When you are driving a combination vehicle, the trailer breaks away and pulls apart both air lines. You would expect the trailer brakes to come on and:

The tractor protection valve to close.. Section 6.2: The tractor protection valve closes to save tractor air.

When you are driving a combination vehicle, the trailer breaks away and pulls apart both air lines. You would expect the trailer brakes to come on and:

ANSWER BREAKDOWN
  • A. Correct. The tractor protection valve closes to save tractor air.
  • B. Incorrect. "The tractor brakes to fail." is not correct. The tractor protection valve closes to save tractor air.
  • C. Incorrect. "The engine to die." is not correct. The tractor protection valve closes to save tractor air.
  • D. Incorrect. "The lights to go out." is not correct. The tractor protection valve closes to save tractor air.