Reviving an old thread here...
Was changing my oil earlier this week and noticed I had a coolant leak. It wasn't bad, but definitely leaking. I never noticed because the coolant was collecting on the skid plate and not dripping onto the pavement until I moved the truck. I couldn't find the source of the leak. Hoses seemed fine and there was no visible damage to the radiator. I added 1/2 gallon of coolant and took it to the dealer to have it pressure tested.
They tested it and found the leak coming from one of the seams on the bottom plastic reservoir. No idea how this happened since that part is fairly well protected from getting hit. Dealer said it was probably a weak point and was just a matter of time. They ordered a new radiator and are installing it as I type this. All covered under original factory warranty - 30k miles only.
Just thought I'd share for anyone else searching.
