[JK McDonald]

Hey Honerboy - One other point concerning the Factory Style Heater Control Valve is that some seem to seal off better when water is flowing in One Direction better than the other. Before installing the new valve - select closed and then blow air through the valve from both ends. I've been told that the flap inside is at an angle so when the water pump pressure is felt on the correct side of the flap it pushes it farther toward the sealed direction.

Also you might consider installing an additional Generic Manual Shut Off Valve in series with the factory Heater Control Valve. I control the ADDED Manual Heater Valve with a short "T Handle" cable that sticks up by the Radiator Reservoir Tank.

The reason for adding the Manual Valve is because in the heat of the summer - the factory Heater Control Valve often creeps open when you turn off the motor and your HVAC vacuum lines slowly leak off. Since the Factory Heater Control Valve now falls to the open condition - your AC must first cool off the hot water in the internally exposed heater core each time you fire up your car before you begin to feel any cold air. In Texas this can be a problem.

Each fall I simply select the added Manual Heater Control Valve to "OPEN" which allows the factory heater water circuitry to operate normally.

Good Luck, Michael