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Air Brakes Practice Question 10

Restriction L if not passedAir Brakes · Question 10

The proper braking technique for a long downgrade is:

• AContinuous light service brake pressure
• BSnub braking — apply firmly to slow 5 mph below safe speed, then release
• CRiding the brakes lightly
• DHard intermittent stabbing

Correct answer: B. Snub braking — apply firmly to slow 5 mph below safe speed, then release

Why: Snub braking applies firm pressure to bring the vehicle 5 mph below your target speed, then releases until you climb back to the target. This lets brakes cool between applications.

How this question fits the Air Brakes test

An air brake failure on a loaded combination vehicle can cause runaway, jackknife, or fire. The CDL Air Brakes test exists because air systems behave very differently from hydraulic brakes — drivers must understand pressure build, air loss tolerance, and stopping distance under load.

Study technique for this topic

Memorize the seven steps of the air brake pre-trip check, the leak-down rates for single and combination vehicles, the warning signal pressure threshold, and the spring brake automatic application pressure range. Practice the order of operations — never rely on muscle memory in the booth.

Related Air Brakes practice questions

• Q14. A dual air brake system has:
• Q27. Stab braking is appropriate on:
• Q40. The ratio of brake force from the front service brakes versus rear is balanced by:
• Q53. The S-cam in a drum brake system rotates to:
• Q4. The air pressure warning signal must activate before pressure drops below:

Continue your CDL preparation

The Air Brakes portion of the CDL knowledge exam covers more than this single question. Use this site's full Air Brakes bank to drill every topic, then test yourself with one of our state-specific practice sets to confirm you are ready for the actual DMV exam in your state. Always check your state's CDL handbook for any local addenda before the test day.

If you are still building your overall CDL foundation, start with the General Knowledge bank — every CDL applicant must pass it — and then work outward to the endorsements you plan to add.