Disc vs. Drum Brakes - Understand How They Work and Which Are Better

Disc vs. Drum Brakes - Understand How They Work and Which Are Better

Drum Breaks?

Drum brakes are a small round drum that has a set of shoes inside of it. The drum brake will rotate alongside the wheel and when the brake pedal is applied, the shoes are forced against the sides of the drum and the wheel is slowed. 

Disc Breaks?

A disc brake has a disc shaped metal rotor spinning within a wheel. When pressure is applied to the brake pedal a caliper will squeeze the brake pads against the disc. This will slow the wheel down as more pressure is applied to the brake pedal, bringing the car to a halt.


Disc brakes are generally considered superior to drum brakes for several reasons. First, disc breaks do a better job dissipating heat. Under severe use, such as repeated hard stops or riding the brakes down a long incline, disc brakes take longer than drum brakes to lose effectiveness, which is a condition known as "brake fade." Disc brakes also perform better in wet weather, because centrifugal force tends to fling water off the brake disc and keep it dry, whereas drum brakes will collect some water on the inside surface where the brake shoes contact the drums.

If Disc Brakes are more popular why are cars and trunks still using drum breaks?

Braking causes the cars weight to shift forward; as a result, about 70% of the work is done by the front brakes. Thats why your front brakes tend to wear out faster. Drum brakes are less expensive to make than disc brakes, largely because they can also double as a parking brake, whereas disc brakes require a separate parking brake mechanism. By fitting disc brakes to the front wheels and drum brakes to the rear wheels, manufacturers can provide most of the benefits of disc brakes while lowering costs.

Publisher: Mechanics At Work
Date Published: Nov 2 2017 12:30PM
Date Edited: Oct 8 2018 12:00PM