Finally, the end to the mysterious, over heating only while towing in terrible hot weather and never any other time, issue. Take a look.


It was opening just enough to keep the truck cool under 95% of the year even when towing. Now I know, knew I should have replaced it sooner.



A little bit of rust clean up.



New tank so the fluid level can actually be checked.

 

Looks like someone had installed the wrong (short) thermostat before you got into it.

 

That is my thinking, too, Pete.

Pop

 

That could be, I wasn't thinking about that. When I first bought the truck it cooled just fine even when pulling large trailers, without a problem. After about 8 months or around the time I quite hauling campers commercially it started to stick.