What are the types of drum brakes?
2 Answers
Drum brakes can be classified into the following types: 1. According to the movement direction of the brake shoes, they can be divided into internal expanding type and external contracting type; 2. According to the braking device, they can be divided into wheel cylinder type brakes and cam type brakes; 3. According to the force acting on the brake shoes, they can be classified into leading-trailing shoe type, dual-leading shoe type (unidirectional action, bidirectional action), dual-trailing shoe type, and self-energizing type (unidirectional action, bidirectional action). 4. Extension: Drum brakes use the braking transmission mechanism to press the brake friction linings against the inner side of the brake drum, thereby generating braking force. This allows the wheels to decelerate as needed or stop within the shortest distance, ensuring driving safety and reliable parking without automatic slippage.
Having driven for a lifetime, I know a thing or two about drum brake types. The most common is the standard drum type, also called the twin leading shoe type, mostly used on the rear wheels of family cars—simple, cheap, but with average braking force. Then there's the duo-servo type, which offers stronger braking force when stopping, like those used in trucks or performance cars, providing stable parking. Modern cars often use self-adjusting drum brakes, which automatically adjust the gap to reduce faults, making them hassle-free. I've also seen the old self-servo type, which is rarely used now because it's troublesome to maintain. During maintenance, you need to check regularly based on the type, otherwise, the brakes may fail and cause accidents. Although drum brakes don’t dissipate heat as quickly as disc brakes, they are cost-effective and cheaper to replace. Just be careful not to brake hard on slippery roads when driving.
