Hopefully I can make my question clear w/o a picture because I'd rather not have to pull my coolant reservoir. Anyhow, I was flushing and refilling the reservoir because the previous owner used only water in the coolant system and I wanted all traces of that rusty water gone. When I filled the reservoir up to the top (yes I wasn't paying attention to the fill lines) I noticed water coming out of the top. To be clear it was not from where the line goes to the radiator. There was another spot. My question is this: is that okay? Since the overflow tank is obviously not sealed will that cause loss of pressure in the system? As it is, even though my stat is too low for the moment, the system seems to be cycling. Any thoughts from the brain trust?