303.02.0040 KNORR-BREMSE 4-circuit protection valve

The heavy duty protection valve is a critical component within the pneumatic brake system of heavy commercial vehicles. It ensures the proper distribution and regulation of air pressure across multiple circuits to maintain braking reliability. This component is engineered with high-strength components to withstand constant pressure cycles and harsh operating environments.

303.02.0040 is the OE-equivalent of the KNORR-BREMSE AE 4603, II36011, II36011004, II3601105T, and II36011N00 used in KNORR-BREMSE systems. This product is specifically designed to maintain structural integrity under high-pressure demands within the brake circuit.

For workshop technicians performing maintenance or repairs, this valve features specialized port configurations including a primary M22x1,5 port and four secondary M16x1,5 ports. Proper installation requires checking the opening and closing pressure thresholds—such as the 6,3 BAR opening pressure for circuits 21 and 22—to ensure system safety and compliance with heavy commercial vehicle standards.

Regular inspection of the pneumatic connections and monitoring the operating pressure up to a maximum of 20 BAR is recommended to prevent system failures. This part provides a reliable solution for maintaining the pressure stability required for heavy-duty transport applications.