When should the trailer hand valve not be used?

The trailer hand valve should not be used to hold a parking unit because it is not designed for that purpose. The hand valve, also known as the trailer brake valve, is primarily intended to assist with braking and controlling the trailer brakes while driving. Using the hand valve to hold a parking unit could lead to unintended movements of the trailer if the air pressure in the system is lost, compromising safety.

In contrast, easing entry into a parking space, assisting braking, and providing better traction on icy roads are acceptable uses of the trailer hand valve. Easing a vehicle into a parking space involves applying the trailer brakes to slow down while maneuvering. Assisting in braking can help maintain control and stop the vehicle safely in various conditions. Although some drivers might consider using the hand valve for traction on icy roads, it should be done with caution and understanding of the vehicle dynamics, as improper use could lead to loss of control. Overall, the trailer hand valve should be used responsibly and within its intended applications for safety and effectiveness.