What should an inspector look for when evaluating the function of the air brakes?

When evaluating the function of the air brakes, it is crucial to assess their ability to engage properly. This ensures that the braking system can respond effectively when needed, providing safety for the driver and others on the road. Proper engagement of the air brakes indicates that the system is functioning as intended, allowing the vehicle to slow down or stop securely.

While aspects like the vehicle's acceleration and brake fluid condition are important in a broader context of vehicle maintenance and operation, they do not specifically address the immediate operational functionality of the air brakes. Additionally, looking for air leaks in the exhaust system is unrelated to the evaluation of the braking system itself. Focusing on the engagement of the brakes directly relates to their performance and reliability, making it the key factor in this assessment.