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 the air in the tractor, while the trailer

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. Incorrect. "The tractor brakes to lock." is not correct. The tractor protection valve closes to save the air in the tractor, while the trailer emergency brakes activate.
  • B. Correct. The tractor protection valve closes to save the air in the tractor, while the trailer emergency brakes activate.
  • C. Incorrect. "The trailer lights to flash." is not correct. The tractor protection valve closes to save the air in the tractor, while the trailer emergency brakes activate.
  • D. Incorrect. "The engine to stop." is not correct. The tractor protection valve closes to save the air in the tractor, while the trailer emergency brakes activate.