Vacuum Vent Valve: Description and Operation

Fig. 24 Solenoid vacuum valve assembly. Normally closed type:

Fig. 25 Solenoid vacuum valve assembly. Normally open & normally closed combination type:

Fig. 26 Solenoid vacuum valve assembly. One port normally open & two port normally closed combination type:

There are three types of solenoid vacuum valve assemblies, Figs. 24, 25 and 26. The normally closed solenoid vacuum valve assembly incorporates two vacuum ports and an atmospheric vent. When the solenoid is de-energized, the vacuum valve assembly outlet port is open to the atmospheric vent and closed to the inlet port. When the solenoid is energized, outlet port is open to the inlet port and closed to the atmospheric vent. Some normally closed solenoid vacuum valves also incorporate a control bleed to prevent contamination from the solenoid vacuum valve from entering the intake manifold. This solenoid valve assembly can be used in the exhaust heat control valve , throttle kicker, air dump or air diverter valve systems.
The normally open and normally closed solenoid vacuum valve assembly, incorporates two solenoid valves which operate independently of each other, but are mounted to a single mounting bracket. Each solenoid valve controls a different device. This valve assembly is used to control the Thermactor air bypass and Thermactor diverter.
The one port normally open and two port normally closed solenoid vacuum valve assembly also consist of two solenoid valve assemblies mounted to a single mounting bracket. This valve assembly is used to control the A/C throttle kicker and choke pulldown.