Replace a Head gasket on a 2000 Mountaineer

Okay - here's an update to my problem with my daughter's mountaineer. Yesterday my nephew and I went to her college. We had his pressure test kit for the coolant system and some of his other tools - he's a mechanic. What we found was a freeze plug on the head next to the firewall leaking coolant. He said that the factory installs these types of plugs made of steel and some softer metal such that if the vehicle overheats the plug will melt and protect the head. Not sure how that works because it seems like you would want to keep the fluid in. He said it was a tattle tail incase other systems fail to indicate an issue such as the temp gauge goes out and you have a water pump problem or some other problem that is not immediately visiable. Does this sound correct? The problem is we could not find a replacement plug even the local ford dealership didn't have one and we couldn't stay up there. So I took it to a shop still not knowing what caused the overheating or to what extent the damage was.

It could be the heater core also. Or just one of the lines split. The bypass valve would prevent flow through these tubes when the heater is turned off--

Welcome to this forum! A cooling system pressure tester would eliminate any guess work.

THANKS for the reply. It is on the drivers side away from the heater lines where they come throuhg the firewall. It appears from her description to be spraying towards the firewall. She didn't have a mirror to see where it was coming from exactly and with the steam and heat, I didn't want to get her burned.

THANKS for the reply. can I get one myself? What about removing the radiator cap and seeing if the pressure makes any diff?

Some places like Autozone have a pressure tester as part of their tool loan program. Here's my product review: http://www.explorerforum.com/reviewpost/showproduct.php/product/231/cat/500

THANKS! I will go to the autozone nearby!