Clean radiator, cool engine, coolant PH, flow, fans, shrouds.

So, an update on the citric acid soak of my radiator above. 1/2 pound in a gallon of water did not do jack SH*T. It fizzed on the concrete driveway, so I figure it is strong. So, this evening I filled the radiator full of straight muratic acid. I vaguely remember the seller telling me they ran radiator stopleak in it for some reason and I am wondering if stopleak is impenetrable concrete.