Today, the Chevrolet disc brake pads are designed to last longer than pads made out of asbestos. This new composite material is made from either a ceramic or semi-metallic blend, is safe to work with, and has a higher friction coefficient that will make a positive contribution to your Chevrolets ability to stop when you need it to. There are two disc brake pads used in each caliper on your vehicle. They are a matching set and should not be interchanged with other pads. They are also used only on disc brakes. If your mechanic says he is replacing the disc brake pads on the rear of your Chevrolet which has drums brakes, question his experience. Drum brakes require shoes not pads as the replacement part that applies the friction to a surface. The Chevrolet disc brake pads on the front wheel of your vehicle have a tendency to wear out at a rate twice as fast as the pads or shoes in the rear. This is the result if the brake bias of the car. This setting applied nearly twice the force on the front wheels than the rears so the control of the car when stopping is better. There are two warning signs that it is time to replace the disc brake pads on your car. If the rear chamber in the brake master cylinder is low, the wear on the pads is extensive and an inspection of them is warranted. The extra travel of the piston in the caliper is the reason for the low fluid level. The other warning is a metal to metal grinding noise from the front of your car when the brakes are applied. This is when the disc brake pads on your Chevrolet have worn out and the metal backing plate is coming in contact with the rotors, damaging them.