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

Solution

1. Preparation

• Gather necessary tools and parts.
• Park the vehicle on a level surface and engage the parking brake.
• Wear safety glasses and gloves.

2. Check and Refill Brake Fluid

• Sub-steps:
  1. Open the hood and locate the brake fluid reservoir.
  2. Check the fluid level; if low, top off with the recommended brake fluid (DOT 3 or DOT 4).
  3. Inspect the reservoir cap for proper sealing.

3. Inspect Brake Lines and Components

• Sub-steps:
  1. Conduct a thorough visual inspection of brake lines for cracks, corrosion, or leaks.
  2. Examine brake calipers for signs of leakage or damage.
  3. If leaks are found, replace the damaged line or caliper.

4. Bleed Brake System

• Sub-steps:
  1. Start at the brake furthest from the master cylinder (usually the right rear).
  2. Attach a clear tube to the bleeder valve and place the other end in a container.
  3. Have an assistant press the brake pedal while you open the bleeder valve to release air and fluid.
  4. Repeat for all four wheels, ensuring the fluid runs clear without bubbles.
  5. Recheck brake fluid level and top off if necessary.

5. Inspect and Replace Brake Pads and Rotors (if needed)

• Sub-steps:
  1. Remove the wheel to access the brake assembly.
  2. Measure the thickness of the brake pads; replace if below the manufacturer's minimum specification (usually 3mm).
  3. Inspect the rotors for warping or scoring; replace if necessary.
  4. Reassemble all components, ensuring proper torque specifications (typically around 80-100 ft-lbs for wheel lug nuts).