Question: My question is about radiator overflow tanks. I’ve always had cars and trucks that had an overflow tank that you would keep full to the cold or hot mark. Checking over my daughter’s ...

Checking Your Coolant Level There are two places under your hood to check coolant level: the overflow tank (which some old cars may not have) and the radiator itself.

Radiator cap Hose going to the coolant overflow tank, a hose that goes from just below the radiator cap to the overflow tank Coolant overflow tank ...

An expansion tank differs from the conventional overflow type in that it operates as a closed system; the cap should not open during normal operation.

Inspect the cooling system for leaks, and then remove the radiator cap and top off the coolant and the overflow tank as necessary.