I have a 2001 gmc sierra c3 with a 6.0 liter.I notice that my overflow tank had a pink fluid in it.I thinking it might be a transmission cooler leak in the radiator?Does anyone else had any problems with this?The truck does not have any coolant in the transmission but it sure looks like transmission fluid in the coolant.I took a sample and letting it settle to get a better idea if it is transmission fluid.Any other suggestion i sure would appreicate it.
Walt

 

The pink coolant is Dexcool engine coolant. It is a GM thing.