Back in February, we sprang a leak in a coolant line. It was a steel tube going from the motor to the tranny (ISX/Eaton auto shift). We by passed it and came home. Cool weather so the tranny was fine.
After we got home, I went to my friendly dealer and asked them to get me all the coolant lines, both steel and hose. Golly, there's a lot of lines. And they ain't cheap. Some are in tight places too. A few require a second person to help feed in the hose.
I'm cheating and running silicone hose in place of some of the steel, which makes for some creative routing to avoid hot spots. All told, this is about a $1200 project, not counting labor and a new batch of anti-freeze.
So, if your truck came from the rust belt, check those lines and avoid sitting along the road with a puddle under your ride.