Drum vs. Disc Brakes: What’s The Difference?

Car brakes have progressed far compared to the wooden block braking systems of old, becoming much safer and more efficient. In modern times, only two types of brakes see widespread use in roadgoing vehicles: drum and disc brakes. 

While both operate on similar principles and hydraulic assistance, both designs have pros and cons that make them the right choice for certain situations. In this article, we’ll go over how they work, the differences, and how they affect your driving experience!

Drum Brakes

Drum brake assembly
-WesK-, CC BY-SA 3.0 http://creativecommons.org/licenses/by-sa/3.0/, via Wikimedia Commons

Drum brakes were first introduced in 1902 yet remain extremely relevant today due to their inexpensive construction and tried-and-true design. 

These brake systems start with the drum, a concave housing attached to the wheel hub. On the inside wall of the drum sit brake shoes, which when pressed with the hydraulic force of the master cylinder, create friction against the rotating drum and slow down the vehicle. 

Despite extensive innovation in brakes and friction materials over the last century, drum brakes have remained a common choice for vehicle manufacturers looking for a cost-effective and trustworthy solution. Despite drum brakes’ slightly worse performance compared to their disc counterparts, the rear brakes of most new vehicles still employ drums. But why? 

Even with decreased braking performance, drum brakes still provide several benefits when used in certain vehicles. First off, they’re cheaper to produce and generally use less expensive manufacturing processes, which makes them appealing for commuter vehicles. Their larger contact area for friction allows them to have much better durability, and the closed design of the drum also protects against corrosion and road debris compared to open-faced discs. 

They aren’t perfect though, as drum brakes do present drawbacks that make them a suboptimal choice in some scenarios. As stated before, drum brakes have inferior braking performance. While this might not matter much for commuter vehicles primarily used for highway driving, luxury and performance-minded vehicles favor disc brakes for their use cases. 

Another downside is the thermal performance, as the concave shape doesn’t allow for the easy exit of hot air. This can lead to glazed brakes and reduced braking performance after aggressive or frequent braking. 

Disc Brakes

Modern disc brake setup

Invented around the same time as drum brakes, disc brakes didn’t see mainstream automotive use until the 50s. Since then, disc brakes have been the go-to for premium applications requiring high braking performance.

Disc brakes use a similar approach to creating friction as drum brakes with a few major differences in how it’s accomplished. Instead of pushing the brake shoe against the inside of a drum, disc brakes use hydraulic pressure from a caliper to push an abrasive brake pad against a large flat disc-shaped friction surface called a rotor. Disc brakes are better at producing friction, allowing them to stop the car quicker and with less braking force. 

Beyond just pure braking performance, disc brakes also solve some of drum brakes’ biggest drawbacks. For one, their large surface area and exposed friction surface allow for better heat dissipation to prevent overheating. These superior thermal properties allow for more aggressive and frequent braking without worrying about brake fade or glaze. The exposed nature of a disc brake setup also allows for quicker and less labor-intensive maintenance.

Even with these benefits, disc brakes are the less common choice for a reason. Disc brake setups are significantly more expensive to produce and maintain than drum brake setups, making them less practical for use in commuter vehicles and economy cars that don’t need the extra braking performance. 

The exposed nature of disc brake components compared to drum brakes also allows for increased wear and corrosion from weather, road salt, and debris. 

Brake Services at Lake City Auto Care

If you’re looking for brake services in Northern Idaho, trust the experts at Lake City Auto Care! We have locations in Coeur d’Alene, Rathdrum, and Hayden, all equipped with the training and experience to provide your vehicle with the highest level of service possible. Give us a call or schedule online with us today.

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