Free CDL Quiz

Why should you drain air tanks regularly?

a.To prevent the compressor from overheating
b.To remove water and oil that collect and can damage the brakes
c.To reduce air pressure to safe levels
d.To test the low air pressure warning

Explanation

Compressed air contains water and compressor oil. These accumulate in air tanks and can damage the braking system, cause corrosion, and reduce braking effectiveness, especially in cold weather when water can freeze.

← Back to Class B CDL Air Brakes Test #1

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About the CDL Exam

The CDL (Commercial Driver License) exam tests your knowledge of commercial driving rules, safety procedures, and vehicle operation. You must score 80% or higher to pass the written knowledge test. The exam covers general knowledge, air brakes, combination vehicles, and various endorsements.

This question is from the Class B CDL Air Brakes Test #1 section. Practice with more questions from this category to build confidence before taking the official DMV test.

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