did you use a breaker bar or a small ratchet?

 

I used a wrench and then tried a socket wrench.

 

try a breaker bar as you can get more leverage on the bolt or if you have a pipe and socket could try that combo also.

 

do you think it would work? The head is already starting to get stripped a little. Do you think an 18 inch breaker bar would be just fine?

 

sounds like plenty of leverage. are you using metric or sae socket?

 

15mm socket

 

have you tried an sae socket?

 

Only other think I can think of is applying heat to it.

 

thats what i was thinking earlier also. maybe like a blow dryer or torch on low heat. maybe have some beat on the t stat housing with a hammer and maybe the vibrations will help loosen the bolt.

 

Alright so I got the bolt off. I sprayed a ton of PB blaster. The head was so stripped that I grabbed my 18 inch breaker bar and hammer... I put a 14mm socket on the breaker bar and took my hammer and pounded the 14mm socket onto the 15mm bolt. Gave it a yank and the bolt turned without any problem.

The old thermostat is the same exact thermostat that I just bought new at Napa. I didnt notice anything wrong with the old thermostat, the spring went up and down with no problem. I threw the new thermostat on and started the truck up. Drove it around for 20-30 minutes around the neighborhood and it stayed cool. The needle wouldnt reach half. It would go up as I drove and then as I parked, the needle would go down. Even as I was driving, the needle would go up and then pretty soon it would move down a touch. I also notice that the upper radiator hose gets hot now and it isnt cold. I guess I fixed it?