Last week the waterpump failed, the truck blew a bunch of fluid and ran hot for less than a minute. New pump and belt installed and fluid changed. Question is did I damage the thermostat. Engine warms normally -- when it hits approx. 190, temp drops down to around 150. I don't notice the temp swings that I used to and the upper radiator hose is rock hard after a decent length of time. After engine cools upper hose softens as pressure is reduced. Short of taking out and testing the Tstat how do I know it's OK?
Thanks in advance for your opinions.

 

Stats are cheap $$$ i would put in a new one i switched to a 180 Degree from NAPA been in over a year no problems , the highs and lows sound to me like it's sticking !

 

I personally believe they are likely to be damaged by engine over heating Ed

 

I'll second what Blizz said, can't hurt to change it. I R+R em every water pump job I do just to be on the safe side. But it does sound like it's hangin up a bit.

 

I'd replace it, cheap insurance. I went with a 180 years ago and really like it.

 

Thanks everyone! Bought the Cummins 190 today and will replace it this weekend. It doesn't make $$$ sense not to. Still miffed at myself for not replacing the waterpump before it failed. Just thought I'd wait a week! Cost me a tow, belt, coolant and now a tstat! (Had the pump in the truck waiting for the weekend!)

 

when your pump went out was it blowing right out of the radator

 

No, it never got that hot. It was pouring out of the water pump. The bearings went out and it drained right at the shaft.

 

Make sure you get all air out of system. Park steep uphill and right side higher make easier.

 

Would not be a bad idea to pull the radiator out and clean it out.

 

The radiator is spotless and i usually remove the tstat and fill the engine there. I then fill the radiator which helps with the air lock issue.

 

I didn't align my truck with a protractor to bleed the air out. Just followed the FSM instructions: fill up through radiator with engine stopped, and it self bleeds. Then, fill the expansion tank and after several heat cycles check fluid levels.
Worked for me.