my Acura MDX YF3 (2022-Present) rear brakes feel spongy what could be wrong

Symptoms

• Spongy or soft brake pedal feel
• Increased stopping distance
• Brake warning light may illuminate
• Possible fluid leakage around brake components
• Uneven brake application or pulling to one side during braking

Diagnostic Steps

1. Visual Inspection:

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

2. Fluid Level Check:

   • Open the hood and locate the brake fluid reservoir.
   • Check the brake fluid level; it should be between the "MIN" and "MAX" marks. Low fluid may indicate a leak.

3. Brake Fluid Quality:

   • Inspect the brake fluid for contamination or discoloration. Brake fluid should be clear to light amber. If it appears dark or cloudy, it may need to be changed.

4. Brake Pad and Rotor Inspection:

   • Remove the rear wheels using a socket set (typically a 19mm or 21mm socket).
   • Inspect the brake pads for wear; they should be at least 3mm thick.
   • Check the brake rotors for scoring, warping, or excessive wear.

5. Brake System Bleeding:

   • If no visible problems are found, proceed to bleed the brake system to eliminate any trapped air.

Repair Instructions

1. Gather Required Tools and Parts:

   • Tools: OBD-II scanner, socket set, brake bleeder kit, torque wrench, container for old fluid, and possibly new brake fluid (DOT 3 or DOT 4).
   • Parts: Brake fluid, brake pads (if worn), or brake rotors (if damaged).

2. Brake Fluid Replacement:

   • If the fluid is contaminated or low, replace it:
     • Remove the brake fluid reservoir cap.
     • Use a turkey baster to remove old fluid from the reservoir.
     • Fill with new brake fluid to the "MAX" line.

3. Bleeding the Brakes:

   • Attach a brake bleeder kit to the brake bleeder valve on the rear caliper.
   • Have an assistant pump the brake pedal several times and hold it down.
   • Open the bleeder valve to release air and fluid, then close it while your assistant holds the pedal down.
   • Repeat until no air bubbles appear in the fluid, and top off the reservoir as needed.
   • Repeat this process on both rear calipers.

4. Reassemble:

   • Reinstall the wheels and lower the vehicle.
   • Torque the lug nuts to the manufacturer’s specifications (typically 80-100 ft-lbs).

Estimated Time for Repair

• Approximately 1 to 2 hours, depending on the complexity of the brake system and any additional repairs needed.

Safety Warnings

• Always work on brakes with the vehicle securely lifted and supported on jack stands.
• Wear safety glasses and gloves when handling brake fluid, as it is corrosive and can damage paint and skin.
• Ensure the brake system is adequately bled before operating the vehicle to avoid brake failure.