Vacuum Checking Relay
This is a double vacuum check valve connected in the vacuum circuits to maintain vacuum level in system whenever the vacuum drops due to acceleration or momentary wide open throttle operation. The two valves operate independently as follows: 1) Upper plain rubber check valve connected between Black and Purple hoses connected to rotary vacuum valve. Drop in supply vacuum (black hose) will cause valve to close and maintain vacuum in all diaphragms connected to rotary vacuum valves (supplied by purple hose). 2) Lower spring-loaded diaphragm type valve connected in vacuum line between transducer and vacuum motor (White and Yellow Hoses). When engine vacuum drops below vacuum of transducer-vacuum motor system, valve will close and maintain vacuum in motor so that its position will be maintained.