District Of Columbia cdl Air Brakes - Test 2
Number of questions: 25
Passing score: 80%
Acceptable number of errors: 5
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 Washington D.C. 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.
To DMV Handbooks21. Some air brake systems use alcohol:
To reduce the risk of ice forming in air brake valves.
To make the compressor run more efficiently.
To lubricate parts of the braking system.
To reduce the risk of rust forming on air brake valves.