quote:
Originally posted by Stinky Peterson:
I have also seen Drano used to clean a system. The person had to remove the lower radiator hose to get out the large pieces of scale and rust that came out. I can't say I would recommend either one as both are very aggressive.
Drano (actually a generic made up by someone and put in a unique can with an AMC part number on it) was used by AMC in the mid-60s.
This was used not as a full-system flush but as a radiator cleaner. You disconnected the upper and lower radiator hoses, capped the bottom, poured the cleaner in, and filled the radiator with water.
After an hour or so you flushed the mess out.
The big difficulty was avoiding getting any of it on the various aluminum parts, including the grille, that it would eat alive.
AMC had moved over to "Dowgard", a full coolant system fill, that supposedly provided a very long life. It was an ethylene glycol/distilled water mix with a blue color.
As GM found later with DexCool, people let the system get low, topped it off with water from a pond or tap water, added other coolants, and so on.
When they did the result was whitish deposit with the consistency of granite that completely plugged the radiator. Sending the radiators out was very expensive, so AMC decided to try a cheaper solution (pun intended).
It worked about 40% of the time. Many radiators still had to be sent out for cleaning or replaced.
BTW, I've used TriSodium Phosphate to flush systems. It purges the system of a lot of crud, doesn't leave a residue, doesn't suds or foam, and is not too hard on the various metals, rubbers, and plastics if you keep the concentration low and fully flush the system afterwards with clear water.