What is the Difference Between Drum Brakes and Disc Brakes?
2 Answers
The main differences between drum brakes and disc brakes are as follows: 1. Different braking methods. Drum brakes use hydraulic pressure to push the brake shoes against the inner edge of the brake drum during braking, generating friction to inhibit the rotation of the tires and achieve braking. Disc brakes have flat brake pads on both sides of the brake disc. When hydraulic pressure from the master cylinder is delivered to the wheel cylinder, the brake pads clamp onto the brake disc to achieve braking. 2. Different components. Drum brakes consist of a brake backing plate, wheel cylinder, brake shoes, related linkages, springs, pins, and the brake drum. Disc brakes are hydraulically controlled, with main components including the brake disc, wheel cylinder, brake caliper, and hydraulic lines.
I often ponder about brake systems while driving. Drum brakes are that old-school design where the brake shoes are hidden inside the brake drum, and when you press the brake, they squeeze inward for friction braking. Disc brakes, on the other hand, use a brake disc with calipers clamping onto the rotor for direct external friction. The advantage of drum brakes is their strong braking force, especially stable when starting on slippery roads, and they're cheaper, so they're common in some economy cars. The downside is poor heat dissipation—after a few continuous presses, they overheat, reducing braking effectiveness, and they're prone to rust and water accumulation, requiring frequent maintenance. Disc brakes dissipate heat quickly and respond sensitively, with less fade during rainy conditions or long-distance driving, but their replacement parts are more expensive. Nowadays, disc brakes are mainstream, and I think they're much safer, especially on mountain roads or during sudden braking. When choosing, it depends on driving habits—drum brakes are sufficient for city commuting, but for highway driving, disc brakes are recommended.
