My wife has an 02 ls sport cavalier with just over 100k on it. She has been complaining of having issues with her brakes, especially in the snow. I've experienced minor issues with them. She got all new brakes pads and even new rear shoes. The issue is this. In the snow, when she applies pressure to the brakes, they make this grinding noise like they lock up. My first thought was her ABS system kicking in, but the light or TRAC light never comes on in the dash. What could be causing this do this constantly driving in the snow? It doesn't matter if she's going downhill or just street level it always seems to happen. Also, whenever she comes to a complete stop at a stop sign or red light; whenever she releases the brake pedal there is a popping sound coming from somewhere. This also happens everytime you come to a stop and release the pedal. I am just confused as to what it could be. Any suggestions?

the light will not come on when ABS is active, only when there is a problem keeping the system from operating properly.......sounds like the ABS working is your first complaint. And the second, I would say is in the shoes. A lot of people have noise problems similar to this when they buy non-GM brake shoes.