Why do my brakes squeak? There could be many reasons why your brakes would squeak. The composition of the brake pad on your car could have abrasives in it which could cause it to make noise when there is contact with the brake rotor. Your brake pads also come with anti-rattle clips that could cause brake noise. One of the most common brake squeal complaints is when the brake rotor surface builds up rust from sitting. If your brakes are squeaking, the best way to discover the cause is to have your brakes inspected by a qualified mechanic.