In vehicles equipped with drum brakes, the brake components are housed inside a drum that rotates with the wheel and axle. When you step on the brake pedal, brake shoes push out against the inside of the drum slowing the wheel. The brake drum is generally made of a special type of cast iron that is heat-conductive and wear-resistant. When a driver applies the brakes, the lining pushes radially against the inner surface of the drum, and the ensuing friction slows or stops rotation of the wheel and axle, and thus the vehicle.
At one time, passenger vehicles commonly employed drum brakes on all four wheels. Later, disc brakes were used for the front and drum brakes for the rear. However, disc brakes have shown better heat dissipation and greater resistance to 'fading' and are therefore generally safer than drum brakes. So four-wheel disc brakes have become increasingly popular, replacing drums on all but the most basic vehicles. Many two-wheel vehicle designs, however, continue to employ a drum brake for the rear wheel.
When brakes fade:
The pedal depresses farther (closer to the floor).
The distances it takes to stop increase dramatically.
The brakes emit a burning odor.
In the most extreme cases, the pedal can depress all the way to the floor without any braking action occurring the brakes can actually smoke or catch on fire. When brake fade happens, the only thing you can do is pull over and allow your brakes to cool and simply replacing the brake pads on a wheel with a bad rotor will not fix the problem but our ASE Master Certified Technician at Auto Repair Service can help you get it done right.