A tilt valve cartridge for a pneumatic mechanism has a cylindrical housing having two open ends, an annular valve seat secured in one open end, a valve member in tiltable contact with the annular seat and having a valve stem which extends through the valve seat and protrudes from the end of the cylinder, a spring to hold the valve member in a normally closed relationship with the valve seat, a sealing element secured to the cylindrical housing on its exterior surface so as to seal the interface between the cartridge and the mechanism, and retention feature to capture the valve member and valve biasing spring within the cylindrical cartridge. The modular cartridge feature simplifies installation and replacement of the valve in the inlet air passage of the pneumatic mechanism.