A disposable air/water valve may include a main stem providing an air passage through the center bore of the main stem. A method for manufacturing a disposable air/water valve may include several steps. The main stem is molded, and placed in a mold for over-molding seals onto the main stem. Prior to the next steps, the retaining ring, button cap, and boot may be molded. The back end of the main step is placed through the center of the retaining ring and resilient member (e.g., spring). The button cap is then placed on and secured to the main stem.