Answer :
Final answer:
If the service line disconnects while driving, the trailer brakes will automatically engage. This safety feature is designed to prevent the trailer from becoming uncontrollable by automatically activating the brakes in the event of a pneumatic system failure.
Explanation:
If the service line disconnects while you are driving, a) The trailer brakes will engage right away. This is because the service line, also known as the control line or signal line, is responsible for controlling the air pressure used to apply the trailer brakes. In a pneumatic brake system, which is common in heavy-duty vehicles such as tractors and semi-trailers, the service line carries air that is regulated by the brake pedal to apply the brakes. When this line disconnects, the loss of air pressure triggers the emergency brake system of the trailer, causing the trailer brakes to engage automatically to prevent the trailer from becoming uncontrollable.
This safety feature is designed to ensure that if there's a failure in the pneumatic system, such as a disconnection of the service line, the vehicle can still be brought to a safe stop. Therefore, understanding the function and importance of the service line in the braking system is crucial for anyone involved in the operation or maintenance of heavy-duty vehicles.