Maintaining a smooth surface on the Mazda brake rotors and discs means your brake pads can last longer and be more effective in stopping your vehicle. It is this smooth surface that makes direct contact with the brake pads, and is where the friction and heat of this system is being generated. There are either two or four disc brake rotors on all Mazda vehicles. They are bolted to the wheel hub assemblies. The rear wheels may sometimes have the older drum style of braking system on them if the vehicle is a subcompact or older car. The brake rotors in the front also receive twice the amount of brake bias as the brakes in the rear because it is more efficient to stop the vehicle in the front rather than from the rear. Because of this brake bias, the front brake pads tend to wear out twice as fast as the pads or shoes in the rear. Located in the hub of the brake rotors are the wheel hubs and bearings. During a routine brake job on your Mazda, these bearings should have new grease applied to them as part of your vehicles routine maintenance. The only way damage can occur to the brake discs on your Mazda is when the brake pads wear out and are not replaced on time. When this occurs, the backing plate that the pads are mounted to comes in direct contact with the smooth surface of the rotors. This is a hard metal component that will cut grooves in the surface of the rotors. When this happens, the Mazda disc brake rotors will have to either be turned or replaced for your braking system to be restored to operational status.