Well, I didn't get any input, so I forged ahead with a repair. The leak was a single drip about every 30 seconds while the system was under full pressure, so pretty minimal for now.

I took off the upper hose and my radiator already has the aluminum support in the neck. The hose has not been off since the car was new, and it has 105K miles. So, it was never over-tightened. It has just fatigued from the heat cycles and miles.

I could not actually see a crack, but I guessed that it was coming from the sharp joint between the neck and the tank. I used some of the loctite brand radiator/fuel tank repair epoxy and added a patch to that area. I sanded it first and cleaned it well with brake cleaner. The patch was the 2-part putty type epoxy.

It's all good for now, and I'll report back whether the leak returns.

__________________
D.H.

04 ML500
02 E430

Experience is something you don't get until just after you need it.