Packard Forum Index » Post-War (1946-54)

If you can pull the freeze plugs on the side of the block and get inside with a pressure water nozzle, and wire coat hanger.

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The bottom hose is suction so would never have any pressure and there would never be enough pressure for the upper hose to be hard either! Cooling systems do not work like that as it is flow, not pressure, that puts the coolant through the radiator and air flowing through it does the cooling. So much pressure, it would move through the radiator too fast and never get the chance to cool. If you're getting pressure enough to make the upper hose hard, there is a severe blockage somewhere.