Filler up.
Pour in 4 gallons of gold antifreeze. Top off with distilled water. I just barely got the 20th gallon of distilled water open when mine was full. But after driving it to town a couple of times, some of the air bubbled out and it took a bit more. Hang on to that last partial gallon of distilled water for later additions.
Finally, that job is done. And it should now be good for at least 50,000 more miles with no coolant maintenance.
By using all 4 gallons of antifreeze, my concentration is about 57 percent antifreeze. That’s good enough for some very cold country.
Options I didn’t use.
If you remove both block plugs as well as draining the radiator, the tap water flush should not require as many cycles to get all the color out of the system. But that is a PITA, so I didn’t even think about it.
If you replace gold coolant with gold coolant, you would do it the same exact way - except your drain water will have a gold or tan/brown tint instead of a green tint.
If you replace green coolant with green coolant, you would also do it the same way, except at the very end you would add 3 pints of supplemental coolant additive (SCA) right after you poured in the antifreeze - before you topped off with distilled water.
If you want the 50/50 mixture of antifreeze and distilled water most experts recommend, then pour in only 3.5 gallons of antifreeze instead of all 4 gallons. Then fill the half-empty gallon jug of a left-over antifreeze with distilled water, and mark the jug "50/50". Then you’ll have topping-off mixture for future use.
