The modern day brake system of today's cars has come a long way from the old systems attached to cars in the past. With all of the advances that have come to be a regular part of automobiles today total brake failures are a rare thing but they still happen. It is for this reason that one of the most important areas of automotive service is regular brake service. The modern brake system consists of a few basic parts and, with anti-lock brake systems becoming more common, a computer controller. Some of these basic parts include the vacuum brake booster, the master cylinder, the brake lines, the ABS control unit for cars and trucks with ABS, calipers, pads, wheel cylinders in cars and trucks with rear drum brakes, rotors and wheel speed sensors for cars and trucks with ABS.

With all of these advanced components comes a greater need for more frequent automotive service. Luckily automotive manufacturers have built in a few methods for alerting the attentive driver to a need for service. Some of these early warning features built into the brake system can be quite visible.

One example of such a visible warning is the red brake warning light. This light is usually located in the instrument panel where the speedometer is located and can be on for multiple problems. The light will come on when brake fluid has dropped to a level that might indicate a leak or worn out pads. As the brake pads wear down, they start to move closer to the rotor. This will often cause the brake fluid level to drop down and turn on the red brake warning light. This lets the driver know that it is time to take the car to an auto repair center to have the brake system looked at. Another early warning system is the ABS warning lamp. This lamp will turn on when the computer that controls the ABS system has detected a fault with the ABS system. ABS works by monitoring the speed of the car or trucks wheels. When the system detects a difference in speed that could indicate the wheels slipping on a slick surface such as ice or water it will rapidly turn the brake that is on the slick surface on and off to prevent wheel lock up. This allows the driver to maintain steering during a slip and decreases stopping distance during a slip. The warning light will turn on during situations ranging from a defective wheel speed sensor to low brake fluid.

There are also less obvious warnings to brake problems. One of these is the so called squeaker. This is a piece of metal on the brake pads that causes a squealing sound as the pads reach a level low enough to require service. All of these warning systems are designed to warn the driver that car service is necessary before major problems show up, and should be looked for before major grinding or other problems show up.