Illinois CDL Practice Exam 2025 - Free CDL Practice Questions and Study Guide

The component of air brakes that is connected to the engine through gears or a V-belt to pump air into the air storage tanks is the air compressor. This device plays a crucial role in the air brake system by converting mechanical energy from the engine into compressed air. The air compressor takes in atmospheric air and compresses it, then delivers it to the storage tanks where it is held until needed for braking.

By having this connection to the engine, the air compressor can function continuously while the vehicle is running, ensuring that air is available for braking and other systems that require compressed air. The efficiency and reliability of the air brake system largely depend on the proper functioning of the air compressor.

In contrast, the air compressor governor, alcohol evaporator, and air storage tanks serve different purposes within the air brake system. The governor regulates the air pressure in the system, the alcohol evaporator helps prevent moisture in the air system, and the storage tanks hold the compressed air but do not have a role in pumping it.