Vacuum Vent Valves

The Vacuum Vent Valve controls, (Figure 1) the induction of fresh air into a vacuum system to prevent chemical decay of the vacuum diaphragm that can occur on contact with fuel. The 12A226 (natural cap) is a combined vent and delay valve. Although this valve was intended for use in a specific system with an air cleaner mounting, it may be used in any other vacuum system and mounted elsewhere. The valve should be mounted, as shown, with ports pointing downward for fuel drainback. The vacuum source must be connected to the cap port and the system or device operated, to the body port as shown.