Quote:

Back in the day we drained the system, refilled with clean water and added 5 or 6 tablespoons of crystal drano, Ran it for 10 or 15 minutes then drained again. You would be amazed at what came out.

Russ


I have done that with either muratic acid or CLR. When I bought my van it was really crustified on the inside of both block and rad. I drained the system and filled with H2O and some acid [about 1 cups worth] and drove around, flushed and back flushed it, then repeated the process 3 more times till I was happy with it. Sometimes you have to do it more than once depending on how well the system was maintained to be happy with the results.