Overheating (not bhg)
 

My car was blowing coolant into the overflow tank but I did not want to post about it because I knew everyone would jump to the conclusion that it was a blown head gasket. I did some detective work and found the problem. I had bought an aftermarket radiator cap with one of those e-z release levers. Well that was shot, so the coolant had no place to go but into the overflow. The coolant is still green, the oil is not milky, and now I can go on my merry way.

Scruffboy

P.S. Do not buy those radiator caps with the orange lever, they suck.

Those 'quick release' caps where invented for use on those old cars that did not use the overflow bottles.

The radiators were like ours, in that they had a top tank. But, those cars were designed with BIG tanks (like my '65 Fury), and you leave an inch or 2 or air on top.

As the pressure builds, the air compresses (water does not), and they only over flowed when there was a problem, or, occasionally, when it was "extremely" hot outside.

You could release the pressure safely with the lever because of the air on top.