CDL Practice Question #167

You should never use the parking brake when the brakes are very hot because:

It will not hold
It can damage the brakes or cause warpage
It will release on its own
It will use too much air

Correct. Hot brakes cooled with parking brake applied can warp the drum or rotor, or cause the spring brake to fail to release.

Why this question matters

This question is one of 71 in our Air Brakes bank. The reasoning above comes directly from the AAMVA CDL Manual, the source document used by every U.S. state DMV. Memorizing the underlying rule — not just the letter answer — is what separates passing on the first attempt from a return trip and another fee.

Practice more

Full Air Brakes practice test
Air Brakes study guide
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