I opened the hood of my 2004 ML500 today to add some more windshield washer fluid and noticed a green fluid on the belt and pulleys in my engine compartment. I first though it might be my water pump going, but I don't use green anti-freeze. I use the genuine MB clear fluid, and the clear color is what is in my reservoir. I then did some searches on this forum and couldn't really find much else that might explain this fluid color or where it might be coming from. I found one reference to some other Mercedes models using an alternate green ATF fluid, but the fluid I use for my transmission is a bright red color. I in fact had a tranny flush done this summer, and I know the fluid that was replaced was the genuine red stuff. I checked it with the dip stick tool that I have after the flush was done. I checked all the other fluids today, and they were as expected. All of them had the right amount and were the colors they should be. The only fluid I did not check today was the tranny fluid, since I am traveling right now and don't have the dipstick tool with me. I am therefore at a loss to what might be the issue. I have had no issues with car, no indicator lights come on, no problems with the transmission, or anything else for that matter. The car has been working fine. Does anyone have any ideas on what might be going on? I know there are various fluids that get cooled through the radiator, and I am thinking the leak might be with a fitting at the radiator. I would appreciate any help you can give me.