Which type of brake system typically requires maintenance due to wear of brake pads?

The correct choice highlights a brake system that often necessitates regular maintenance because of the wear of its brake pads. Disc brakes are designed with a system where the brake pads clamp onto a rotating disc or rotor to create friction, which slows down or stops the vehicle. Over time, as the brake pads undergo repeated friction from this process, they naturally wear down. This wear requires monitoring and eventually replacing the pads to ensure optimal braking performance and safety. Regularly inspecting disc brakes is critical, as worn pads can lead to decreased braking efficiency and can even cause damage to the rotor if not addressed. In contrast, other brake types, such as drum brakes also experience pad wear, but the mechanism is different and may not be as prominent in maintenance discussions. Electric and pneumatic brakes function using different principles, focusing more on electrical systems or air pressure, which do not inherently rely on frictional wear of pads in the same way.