What is the purpose of the glad hands during coupling?

The purpose of the glad hands during coupling is to connect the air lines between the tractor and the trailer. Glad hands are the coupling devices used to link the air brake systems of both vehicles, ensuring that the air brake system operates effectively. This connection is crucial for the safe operation of combination vehicles, as it allows for the equal distribution of air pressure to the trailer's braking system, thus enabling the driver to control the brakes of both the tractor and trailer effectively.

Ensuring that the air lines are properly connected and sealed is essential for the functionality of the entire braking system. If the glad hands are not connected correctly, it could lead to a loss of air pressure, resulting in brake failure and creating a significant safety hazard.