
Originally Posted by
EVO-V
If its just a flush all you need are those radiator flushes.
If you're trying to get rid of rust, meaning solid particle debris, you will need to attach a mesh filter to your radiator inlet, run it for a a few days, then clean it out. Repeat until you're satisfied.
This is applicable for older engines.
If you're trying to get rid of rust as a whole, you'll need to be more diligent in your coolant replacement or use a waterless coolant altogether.
Do take care of how you dispose of your used coolant.