Packard Forum Index » Pre-War (1899-1942)

DuPont use to have a radiator flush kit that was oxalic acid and sodium carbonate. You would get the engine hot and run it for 15 to 30 minutes after adding the oxalic acid. Then drain the system and flush the system with water several times. Then fill add the sodium carbonate and run for 5 or 10 minutes. Drain & fill and re-flush several times.

I used the DuPont kit on a 1962 Chevy V8 about 45 that started running hot. It did the trick the stuff that came out when draining the oxalic acid cleaning step was unbelievable. However, I think that the DuPont kit is no longer available. The kit contained about 2 cups of oxalic acid and a cup of sodium carbonate.