Patent ID: 7213619

Claim:
In an automotive cooling system containing a used coolant fluid and having an engine engaged with a radiator for mutual fluid exchange through an upper hose from an upper radiator port to an upper engine port and a lower hose from a lower engine port to a lower radiator port, a method of replacing the used coolant fluid in the system with a new coolant fluid comprising the steps of: a) proceeding with the engine not operating and with the used coolant fluid in a cool state; b) interconnecting the radiator with a sealed first external tank, through a closed shutoff valve, using a first external hose; c) creating a vacuum in the first external tank using a means for creating a suction and then disconnecting the suction creating means from the first external tank, the first external tank being sealed thereby holding the vacuum at steady state therein; d) interconnecting the upper engine port with a vented second external tank containing the new coolant fluid using a second external hose; e) sealing the cooling system so that fluids are constrained to move only within and between the engine, radiator, first external tank, second external tank, upper hose, upper radiator port, upper engine port, lower hose, shutoff valve, lower engine port and lower radiator port, and air is unable to enter the system; f) opening the closed shutoff valve; and g) sucking the used coolant fluid from the automotive cooling system into the first external tank, and thereby simultaneously forcing the new coolant fluid to flow from the second external tank into the automotive cooling system through the second external hose.