Leathermang,

The mess of which I wrote would be due to opening the thermostat housing and releasing the antifreeze. There is no drain plug on the bottom of the radiator, so it is either a mess generated by removal of the thermostat housing or the lower radiator hose. My car does have the compressible rubber sealer and I did not use any other liquid sealer on the assembly.

I did not test the thermostat in hot water before I installed it. I have never purchased a bad thermostat and it didn't occur to me to test it before putting it in the car. My bad, I guess. There is not a small hole in the flat part, and I do not have the seperate burp pipe.

I replaced the thermostat because I changed the coolant, replaced the water pump, fan clutch, belts and hoses and consequently had easy access to everything. There were no overheating symptoms or any other issues, just my miserable attempt at good maintenance.

Tom