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 four answer choices. To pass, the applicant must answer at least 20 questions correctly. Test questions come from the New Hampshire CDL Driver’s Guide. 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. Dollies equipped with ABS are required to have malfunction lamps located where?
Explanation
A dolly equipped with an Anti-Lock Braking System (ABS) is required to have a yellow malfunction lamp located on its left side.
14. What is brake lag?
Explanation
Because air takes time to flow through the air lines to the brakes, air brakes cannot begin working instantly. There is often a brake lag of at least one-half of a second between the moment the brake pedal is pressed and the moment the brakes begin to work. On vehicles with hydraulic brakes, the brakes work instantly when the pedal is pressed.
15. While driving downhill, you should brake until you reach a speed that is ____ below your safe speed, then release the brake pedal.
Explanation
While driving downhill, you should hold down the brake pedal until your vehicle reaches a speed 5 mph below your safe speed, then release the brake pedal. Repeat this process.
16. To make a stop in a vehicle equipped with air brakes, the driver should:
Explanation
To make a normal stop in a vehicle that is equipped with air brakes, you should simply press the brake pedal down.
17. Brakes can get out of adjustment:
Explanation
Brakes are particularly prone to getting out out adjustment if they are hot. Use proper braking techniques to avoid letting your brakes overheat.
18. Most heavy-duty vehicles use:
Explanation
