What is the water level at in the radiator??? With the setup you have, I like to make sure the radiator is at the proper level before putting anything in the overflow... You had the intake resealed so it was of course necessary to drain the coolant, now after driving it the cooling system has "burped" itself and hopefully got the air out of the system. With the engine cool, I'd suggest checking the fluid level in the radiator, and getting it to the proper level. Reason being if you overfill the radiator just a bit, the coolant tank will catch the overflow. Without knowing all the details of your cooling system, I'd think a couple inches of coolant in the overflow tank is plenty when everything is cold. The catch tank doesn't hold much, once the engine is at operating temperature if the overflow is empty again, then add a bit more. I prefer to do this and sneak up on the proper level rather then filling everything to the max and dumping a bunch of coolant on the ground......