Expendable Components Produce Continual Repairs
Since the invention of the automobile, brake linings have always been considered an expendable component. Not, perhaps, as expendable as the gasoline that propels the vehicle, but expendable nonetheless. Brake linings are sacrificial components designed to convert kinetic energy into heat energy by rubbing against a rotating brake rotor or drum. This rubbing action or friction wears away a miniscule portion of the brake lining and rotor or drum each time the brake pedal is applied.

The brake actuating system, consisting of the master cylinder, calipers, hoses and wheel cylinders, also experiences wear each time the driver applies the brakes. Some drivers rarely use their brakes and therefore never wear out a set of brake linings. Nevertheless, no matter how little the brakes are used, moisture contamination and rust will eventually cause the brake actuating system to fail.

Although brake systems wear at a relatively glacial rate, a point will be reached when they can no longer stop the vehicle in an emergency situation and brake system inspections are therefore required to prevent accidents caused by brake component failure. Inspection procedures vary from area to area. Mountainous or metro-area driving conditions, for example, obviously demand more brake performance than do plains-area conditions.

INSPECTION STANDARDS
States requiring periodic safety inspectio...