Located in the air intake filter box is a auxiliary thermostat. Made out of plastic, so over time (decades) it becomes brittle and it's two hose fittings tend to crack at the base and brake off. Either scenario is highly undesirable, as it sure will cause leak in the cooling system with following overheating, etc.
I do all my car repair at TechShop, Menlo Park (http://www.techshop.ws/
), conveniently located just a few blocks from my house. They have a nice car port with plenty of heavy duty car tools.