First coolant DIY flush @ 49k (very long read, sorry!)

[jkm311]

So, I just made a mess doing this, but I think everything went well enough. I only drained from the radiator, not the block. After draining as much old coolant as possible, I kept the plug out and began filling distilled water into the system. The pink stream emptying from the bottom of the rad. began to dilute, which is obviously good. Nearly clear!Plugged the radiator up after everything stopped dripping out, then kept filling in more and more distilled water 'til I got just below the "full" line on the reservoir. Closed the coolant caps, ran the engine, with the heat on hot (prompting the fan to engage 3-4 times), then shut her off. Once I let the engine cool down for about 30 minutes, I opened everything up (with minimal hiss escaping out of the cap). Now for the moment of truth. I unscrewed the radiator drain plug, and pink began emptying! Good. By letting the engine heat up with the distilled water, it was able to get quite a bit more of the old coolant from elsewhere in the block. Ran some more distilled through, just for posterity. It went from pink to clear very quickly. Plugged the rad. drain back up, then began to fill with the pink Toyota Dealer 50/50. Started her up after only getting about 2.5 liters in. Let the burping commence! Sure enough, she was burping very easily, with me topping off as much as I could. Then, I drove her around for 15 minutes, turning on the heat, then AC (gotta make sure it works!), etc. Got home, and popped the hood. The reservoir was down to half way between low and full. Good. It's circulating and needs a top-off. Of which I only got another 1/4 liter in.NOW HERE'S MY QUESTION: I read that the coolant system in the base 1ZZ is capable of 6.5 liters of fluid (or something close to that number). I don't feel like enough 50/50 is in my system now. I know I only drained from the radiator, not the block, but I want to know I am getting enough in there. Any other way to know, other than topping it off the next few days? I only have just over 3 liters in!

[jkm311]

Bump!Anybody able to comment on my original post question at the bottom? I haven't needed to top off the reservoir in the past two days, but I only managed to get 1 gallon of 50/50 in. Still seems too low to me, considering the 1ZZ can take 2 gallons worth of fluid. Could there really be that much distilled water in there from the flush? I don't want my ratio of coolant to be too low this summer. The good news is I drove across the state this past weekend, just after performing this flush, and no issues at all. I even made a point to pop the hood immediately after 2 hours of driving, and the reservoir was perfect then, and 3 hours later after she cooled down, I only needed to top-off half a quart or so.Any advice would be greatly appreciated. Danke.

[Water boy]

When you drain the radiator there is always fluid left in the heater core and block. That fluid dilutes whatever you poured in. There is only 2 times using 50/50 is acceptable:A) Topping off the overflow tank.B) Filling up the cooling system that is completely bone dry.When you flush the cooling system and the only thing left is clear water in the heater and block, THEN you add 100% coolant that equals 50% of the cooling system capacity. ( If you want 50/50) THEN you top off whatever room is left with clear water.Is this the answer to your question?

[Atomicpunk]

Go to the auto parts store and buy a antifreeze tester. It will tell you what the freezing/boiling point of the coolant is. A 50/50 mix should be good for around -34 f. degrees in the winter. If the mix you have in there now is lower than -34 add antifreeze, if it's higher add water. You may have to drain some coolant to get the right mix.

[jkm311]

Quote, originally posted by Water boy »Is this the answer to your question?But if I am only using 50/50, it's already half diluted, right? So the fact that I only got under 4 liters in makes me think I'm WAY under the amount of coolant I need.Quote, originally posted by Atomicpunk »Go to the auto parts store and buy a antifreeze tester.This sounds like the best solution for me, at this point. Thanks, folks!