Single-Function for Standard Cooling

When coolant temperature is below 155°F (68°C) on 6-cylinder and V8 engines, or 120°F (49°C) on 4-cylinder engines, check ball is held against inner seat by spring tension. Manifold vacuum enters through port "1" and is applied through port "D". See Figure .

When temperature goes above specified limits, check ball is moved up in valve and manifold vacuum is applied from port "2" to port "D", by-passing delay valve, on 4-cylinder engines, or carburetor ported vacuum is applied from port "2" to port "D" on 6-cylinder and V8 engines.