About Car Brakes

Car brakes are one of the most important safety features on your vehicle. Every day, you press the brake pedal hundreds of times to stop a car that weighs as much as 2 tons. With every press of the brake pedal, you engage a complex system that sends your instinctive movement from the pedal to the brakes located at each wheel. Maintaining your brakes requires good knowledge of the entire braking system on your vehicle.

Features

Brake systems have a number of parts that require regular maintenance for safety and optimum performance. Located under the hood of your car is the brake fluid container that holds extra brake fluid. The master cylinder functions as a brake fluid reservoir connected by lines to the brake pedal system and forces brake fluid into the brake lines. Brake lines are strong rubber hoses that connect the master cylinder to the brake system on each wheel.

Brake pads (also called brake shoes) are roughly 1/4-inch-thick, oblong pads made of copper, brass or steel. Pads are attached to a caliper that compresses to drop the rotating disc or drum on a wheel. Drum brakes are located on the rear wheels of the car; disc brakes are located on the front. Brake pads press against both drums and discs to stop the vehicle. Rotors are the circular part of the disc brakes that are gripped by the pads for stopping the car. Consistent pressure against the rotor can cause grooving that may require smoothing (by grinding) during maintenance.

Types

Drum brakes are typically found on the rear wheels of a car. Drum brakes work by forcing a piston to compress two brake shoes against the drum when you push the brake pedal. Disc brakes are found on the front wheels. Disc brakes can also be found on rear brakes. They function by allowing the brake pads to squeeze the rotor instead of the wheel (like a bike does). This force is transmitted through a cable, and the resulting friction slows the disc's rotation.

Other braking systems on the car include the emergency brake, which is controlled through a series of steel cables. Another system is called the anti-lock braking system. This computerized system can be found on newer vehicles. ABS automatically applies the brakes at the point of wheel lockup when you start to skid. So instead of pumping the brakes when you lose traction, the computer does it for you.

Function

There are many component parts to the braking systems on newer-model cars. To begin, when you press the pedal, pressure transfers from the pedal to the master cylinder. The master cylinder forces brake fluids into the brake lines that connect to each wheel of the car. The fluid moves through the line, creating friction. This friction creates heat that reaches the brake pads or drums/disc brakes. The heat caused by the friction causes the compression of the brake pads against the brake drum or disc, which stops the forward motion of the car.

Considerations

Regular maintenance of your entire braking system is a must. For safety reasons, you should have your brake system safety inspected at least once a year. Your brake system should be serviced at least every 2 years. This service should include replacement of front brake pads if necessary, resurfacing of the rotors, replacing disc or drum brake pads, bleeding of the entire brake system, replacing brake fluid, and a total inspection of the brake system. In general, your car's brake system should be serviced every 20,000 to 30,000 miles.

Warning

There are rather distinct signs that your brakes need attention. However, there isn't always a warning that your brakes might be failing, and it's dangerous to wait until too late. Some of the signs of excessive brake wear include a squealing sound, caused when the brake pads have worn to their replacement indicators, vibrations when pressing the brake pedal, and the dashboard brake warning indicator light. Your brakes might also need service if you notice the steering wheel pulling to one side, or if your brake pedal feels spongy or hard to push.