Radiator water levels

[Ronald G. Stephenson]

All old cars need room at the top of the radiator tank for expansion. With pressure caps of 4 to 7 pounds, they only amount to a pressure release valve. To be sure, it is important to have water/anti freeze in your overflow bottle, with the hose below the water level. Ok, engine heats up, water expands, and that space in the top of the radiator gets filled up. If it gets hotter, the water has to go somewhere, and it is important to fit an overflow bottle. Upon cooling down, the water will be drawn back into the radiator. Years ago, I was shown by an experienced mechanic to just cover the 'fins' in the radiator, and never 'fill it up'. Very easy to construct an overflow tank or bottle if you do not have one, and it can be easily hidden from view. Do NOT fit a higher pressure cap unless you want more leaks than you can imagine from every fitting on the engine.