylinder and calipers if leaks are found.
• Replace any damaged or corroded brake lines with new ones.
• Reattach the lines, ensuring they are secure and free from leaks.

4. Bleed the Brake System

• Begin at the furthest brake caliper from the master cylinder (usually the rear passenger side).
• Use a brake bleeder kit or two-person method to bleed each brake caliper:
  1. Have an assistant press the brake pedal several times and hold it down.
  2. Open the bleeder valve on the caliper until fluid flows out, then close it.
  3. Repeat until no air bubbles are visible in the fluid stream.
  4. Refill the reservoir as necessary during the process.
• Repeat for the remaining calipers (rear driver side, front passenger side, front driver side).

5. Reinspect and Test

• After bleeding, check the brake fluid level again.
• Start the vehicle and press the brake pedal to ensure it feels firm.
• Test drive the vehicle at low speeds to confirm proper brake function.