Louisiana Class D Chauffeur's License Practice Test 2026 – Complete Exam Prep

The air compressor is a critical component of the air brake system because it is responsible for pumping air into the storage tanks. When the vehicle's engine is running, the air compressor generates compressed air, which is then stored in the air storage tanks. This stored air is essential for the operation of the air brake system, as it allows for the activation of the brakes when needed.

The air compressor works in conjunction with other parts of the brake system. For example, the air compressor governor controls the pressure within the system by regulating the compressor's operation, but it does not pump air itself; rather, it manages when the air compressor operates. Therefore, while it plays an important role, it does not directly pump air into the tanks.

The manual air tank drain is used for regularly releasing moisture and contaminants from the air tanks, hence it does not contribute to the function of pumping air. Similarly, the safety valve serves to release excess air pressure to prevent tank overpressure; however, it is not involved in pumping air into the tanks.

In summary, the air compressor is essential for generating and storing the compressed air necessary for the functioning of the air brake system, making it the correct choice in this context.