Hello, where am I supposed to fill this thing? I changed the stat and only got like a gallon out. since then i only occasionally get heat, and the temp runs high. The problem is that it does not appear to pull it from the over flow tank. please give me the eyes rolling this is how you do it you ***** responses if necessary.

Fill it in into the Overflow Reservoir, that is the only way on these, i know what you are going thru, i had to replace the water pump and it took me a minute to figure out that the overflow container is the way to go