Allow the engine to cool and remove the radiator cap.
Install a radiator pressure cap that has had the spring and the pressure relief valve removed to allow free flow from
the overflow tube.
Attach a rubber hose to the radiator overflow connection.
Put the free end of the hose below the coolant level in a container of water.
NOTE: The pressure cap must be tightly sealed in the top of the radiator fill neck.
Operate the engine at rated rpm until it reaches a temperature of 82ยฐC [180ยฐF].
Check for a continuous flow of air bubbles from the hose in the water container.
NOTE: The engine coolant temperature must be stable to perform this test. An increasing coolant temperature will
give a false indication of air, due to expansion of the coolant in the system.
