What is the Service Brake?

The service brake in an automobile is the primary braking system. This brake is typically operated by foot and is mechanically separated from the parking brake or emergency braking system. The service brake can be comprised of disk or drum brakes or a combination of the two. This system is typically hydraulic and relies on hydraulic pressure to activate the braking system.

The typical service brake uses a bias with most of the braking force being applied to the front brakes. This allows the vehicle to remain in control under heavy braking applications. On vehicles with too much rear brake bias, the vehicle will slide out of control under heavy braking conditions. The same thing will happen to a vehicle with too much front brake bias.

Proper maintenance is required to keep the service brake in peak operating order. Heat from braking can cause the disk-brake rotor to warp, resulting in a noticeable pulse in the brake pedal when braking hard. Drum brakes are also the victim of heat, and the brake drum can become egg-shaped and out-of-round. This can often be corrected in both circumstances by having the rotors and drums machined or turned by a professional.

Perhaps the most difficult job of any automobile component falls into the capable hands of the service brake. Bringing a vehicle down from speed and even stopping a moving vehicle is an extremely difficult task. The vehicle's braking system typically performs this duty hundreds of thousands of times in an average year.

While taken for granted most of the time, a properly working braking system is bound to need some preventative maintenance to ensure it remains in tip-top order. Replacing brake pads at the first hint of brake noise is important. Also, an automobile owner should follow the manufacturer's recommended time table for brake maintenance and/or replacement. Always service the drums and rotors when replacing brake shoes and pads. Proper maintenance will keep any vehicle's service brake in peak operating condition.

When performing routine maintenance on the service brake, do not neglect the brake fluid. Brake fluid attracts moisture, which can cause damage to the brake components as well as catastrophic brake failure. It also is subjected to extreme heat and can burn. Flush the brake lines and replace the brake fluid according to the manufacturer's recommended time table. When having brake service performed, ask about the condition of the brake fluid. Have the fluid replaced at the first sign of water or if the fluid smells burnt.