WHY WHEN I PUSH MY BRAKES ON BUMPS IN THE ROAD, I HAVE TO PRESS EVEN HARDER TO STOP AND THEY MAKE A GRINDING NOISE?
BRAKE PROBLEMS on 2005 Pontiac Grand Prix
That "grinding" noise may be your Anti-Lock Brake system comming on. When you apply the brakes going over bumps it is very easy to engange the ABS and with the ABS active it feels like you must press even harder to stop. To confirm this try engaging your ABS on a smooth service. Find an empty parking lot. Whith your seat belt secure slam on the brakes from about 30mph. You should feel the ABS engage and that should be the same sound as you hear over the bumps.