[Chris Haynes]

I fill my cooling system with the RUST911 mixture. Drove the car for a while. Let it set overnight. Drained it, it came out black. Repeated the process twice more. On the third time the RUST911 mixture came out clear. The block and radiator were both clean as could be. Any and all rust particles were dissolved and gone. Refill with coolant and rust inhibitor and you will have no need for a filter.