53 Ford Jubilee Thermostat?

I had to replace the head gasket in my jubilee. While doing that I drained the block using the drain hole on the side of the engine. Part of the gasket set was the new thermostat gasket, so I removed the old
one, cleaned up the housing and then replaced. After getting everything back together the old girl is running better than ever. The only problem is it doesn"t appear the thermostat is opening. I figure
either there"s no liquid behind it or the thermostat went out on me. Any tips on how to refill the block when you drain it completely? I don"t have another gasket and I really didn"t want to have to order a
new thermostat and wait for it to arrive. I"ve got fields that need to get worked this weekend before it rains even more. Here"s the process I followed to refill the coolant:

- Opened drain hole on block
- filled radiator until drain hole had liquid coming out steady
- closed drain hole, continued filling
- Once full, started engine and topped off radiator until it seemed steady
- closed radiator cap

After a few minutes of running around 1200 RPM, it went above 200 degrees. I shut it off when it approached 240, but never saw the temp drop (indicating the thermostat had opened).

First question would be if you installed the thermostat in the correct direction with the copper heat-sensing bulb down.towards the cylinder head.

Other possibility would be trapped air, lots of guys advocate drilling small hole in the thermostat to let air pass through.

I've done it, but try to avoid doing that because I live where it gets REALLY cold and even a small hole will bypass enough coolant to slow warmup in bitter temperatures.

I just replaced the thermostat on my NAA about 3 weeks ago. The original one should have had the word "top" stamped on it and that should up when you put it back in. The new one I got had that little hole that Wore Out referred to drilled in it. The thermostat should start to open at 160 degrees and be fully open at around 180. If your tractor gets much past 180, shut it down or you will be replacing the head gasket again or worse.

Did you test the thermostat before putting it back in? Did the head gasket fail from overheating? Do you know your temp gauge is accurate? It's awfully hard to get air trapped in these cooling systems. I would bet either a failed thermostat or it's installed backwards. It's a quick job to pull the thermostat and check it, that might be the quickest way to eliminate it as a suspect.

Thanks for the ideas everyone! I just kept running until it was warm, let it cool down and then topped off the radiator. After a few cycles it started working properly! So glad I didn't have to replace the thermostat. I love this tractor!