4720726280 Solenoid valve WABCO

WABCO 3/2-way solenoid valve for compressed air brake and auxiliary pneumatic systems on MAN trucks and buses. When the solenoid coil is energised by a 24V DC signal from the control ECU, the valve opens and directs compressed air from the supply port to the output port, actuating the connected pneumatic device — such as a brake cylinder, diff lock actuator, or suspension valve. When de-energised, the valve returns to its normally-closed position and exhausts the output port to atmosphere, releasing the actuated device. Rated for 24V DC operation at up to 8.5 bar. This valve is widely used across the WABCO air brake and suspension system portfolio fitted to MAN TGA, TGX, TGS, and TGM platforms. Common failure modes include internal seal wear causing slow response or failure to hold pressure, coil burnout, and contamination-induced sticking. Before condemning the valve, measure the coil resistance (typically 30–60 Ω for 24V units) and verify that the 24V activation signal from the ECU is present at the connector during commanded operation. Check for water or oil contamination in the air supply — contaminated air accelerates seal wear significantly.