I have a 2005 madza 3 with anti-lock brakes. Just recently I noticed that when the brakes are put in a position where the "anti-lock" would come into play, I hear and feel a grinding noise under the car. The grinding feels like it's right under the brake pedal and when it grinds it tries to push back up on the pedal. If someone could help me diagnose what is going on it'd be greatly appreciated.