CDL Air Brakes Endorsement/Topics/Dual Brakes Spring

Dual Brakes Spring practice test: free CDL Air Brakes Endorsement questions

Dual Brakes Spring covers 12 questions in the QuizCram bank (12% of all questions), ranking as the fifth biggest domain for the CDL air brakes endorsement exam. Questions are written against the official Original practice questions on the air brakes endorsement, written from the federal knowledge requirements in 49 CFR Part 383 and the public CDL manual facts. The real test is a multiple-choice knowledge test, and you need 80% to pass. Try the 3 free sample questions below to test your understanding of these core rules.

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12 questions, the fifth biggest topic. The ring is its size next to the biggest.

Try 3 sample Dual Brakes Spring questions

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  1. Dual brakes spring1 of 3

    A dual air brake system uses two separate air systems that share what?

    The answer

    Answer: C. The two circuits have their own tanks, hoses and lines, but the driver works them through one set of brake controls. That separation is what lets one circuit keep braking when the other loses pressure. The tanks, hoses and lines are not shared, which is why choosing 'one common set of tanks' or a shared drain would defeat the purpose of having two circuits.

    Source: 5.2 - Dual Air Brake

  2. Dual brakes spring2 of 3

    What holds the spring brakes off while a vehicle is driving normally?

    The answer

    Answer: B. Powerful springs are held compressed by air pressure whenever the system is charged. Release or lose that air and the springs extend to apply the brakes, which is why spring brakes serve as the parking and emergency brake. There is no mechanical latch, hydraulic fluid or vacuum reserve in the system: it is the air itself that keeps the springs compressed.

    Source: 5.1.14 - Spring Brakes

  3. Dual brakes spring3 of 3

    Before driving a vehicle with a dual air system, how much pressure should both circuits build?

    The answer

    Answer: C. Allow the compressor time to bring both the primary and secondary circuits to a minimum of 100 psi. Watch both gauges or needles and confirm the low pressure warning has shut off before you move. Fifty-five psi is only the warning level, and 80 or 150 psi do not match the minimum the manual gives for starting out.

    Source: 5.2 - Dual Air Brake

Quick answers on Dual Brakes Spring

QuizCram covers 12 practice questions in the Dual Brakes Spring domain, mapped directly to the official examination blueprint.

The benchmark score is 80% (Multiple-choice knowledge test · 80% to pass (49 CFR 383.135) · item count set by your state).

Yes. All questions on QuizCram are written against official handbooks and blueprint specifications with legal citations.