This is for anyone that's considering dexcool, don't. . I had clear water coming out the bottom radiator hose after manually flushing it... Over, and over, and over. I pulled a vacuum on a cooling system and sucked brand new GO5 into it. And this is what I had after I disconnected everything.
This is what I put in.
This what floated to the top. After 10-12 flushes, 2 things of Prestone flush and clean. And 2 cycles of vinegar. This is what I got out.