For a single vehicle with engine off and brakes applied, the maximum allowable air-loss rate is:
Correct. A single vehicle is allowed no more than 3 psi/min with brakes fully applied.
CDL Practice Question #117
Category: Air Brakes
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.