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Illinois 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. To pass, the applicant must answer at least 20 questions correctly. Test questions come from the Illinois Commercial Driver’s License Study Guide. Questions come from chapters 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.
What must be on an air tank in an air-braked vehicle?
A check valve
A lock
A trap door
An oxidizer
3.
Air tank drains:
Allow rain water to enter the tank.
Are used to drain water and compressor oil from the air tank.
Should never be opened.
Must remain open during transit.
4.
The air compressor governor controls:
When the air compressor pumps air into the air storage tanks.
How fast air is pumped into the air storage tanks.
The temperature of air pumped into the air storage tanks.
The speed of the vehicle.
5.
Brake fading is caused when:
Brakes are not used often enough.
Brakes overheat.
Brakes are too cold.
Brakes are wet.
6.
What does ABS do?
Prevent wheel lockup
Prevent the air compressor from overheating
Prevent the front brakes from being used on ice
Prevent the brakes from being used if downshifting would be more effective
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