Acura 46400-S03-Z01 Power Assembly, Master (7"+8")

To test brake booster operation, depress the brake pedal multiple times with the engine off, then start the engine with the pedal depressed; if it goes down slightly, it's normal. Check airtightness by starting the engine, turning it off, and depressing the brake pedal slowly. If the pedal gradually rises after initial depression, the booster is airtight. To remove, take off the brake master cylinder, disconnect the hose from the engine to the booster, remove the cotter pin and clevis pin, and remove the four nuts holding the booster. Install a new booster by adjusting the input rod length, ensuring tight mounting nuts and a new cotter pin. After installation, bleed the brakes.

To check the brake booster: Start the engine with the brake fully depressed, and the pedal should move down slightly. Depress the brake pedal several times, and the travel distance should not change. Stop the engine and hold the pedal in for about 30 seconds; the pedal should neither sink nor rise. Restart the engine, run it for about a minute, and firmly depress the brake several times; the pedal travel should decrease with each application. If the brakes do not operate as described, the brake booster has failed.