SuperBusa,I was looking around tonight and did notice some pinkish powder residue around the base of the hose that runs between the catch tank and the radiator pressure cap neck. It looks like it has seeped a small amount of coolant in the past. I'm wondering if maybe that's where I've lost some, and if it was also the source of the coolant smell at times. Like some others here, I have smelled coolant near the front, right of the truck, but it doesn't do it all the time. Maybe this hose was seeping on/off at times over the last 1.5 years. I'm going to watch it for signs of new leakage if I ever smell vapors again. Maybe the dried crud has sealed it up again. This hose in not under pressure, so it seems it would be hard for it to leak unless there's some kind of flaw on the tank nipple where the hose attaches. Might pull it off and inspect if it shows more signs of leakage.
Anyone else who's seen the coolant level drop in the catch tank should check this hose for signs of leakage (pink powder residue).
I have noticed the exact same issue on my truck. The hose leading from the radiator to the catch tank is leaking a small amount of coolant. It also had some dried coolant crust on it. I recently topped the coolant off, and noticed it was dropping slowly again. I think it must be the hose leading into the catch tank causing this issue.
Did you ever get it resolved or let the dealer look at it? I would like to have this fixed if possible. It should not be leaking.