I have tried reading other posts to see if this has already been answered, but it's impossible to read every post... so apologies up front if this is a repeat:
My 2004 6.0L F250 is leaking coolant while not running and just sitting in the driveway. After more than a week of not driving my truck I came home and saw a wet spot in the driveway near the front of the engine, just off center to the passenger side. It is seems to be a slow leak and I can't isolate where it is originating. Since finding the leak I haven't driven or started the truck (a little more than a month ago). The leak has finally stopped as there can't be any coolant remaining. The degass bottle is empty. There doesn't seem to be any foam/water on the dipstick. Before I take the truck to the mechanic I was hoping someone could provide a few pointers or suggestions.
I am the original owner and the truck has approx. 75k miles.
Appreciate any help/advice.

 

My best guess would be the oil cooler to EGR cooler hose--it's either orange or blue (probably orange) and about 3" long. The orange one has been upgraded with the blue one and is a common problem. It's a little hard to see: Page 13: Component Locations In the pic's it's under the turbo outlet (blue cap)

In this pic: http://dan.prxy.org/Truck/6L_bible_h.../Page_017.html it would go where the small red "S" shaped line is between the engine and the EGR cooler

 

I posted to another one of these... Also Check your heater bypass valve near the oil fill cap (it has a small vacuum line going into it) and do you have a coolant filter added?

 

I would agree it could be the oil cooler to EGR cooler hose. I had an issue late last year that sounded similar to yours. It ended up being a bad clamp on the metal heater hose tube by the alternator. It was a very slow leak that had me puzzled. I finally just started replacing clamps until the leak stopped. There were no obvious hose breakages or defects showing.

 

They can be tough i used mirrors lights camera's snake camera

finaly a wet finger found my leak location lol

the tops of these motors let fluids go strange places ..mines going in Monday for a diesel leak on top I can not find

 

If it ends up being the EGR cooler hose, might want to read this thread before starting.

https://www.ford-trucks.com/forums/1...e-install.html

Here is the parts numbers for it.

https://www.ford-trucks.com/forums/1...ml#post9575357

 

After doing my coolant flush I had a small leak in the lower
radiator hose @ the radiator. It seems I put a small hole into
it loosening and tightening the clamp so many times
removing it and putting it back on.

I temporarily put an additional clamp on it and that has
stopped the leak. When I replace the oil & egr coolers
in the next 3 weeks or so I'll also replace the lower hose
at that time and flush again.

 

You got a Royal Flush!