Which of the following is a disadvantage of drum brakes?

• A. More efficient in wet conditions
• B. Less prone to overheating
• C. More prone to overheating
• D. Less effective in dry conditions

Answer: (C)

Drum brakes are more prone to overheating due to their design and operational characteristics. When brakes are applied, the friction generated between the brake shoes and the inner surface of the drum produces heat. In drum brakes, this heat can accumulate because of the enclosed nature of the drum, making it less effective at dissipating heat compared to disc brakes, which are open to airflow. The risk of overheating leads to brake fade, where the braking performance diminishes as a result of elevated temperatures. This susceptibility makes drum brakes less reliable during extended or high-speed braking scenarios, especially in situations demanding consistent performance, such as on steep descents or during aggressive driving.

The other options contrast advantages of drum brakes over disc brakes, such as their performance in wet or dry conditions and their generally lower likelihood of overheating, which do not represent disadvantages of drum brake systems.