Quote Originally Posted by Area67 View Post
AF does not go "bad", it can loose the rust inhibitor additive, mostly it get dirty. I pour mine into 5 gallon buckets with a lid, let it sit for 3-4 weeks(dirt and rust goes to the bottom) and then reuse it or give it away to the poor drivers with old junkers in my area.
I would think there may also be a Ph issue as well. I would assume that brand new AF would be neutral.