The Trailer Hand Valve (Trolley Valve) should be used:

Only to test the trailer brakes.. Section 6.2: The trailer hand valve should be used only to test the trailer brakes. Do not use it while

The Trailer Hand Valve (Trolley Valve) should be used:

ANSWER BREAKDOWN
  • A. Incorrect. "To stop the rig in normal driving." is not correct. The trailer hand valve should be used only to test the trailer brakes. Do not use it while driving.
  • B. Incorrect. "To park." is not correct. The trailer hand valve should be used only to test the trailer brakes. Do not use it while driving.
  • C. Correct. The trailer hand valve should be used only to test the trailer brakes. Do not use it while driving.
  • D. Incorrect. "To correct a skid." is not correct. The trailer hand valve should be used only to test the trailer brakes. Do not use it while driving.