Thread: Phosphoric Acid in radiator?

Tweet

I have been playing with this stuff but while researching it I see you could put in your radiator to clean out the rust. Has anyone tried this?

Might be hard on water pump seals, heater valves, and composite gaskets.

Don't know the boiling point and how it changes under pressure, but it's used in food processing so it should be safe for seals, valves, etc.

Flush the radiator. add your phosphoric acid and fill radiator with water and run till hot.Drain and flush.Add 1/2 box of baking soda,fill radiator and run till hot,drain & flush,refill with 50/50 antifreeze and water.

White vinegar is supposed to be a very good cleaner for rust and crud. Fill with the vinegar, run it a couple of days and drain. Flush good with water.