I use a two part radiator flush, I think it's Dupont, comes in a can and is a powder. Follow the instructions on the can. I get a little sloppy with how long to leave it in the system. The one thing I definitely do is flush it real good till the water is clear. I've had good luck with it no real problems. In addition to the antifreeze I also add a can (bottle?) of rust inhibitor and water pump lube. Hope that helps.

Larry

I don't own a vehicle that isn't old enough to drink.