We just had a posting on a Subaru radiator treatment chemical that turns out to be a "stop leak" type product. However, I was thinking of what a person could do to make sure the chemicals are up to date in a coolant. I usually go 5 years between changes with long life coolant. I suppose if I was worried I could also Turkey Bast the coolant tank, removing say, a quart to 1/2 gallon of coolant and replace it with fresh mixed coolant. That would ensure around 5 to 10% of fresh coolant in the cooling system once a year or so. I also came across a "replenish" additive with or without a "stop leak" from Prestone. Does anyone use either one of these strategies?
SF
SF