303.02.0109 Compatible 4-Circuit Protection Valve

What does a 4-circuit protection valve do?

This 4-circuit protection valve serves as a critical pneumatic control component within heavy commercial vehicle air brake systems. It receives pressurized air from the compressor and distributes it to four separate circuits, ensuring that a pressure loss in one circuit does not compromise the entire braking performance. This component is manufactured from high-strength components to withstand demanding operating conditions.

Vehicle and system compatibility

The valve is fitted to DAF, Iveco, and Renault Trucks. It is specifically engineered to work within WABCO systems to maintain optimal pneumatic pressure distribution. By isolating individual circuits, it provides essential safety for the braking architecture of these heavy commercial vehicles.

Installation and technical specifications

Installation should be performed by a workshop technician to ensure correct port alignment and sealing. The valve features an M22x1,5 inlet port and M16x1,5 outlet ports (21, 22, 23, 24). It is vital to verify that the opening pressure of 7,9 BAR and closing pressure of 6,4 BAR align with the vehicle's specific pneumatic requirements during maintenance intervals.

Maintenance and troubleshooting

Regular inspection of the connection points can prevent air leaks that might trigger circuit isolation. If a pressure drop is detected in a specific circuit, this valve helps prevent the total depletion of the air reservoir, maintaining braking capability for the remaining functional circuits.

OE cross-reference

303.02.0109 (4-circuit protection valve) is the equivalent of the DAF, Iveco, Renault Trucks and WABCO OE numbers. This part directly replaces DAF OE number 1518176. It also replaces Iveco OE numbers 04720937, 04749971, 42041486, Renault Trucks OE numbers 5000869119, 5000878469 and WABCO OE number 9347020820.