Well I drained and filled my 2012 suburban today. Still not impressed with dex cool ! Took the overflow tank out to rinse it out and boy what a mess.
Dex crap coating the inside of the tank and the hoses coming from it.
Even though my suburban only had 45000 miles on it I'm convinced time and air are the killers of dex. The fluid itself that drained out seemed nice and reddish orange bit quite the layer of Scum on stuff.
I suspect air is somehow introduced into the overflow tank through this hole on the bottom.
Not sure how long I will leave this batch of dex in but next time I do it I need to order a new overflow tank and flush the system.
Weird thing is I threw my bottle of prestone flush in the overflow tank with hot water and let it sit and shook for 20 min and it did not even cut into the crud.
After discovering the mess I took the upper radiator hose off on the other side of the radiator to see if scum was in there and it appeared to not be as prevalent so hoping it is confined to areas near the overflow tank.
