Recurring Issue

I had the engine rebuilt in Nov. 2009 and started it in May 2010. Engine runs good. New thermostat stuck and rad holding pressure. Replaced the thermostat with 180 degree and all seamed to be OK. Took it today for alignment and 45 minutes of travel both ways. On the return trip temp ran 180 running, at lights idling 200. Thermostat not opening. Should I replace it again or pull it? The rad. cap is 16 pounds. I got no bypass thru the cap. I am concerned that the rad. is going to be compromised. I had it pressure tested but am now seeing light wetness at the upper solder joints.:confused:

You do not want to run with out a thermostat, you state that the stat isn't opening. How do you "KNOW" this? Are you sure that it isn't opening or just guessing that it isn't? Easy and down and dirty way to know what is really going on with the thermostat is to pull it and put it into a pot of boiling water. This will tell if it is opening and a thermomter will tell you at what temp it is opening.

RS

Hose is hard as a rock.

How does the hose hardness mean anything in relation to the thermostat???????

did the engine cool down after you left the light???

Hey guys I am sorry for raising an unnecessary flag. My concern was that when I would return from a short trip i.e. 10 miles I would get out of the truck and notice that the upper hose was bloated and hard as mentioned earlier and I was seeing some weeping from the upper solder joints. "what was I thinkin" of course it is going to build pressure after you turn it off and there is no circulation.
As far as going down the road 45 to 50 mph she ran 180 degrees with a increase to 200 at lights and once going again would gradually return to 180 again. I think all is well! The sky is falling!:o