I've got a fair amount of rust in my cooling system water and was wondering what the best way to remove it is. I also have an old can of Dupont Cooling system cleanser like I used to use in the 70's, appears to be oxalic acid. Should I use this, or is there something newer and better. I gave some thought to just repeatedly changing the radiator water, but don't want to do this again for a while. I might add that I had to replace one freeze plug (above the oil filter) and don't relish the idea or replacing the rest.



Thanks,

Don