Brake rotors are comprised of an iron disk connected to the hub of each wheel in a disc brake assembly. Typically, disc brakes are used on the front wheels of most vehicles, but increasingly manufacturers have been putting them on the back axels as well. Brake rotors work hand-in-hand with brake pads to provide stopping power for your vehicle. Brake rotors can last up to 70,000 miles or longer but should be checked often to avoid pitting or grooving from worn out brake pads.