What is the role of brake shoes in a braking system?

The role of brake shoes in a braking system is fundamentally about creating friction to slow down or stop the vehicle. When the driver applies the brakes, hydraulic pressure causes the brake shoes to expand and press against the interior surface of the brake drum. This friction generated between the brake shoes and the drum is what slows the vehicle down. The material of the brake shoes is typically designed to withstand high temperatures and wear, ensuring effective braking performance over time.

In contrast, the other roles mentioned do not pertain to the function of brake shoes. For instance, communicating with the driver, assisting in automatic braking, or holding brake fluid are tasks associated with different components of the braking system. Therefore, understanding that the primary function of brake shoes is to create friction through contact with the drum is key to grasping their importance in effective braking.