CDL Air Brakes Endorsement/Topics/System Parts
System Parts covers 14 questions in the QuizCram bank (14% of all questions), ranking as the second 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.
14 questions, the second biggest topic. The ring is its size next to the biggest.
System parts1 of 3
The answer
Answer: B. Air brakes are described as three systems working together: service brakes slow the moving vehicle, parking brakes hold it stopped, and emergency brakes use parts of both to stop it after a failure. Treating them as one system hides the separate controls and air paths you must inspect.
Source: 5.1 - The Parts of an Air Brake System
System parts2 of 3
The answer
Answer: D. The service brake is the everyday circuit: pedal pressure sends air to the chambers and releasing the pedal lets it out. Parking and emergency braking are separate functions even though they share components. The yellow knob is the parking control, and spring brakes or the trailer protection valve belong to emergency and parking braking, not to normal stops.
Source: 5.1 - The Parts of an Air Brake System
System parts3 of 3
The answer
Answer: A. Air pressure pushes the rod out, the rod moves the slack adjuster, and the adjuster twists the camshaft. That rotation turns the s-shaped cam so the shoes press against the inside of the drum. The drum, the supply valve and the governor are not moved by the rod: the drum turns with the wheel, and the valve and governor sit elsewhere in the system.
Source: 5.1.8 - Foundation Brakes
QuizCram covers 14 practice questions in the System Parts 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.