Air Brakes
This endorsement is required for driving a vehicle with air brakes. To receive this endorsement, applicants must pass a written test. The test consists of 25 multiple choice questions. Each question has three or four answer choices. To pass, the applicant must answer at least 20 questions correctly. Test questions come from the Wyoming Driver License Manual for Commercial and Heavy Vehicles. Questions come from the chapter covering: Air Brakes. The Air Brakes endorsement may be used with the Class A, B or C CDL.
Number of Question
Passing Score
13. An air compressor governor will stop the compressor from pumping air once the air tanks have an air pressure level of:
Explanation
An air compressor governor will stop the compressor from pumping air once the air tanks are at an air pressure level of 125 psi. This air pressure level is referred to as the "cut-out" level.
14. What is removed when an air tank is drained?
Explanation
In an air brake system, air tanks have drains to remove accumulations of water and compressor oil. Allowing water and oil to accumulate in the system could cause damage to the brakes.
15. The service brake system:
Explanation
Air brakes consists of three separate braking systems: the service brake system, the parking brake system, and the emergency brake system. The service brake system applies and releases the brakes when you use the brake pedal while driving normally.
16. If the low pressure warning light comes on while you are driving:
Explanation
When driving a vehicle with air brakes, if the low air pressure warning light comes on, it is important for you to stop and safely park your vehicle as soon as possible. There may be a leak in the system. Controlled braking will remain possible only as long as there is enough air left in the tanks.
17. What do air brakes use to make the brakes work?
Explanation
Many large CMVs are equipped with air brakes. An air braking system uses compressed air to operate.
18. A low air pressure warning signal should activate:
Explanation
