This pneumatic control device, typically located on the dashboard of commercial vehicles, serves as a critical interface for the operator to manage the vehicle’s braking system. It allows for the application of the trailer brakes independently from the tractor brakes, often used to test the trailer brakes or in emergency situations. Activation usually involves pushing or pulling the valve lever, which then sends pressurized air to the trailer’s brake system.
The presence of this control significantly enhances safety and maneuverability. By providing independent control of the trailer brakes, it allows the driver to correct for trailer sway or prevent jackknifing, especially on slippery surfaces. The history of this component is intertwined with the development of safer and more reliable braking systems for heavy vehicles, reflecting an ongoing effort to improve road safety standards.
