What happens when you apply the trailer hand brake while moving the vehicle?

When you apply the trailer hand brake while the vehicle is moving, the service brakes engage. This action is designed to create a controlled braking effect on the trailer while maintaining "service braking" functionality. The service brakes are the primary braking system of the vehicle, functioning to reduce speed and stop the vehicle safely.

Applying the hand brake activates the trailer brake system, which works in conjunction with the service brakes of the truck, providing added braking force specifically for the trailer. This helps to prevent the trailer from pushing against the tow vehicle and maintains stability.

Understanding the functions of both the trailer hand brake and the service brakes is critical for safe operation, especially in emergency situations where a quick yet controlled stopping action is necessary. Knowing that the trailer hand brake engages the service brakes highlights the importance of proper usage and awareness when operating vehicles with trailers attached.