CDL Air Brakes Endorsement/Topics/Inspection Leak Tests

Inspection Leak Tests practice test: free CDL Air Brakes Endorsement questions

Inspection Leak Tests covers 16 questions in the QuizCram bank (16% of all questions), ranking as the 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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Try 3 sample Inspection Leak Tests questions

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  1. Inspection leak tests1 of 3

    When you pull hard on an s-cam slack adjuster, roughly how much movement at the push rod means it probably needs adjustment?

    The answer

    Answer: C. A slack adjuster that travels more than about an inch where the push rod attaches is likely out of adjustment. Park on level ground, chock the wheels and release the parking brakes before you check it. Three or six inches of travel would mean the brake was badly out of adjustment, and 'any movement at all' is too strict because some slack is normal.

    Source: 5.3.2 - During Step 5 Walk-around Inspection

  2. Inspection leak tests2 of 3

    During the air leakage rate test on a single vehicle, the pressure drop should be less than what?

    The answer

    Answer: C. With a fully charged system, the engine off and the parking brake released, a single vehicle should lose under 2 psi per minute. A combination vehicle gets a slightly looser limit of under 3 psi per minute. Four, six or ten psi per minute would be too much leakage, and a loss that large means you must find and fix the leak before driving.

    Source: 5.3.3 - Step 7 Final Air Brake Check

  3. Inspection leak tests3 of 3

    During the final air brake check, the compressor should start pumping at about what pressure and stop at about what pressure?

    The answer

    Answer: C. Run the engine at fast idle and watch the gauge: cut-in is around 100 psi and cut-out around 125 psi, subject to the manufacturer's specification. If the governor does not behave this way, the system may not keep enough air for safe driving.

    Source: 5.3.3 - Step 7 Final Air Brake Check

Quick answers on Inspection Leak Tests

QuizCram covers 16 practice questions in the Inspection Leak Tests 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.