Why should you avoid using the trailer brakes while stopped on a hill?

Avoiding the use of trailer brakes while stopped on a hill is important because it can cause a sudden shift and may lead to a loss of control. When the trailer brakes are applied on a grade, there is potential for a significant weight transfer, which can affect the stability of the vehicle. If the brakes are released suddenly or if there is an unexpected movement, the trailer could push the towing vehicle forward or backward sharply. This abrupt change can lead to difficulties in controlling the vehicle, especially in situations where the towing vehicle is on an incline and may even cause a jackknife scenario or loss of traction.

Proper management of brake systems while on an incline helps to ensure that both the truck and the trailer remain stable, allowing for smoother operation when it’s time to accelerate or begin moving again. Using the parking brake or service brakes of the towing vehicle is a safer approach to prevent the potential instability associated with applying trailer brakes in such circumstances.