303.02.0059 KNORR-BREMSE Compatible Multi-circuit Protection Valve

The multi-circuit protection valve plays a critical role in the pneumatic brake system of heavy commercial vehicles, ensuring that air pressure is distributed safely across different circuits. This component is designed to isolate pressure drops in one circuit from affecting others, maintaining high-strength performance during operation. Its robust construction provides reliable protection for critical braking functions.

303.02.0059 is the OE-equivalent of the KNORR-BREMSE AE 4503 multi-circuit protection valve used in heavy commercial vehicle brake systems. This part is specifically engineered to meet the stringent requirements of professional workshop technicians and fleet managers who demand precision in pneumatic regulation.

The installation process requires careful attention to the specified port dimensions to ensure a leak-free connection. The valve features four M16x1,5 ports (Ports 21, 22, 23, and 24) and one M22x1,5 port (Port 26). Regular maintenance checks of the opening and closing pressures—8 BAR for opening and 7,5 BAR for closing—are essential to ensure the system operates within safe parameters during service intervals.

For workshop technicians, this part offers seamless integration into existing KNORR-BREMSE systems. Monitoring the interplay between the different pneumatic circuits through this valve helps prevent total system failure in the event of a localized leak or component malfunction.