303.01.0009 Relay Valve Compatible with Mercedes-Benz

What does a relay valve do?

This relay valve plays a critical role in the pneumatic braking system by facilitating rapid air pressure transfer triggered by a pilot signal. By directing pressurized air from the main reservoir directly to the brake chambers, it minimizes response lag in long air lines, ensuring fast and reliable braking action for heavy commercial vehicles.

Compatible vehicles and engines

This component is engineered to be compatible with Mercedes-Benz and Volkswagen Truck vehicles. It is also fitted to other heavy commercial vehicle applications requiring precise pneumatic control. The unit features specific port dimensions including M22x1,5 VOSS for ports 1 and 2, and M16x1,5 VOSS for port 4, supporting a maximum pressure of 10 BAR.

Installation and maintenance

For proper installation, technicians should ensure all connections are seated correctly on the chassis between the main reservoir and the brake chambers. Regular inspection of the VOSS ports and seals is recommended to prevent air leaks and maintain consistent braking response times during heavy-duty operation.

Selection guidance

Consult your authorized distributor to confirm specific fitment requirements for your vehicle's braking configuration.

OE cross-reference

303.01.0009 (Relay Valve Relay Valves) is the equivalent of the Mercedes-Benz, Volkswagen Truck and WABCO OE numbers. This part directly replaces Mercedes-Benz OE number 3864297044. It also replaces Volkswagen Truck OE number 2V2607359A and WABCO OE number 9730110070.