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 answer choices. To pass, the applicant must answer at least 20 questions correctly. Test questions come from the Idaho Commercial Driver’s License Manual l. 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. Air tank drains should:
Explanation
In an air brake system, air tank drains are used to remove water and compressor oil from the air tanks. When operating a drain, be sure to drain the tank completely.
14. When operating a vehicle with a dual air brake system, the driver should:
Explanation
Before driving a vehicle with a dual air brake system, allow time for the air compressor to build up a minimum of 100 psi pressure in both the primary and secondary systems. Watch the air pressure gauges to monitor the pressure levels.
15. If an air compressor is belt-driven, the belt should be routinely checked to ensure that it is:
Explanation
If your vehicle has air brakes, the air compressor drive belt should be checked before each drive. Check the tightness of the belt and verify that it is in good condition.
16. Air storage tanks:
Explanation
In an air brake system, the air storage tanks hold compressed air to be used by the brakes. The number and size of air tanks varies among vehicles.
17. Brake linings should be:
Explanation
Brake linings should not be loose or soaked with oil or grease. They shouldn't be dangerously thin.
18. How much distance will an air brake-equipped vehicle need to come to a complete stop if it is traveling at 55 mph under ideal driving conditions?
Explanation
