I used 20 gallons of distilled water to flush my system(s) a few times. I know that's a bit ****, but that's what I did. I was very relieved that the original coolant was spotless of debris. (drained through a 5 gal. paint strainer) Fantastic how to w/ pic.'s BTW, great job.
I wish they would have given the srt6 a Red (or any other color,lol) drain valve on the bottom of the heat exchanger for the IC. Sure would have been a lot easier.