Which of the following is not a component of the air brake system?

The brake lights are not a component of the air brake system. The primary function of the air brake system is to provide stopping power for the vehicle using compressed air, which is generated by the air compressor. The brake pedal is a critical component that the driver uses to activate the braking system. Spring brakes serve as a safety feature and are part of the air brake system, providing additional braking force and holding the vehicle in place.

In contrast, brake lights serve a different purpose. They are an essential safety feature that alerts other drivers when the vehicle is slowing down or stopping, but they do not directly contribute to the braking process itself. Thus, while brake lights are important for signaling, they do not function as part of the air brake system.