303.02.0034.02 4-Circuit Protection Valve Kit for Volvo and Mack

What does a 4-circuit protection valve do?

A 4-circuit protection valve repair kit restores the vital seals and internal components of the protection valve, which is responsible for distributing air pressure into independent circuits. By utilizing high-strength components, this kit helps prevent air leaks from compromising the entire pneumatic system. This ensures that a leak in one circuit does not drain the pressure required for the front axle, rear axle, or parking brakes.

Compatible vehicles and engines

This repair kit is compatible with WABCO systems used across various heavy commercial vehicles. It fits several Volvo models including the FH16 (D16C, D16E, D16G), FM series (FM11, FM12, FM13, FM10), and VNL series. It is also suitable for Mack Pinnacle and Granite models, as well as Renault Trucks Magnum, Kerax, and Premium series. These kits are also fitted to DAF trucks.

Installation and maintenance guidance

For professional technicians performing maintenance, it is essential to verify the valve housing markings before installation. Using the correct kit ensures that the spring calibration and diaphragm sealing meet factory specifications. Proper installation helps maintain the correct circuit priority and pressure balance within the vehicle's braking system.

System maintenance and troubleshooting

Regular inspection of the pneumatic system can prevent sudden pressure drops. Replacing worn seals during scheduled maintenance helps extend the service life of the protection valve assembly without requiring a complete unit replacement.