Answer :
Final answer:
Before you back under a trailer, make sure that the tractor protection valve is normal. (Option B)
Explanation:
Before backing under a trailer, it's essential to verify that the tractor protection valve is in the normal position. This valve plays a critical role in preventing the trailer brakes from engaging while the tractor is in reverse. When the tractor protection valve is in the normal position, it allows the air to flow freely between the tractor and the trailer, ensuring that the trailer brakes remain disengaged during the backing maneuver. This is crucial for safe operation, as engaging the trailer brakes while backing can cause the trailer to stop abruptly, potentially leading to accidents or damage.
To check the tractor protection valve, start by ensuring that the air supply knob is in. This ensures that the air is flowing properly to the valve. Next, visually inspect the valve to ensure that it is in the normal position. The normal position is typically indicated by a notch or mark on the valve. If the valve is not in the normal position, do not attempt to back under the trailer. Instead, consult the vehicle's manual or a qualified mechanic for assistance.
In conclusion, ensuring that the tractor protection valve is normal before backing under a trailer is crucial for safe operation. By following these steps and verifying the position of the valve, you can help prevent accidents and ensure that the trailer brakes remain disengaged during the backing maneuver, promoting safety for yourself and others on the road. (Option B)
