About Brake Rotors

The ability to rapidly bring your car to a stop in a controlled manner is one of the most important safety features on any vehicle. At the turn of the last century, most cars used a system of hand levers to apply friction to the wheel in order slow down and stop. Today, most automobiles manufactured in the United States rely on the disc braking system that is composed of a brake rotor, a caliper and a brake pad.

History

The disc braking system is not a new invention. Frederick Lanchester patented the first such device shortly after the turn of the 20th Century. Drum brakes remained state of the art for the auto industry however, for the next 50 years. High performance vehicles started using brake rotor technology in the 1950s, but it wasn't until the 1970s that the use of front disc brakes became widespread on American cars. Today most cars come with standard front disc brakes and many use brake rotors on all four wheels.

Significance

The ascendancy of disc brakes over other types of braking systems can be attributed to one single factor-safety. Since most of the stopping power in any vehicle is provided by the front wheels, the front disc braking system was the first brake rotor system to be adopted by US auto manufacturers. Because disc brakes use a rotor that is exposed to the outside air, they do not build up heat to the same extent as drum brakes, significantly reducing the likelihood of the brakes fading or even failing due to overheating.

Features

All braking systems operate by applying friction to the wheels causing them to slow down and eventually stop. Disc brakes use a system which forces fluid into the caliper causing it to expand, which in turn forces the brake pads on either side of the rotor to contract against the brake rotor creating friction which slows and stops the vehicle. While some brake rotors may be made of solid cast iron, most are composed of space age metal alloys and vented to allow for rapid heat dissipation.

Benefits

The most common disc brake design used on modern American cars is the single-piston floating caliper. The rotors on these brake systems quickly and efficiently dispel heat providing a safer driving experience, particularly in high stress situations, such as long downhill grades or emergency braking events. In addition to being vastly superior to drum brakes in stopping power, these brakes are also much easier and less expensive to service; with proper maintenance brake rotors should never have to be replaced.

Prevention/Solution

Disc braking systems rely on brake pads to apply friction against the brake rotor to slow and eventually stop the car. This friction creates brake dust than can accumulate on the rotor or in the caliper. Regularly spraying the wheels when you wash your car will help to remove brake dust from your rotors. Rotors may also be scarred if the pads are allowed to wear down too far before they are replaced. It may be possible for a machine shop to resurface the rotors, but if they are badly scarred they should be replaced.