The air loss rate for a combination vehicle (tractor-trailer) with the engine off and the brakes on should not be more than:

4 psi in one minute.. Section 5.3: For a combination vehicle, the loss rate should be less than 4 psi in one minute with brakes applied.

The air loss rate for a combination vehicle (tractor-trailer) with the engine off and the brakes on should not be more than:

ANSWER BREAKDOWN
  • A. Incorrect. "2 psi in one minute." is not correct. For a combination vehicle, the loss rate should be less than 4 psi in one minute with brakes applied.
  • B. Incorrect. "3 psi in one minute." is not correct. For a combination vehicle, the loss rate should be less than 4 psi in one minute with brakes applied.
  • C. Correct. For a combination vehicle, the loss rate should be less than 4 psi in one minute with brakes applied.
  • D. Incorrect. "5 psi in one minute." is not correct. For a combination vehicle, the loss rate should be less than 4 psi in one minute with brakes applied.