What’s Up With Those Old Drum Brakes?
Some people don’t just roll old school — they stop old school, too. Check the specs of some of the most reasonably-priced new cars and you’ll still find drum brakes listed instead of discs, usually on the rear wheels. What’s up with that?
Let’s Start With a Little History
Drum brakes first appeared on a car in 1900. And a couple of very prestigious names were involved along the way. The car sporting those first-gen drums was a Maybach (you might know that as the ultra-lux brand of Mercedes-Benz — and Karl Benz’s wife, Bertha, had invented brake pads 12 years before). Louis Renault patented the brake drum in 1902. His contribution, which allowed the patent, was to change the brake lining to asbestos, to dissipate heat (Bertha’s brake pads were leather). But the modern brake drum was a huge leap for the time — going from a primitive wooden brake to steel and springs that were much more reliable.
The Disc Brake Revolution
Cars pretty much stopped on drums for the next 50 years — until a trio of Jaguars won at Le Mans in 1953. They were equipped with disc brakes, which are less susceptible to fading over repeated use. That meant drivers could brake later going into turns, keeping a higher speed. Soon after, high-end performance cars (largely imports) began using disc brakes and, throughout the 1960s and 70s, more and more conventional domestic cars adopted them too.
Why Drum Brakes Survive
The biggest reason you will find drums on today’s vehicles is cost. It’s a simpler and cheaper design. Maintenance costs are less because drum brakes aren’t as easily corroded as discs. Their closed design keeps debris out, and since they’re most likely your rear brakes, they bear less of the job of stopping your car. A vehicle with discs up front and drums in the rear will probably go a lot longer without a rear brake job than one with discs on all four wheels. They’re also lighter than disc brakes and some hybrid manufacturers have found that having drums on the rear wheels reduce drag and wear from regenerative braking.
Drums also make a superior parking brake. The wedging action of the shoe against the drum is the reason. Once the brake is set, any attempt to move the wheel causes the drum brake to grip harder — kind of like a wedge-shaped doorstop.
Bottom line — if you’re looking at a new car or truck and you see rear drums on the equipment list, don’t worry. You’re not buying an antique. There are some good reasons for that choice, and from a maintenance standpoint, that can benefit you, too.
Check out all the brake system parts available on NAPA Online or trust one of our 17,000 NAPA AutoCare locations for routine maintenance and repairs. For more information on drum brakes, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.
Photo courtesy of Wikimedia Commons.