South Carolina CDL Permit Test - Air Brakes

Number of questions: 25
Passing score: 20
Directions: 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 two, three or four answer choices. To pass, the applicant must answer at least 20 questions correctly. Test questions come from the South Carolina Commercial Driver License Manual. Questions come from the chapter covering: Air Brakes. The Air Brakes endorsement may be used with the Class A, B or C CDL.
You have made error so far
Passing grade —
5 or fewer errors
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1.
Spring brakes come on:
When too much air pressure is lost.
When a control on the dashboard is activated.
When the tires have minimal tread depth.
When the brakes are noisy.
2.
Using an Anti-Lock Braking System (ABS):
Shortens stopping distance.
Shortens brake response time.
Provides less control.
Provides more control.
3.
Vehicles with dual air brake systems:
Maintain full-capacity air pressure in the braking systems even when the vehicle is not running.
Maintain some air pressure in the braking systems when the vehicle is not running.
Must be run to build enough air pressure to brakes to operate properly.
Do not need time to build air pressure before a trip.
4.
If the low air pressure warning signal comes on in a vehicle with air brakes, the driver should:
Test the brakes while driving, but continue driving if nothing seems wrong.
Immediately stop driving.
Drive with the hazard lights activated.
5.
Air tank drains:
Should not be used in cold weather.
Are helpful to remove water and oil from the air tanks.
Are used to move air to the brakes.
6.
What does the air compressor governor do?
Controls when the air compressor pumps air into the air storage tanks.
Controls how quickly air leaves the air storage tanks.
Controls the temperature of the air entering the air storage tanks.
Controls the temperature of the air leaving the air storage tanks.
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