why does my Acura MDX YF3 (2022-Present) brake pedal feel spongy

Symptoms

• Spongy or soft brake pedal feel when pressed
• Longer stopping distances
• Brake warning light illumination on the dashboard (if applicable)
• Possible fluid leaks under the vehicle near the brake components

Diagnostic Steps

1. Visual Inspection:

   • Check for any visible brake fluid leaks around the master cylinder, brake lines, and calipers.
   • Inspect the condition of the brake lines for any signs of wear or damage.

2. Check Brake Fluid Level:

   • Open the hood and locate the brake fluid reservoir. Ensure the brake fluid is at the recommended level. Low fluid levels can lead to a spongy pedal.

3. Scan for Error Codes:

   • Use an OBD-II scanner to check for any brake-related error codes that might indicate a malfunction in the braking system.

4. Brake System Bleed Test:

   • Check if air has entered the brake lines by performing a brake bleed test. Air in the system can cause a spongy pedal feel.

5. Master Cylinder Inspection:

   • Inspect the master cylinder for any signs of internal failure. A failing master cylinder can lead to a spongy brake pedal.

Repair Instructions

Tools Required

• OBD-II scanner
• Brake fluid
• Brake bleeder kit or clear tubing
• Wrench set
• Torque wrench
• Socket set
• Safety goggles and gloves

Steps to Repair

1. Check Fluid Level:

   • If the brake fluid is low, top it off with the manufacturer-recommended brake fluid (DOT 3 or DOT 4, depending on your vehicle). Ensure the reservoir cap is secured after filling.

2. Bleed the Brake System:

   • If air is present in the brake lines, bleed the brakes using the following steps:
     • Start at the furthest brake from the master cylinder (usually the passenger rear brake).
     • Attach the brake bleeder kit to the bleeder valve on the brake caliper.
     • Have an assistant press the brake pedal down slowly while you open the bleeder valve to release air and old fluid.
     • Close the valve before your assistant releases the brake pedal.
     • Repeat until you see a steady stream of brake fluid without bubbles.
     • Move to the next brake in sequence (passenger front, driver rear, driver front).

3. Inspect and Replace Components if Necessary:

   • If bleeding does not resolve the issue, inspect the master cylinder. If defective, it may need to be replaced.
   • Check brake pads and rotors for wear. Replace if they are below recommended thickness.

4. Check Brake Lines:

   • Inspect all brake lines for corrosion or damage. Replace any damaged lines.

5. Recheck Brake Fluid Level:

   • After bleeding, ensure the brake fluid level is at the appropriate level.

6. Test Drive:

   • Once repairs are complete, conduct a test drive to ensure the brake pedal feels firm and responsive.

Safety Warnings

• Always wear safety goggles and gloves when working on brake systems to protect against brake fluid, which can damage skin and paint.
• Ensure the vehicle is securely lifted and supported when working under it.
• If you are unsure about any step, consult a professional mechanic.