Apparatus for automatically releasing the super-atmospheric pressure of an engine cooling system in response to turning off the engine and preventing the buildup of pressure while the engine is off

An apparatus for automatically releasing the pressure in the cooling system of a liquid cooled engine in direct response to turning the engine off and while the engine remains off, comprising:

• a. a radiator cap, said radiator cap further comprising a shell having a top surface, an over pressure release valve for engaging an outwardly facing seat of a radiator neck of a radiator and a suction return valve, with both said valves connected to said shell;
• and
• b. vacuum controlled means for automatically opening said suction return valve when the engine is turned off in direct response to turning the engine off, said vacuum controlled means further comprising a housing seated on said top surface of said shell of said radiator cap, said housing having an inner perimeter and at least one side wall and a top wall, a push rod vertically aligned for reciprocal movement within a sleeve seated inside said radiator cap, a diaphragm having a perimeter, said perimeter being coextensive with said inner perimeter of said housing and fixed to said at least one side wall of said housing about said diaphragm perimeter, said diaphragm located above said push rod, whereby said push rod reciprocates within said sleeve in response to an up and down movement of said diaphragm, and spring means retained within said housing above said diaphragm and biasing said diaphragm and said push rod downward to contact and open said suction return valve, whereby said suction return valve is opened by said push rod in the absence of engine vacuum and said push rod is lifted above said suction return valve, allowing said suction return valve to close, in the presence of engine vacuum.

An apparatus for automatically releasing the pressure in the cooling system of a liquid cooled engine in response to turning off the engine and preventing super-atmospheric pressure from rebuilding while the engine remains off, comprising:

• a. a radiator cap, said radiator cap further comprising a shell having a top surface, an over pressure release valve for engaging an outwardly facing seat of a radiator neck of a radiator and a suction return valve, with both said valves connected to said shell;
• and
• b. electrically controlled means for automatically opening said suction return valve as the engine is turned off and keeping said suction control valve open while the engine remains off, said electrically controlled means further comprising, a housing seated on said top surface of said shell of said radiator cap, said housing having an inner perimeter and at least one side wall and a top wall, a push rod vertically aligned for reciprocal movement within a sleeve seated inside said radiator cap,
• an electrical solenoid seated within said housing and operatively connected to an engine CPU source of electrical signals responsive to an engine on state and an engine off state, whereby said solenoid is energized when said engine is on, thereby drawing said push rod up and allowing said suction return valve to close and is de-energized when said engine is off;
• and
• c. spring means retained within said housing and biasing said push rod downward, whereby said spring urges said push rod into contact with and opens said suction return valve when said solenoid is de-energized.