My top coolant hose running from the engine back to the rad. becomes almost flat after it makes the bend to go back to the rad. Is this normal? It does not seem to make the truck overheat even in 100 degree FL weather towing 8000 lb.

Try a search, there is plenty of info. on this.

Are you saying it's flat under normal conditions with the engine warm.....or it's going flat when the coolant cools down? If its the second, the cap on the surge tank has a relief that can get gummed up or goes bad. You can get a new cap for real cheap ( around $10 I think ) and that should cure it. If its number one, a misalinged hose might cause it. Have you changed the hose.....and FYI...on the main page at the top is a tab "User CP" if you go to that, on the left you will see "edit signature". You can put the year of your truck, any mods etc which can be helpfull......welcome to the DP

Buy a new overflow cap from Autozone it has diffrent lettering on it than the factory one, do NOT buy a cap from a autoparts store that looks exactly like your factory one, they seem to go bad after a while.

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