Humm.. it is not directly on the bottom of the radiator, it is on the bottom driverside corner, but not directly on the bottom. About an inch or two above the bottom is a drain petcock. Using pliers, pull out as you turn counterclockwise (1/4 turn is all that is required). There is a little drain hole on the very bottom of the radiator along the drivers side, look up from there, inside side of the radiator, not outside. I'm not sure what else to say, anyone else?