Not sure where to post this. I drive my 65 to Walmart about four miles away. Park and moments later some of the radiator fluid comes out of the overflow tube. Maybe a cup or so. But the heat gauge didn't go over 180. Came out of wallyworld and the radiator seemed full. Drove it home same distance and the same thing did not happen. Is this normal? I'm thinking about putting in an overflow tank.

Steve