Originally Posted by marif
Guys, thanks much - I'm goin to do it this wk-end. Thanks Phil for taking the time for the writeup.
You're quite welcome Marif. Weekend is about right - it took me all weekend to get 6 dumps and refills done, allowing time in between for the engine to cool off. I bought eight 4 liter (4 quart) jugs of distilled water from the grocery store for the dump/refill procedure and for the final mix. It was a lot of time but at least I know that I really did replace all
It might seem a bit overkill, but here's how the math works and this is why you don't just drain the rad once and then refill.
Total volume = 9 liters
Volume drained from rad = 4 liters each time (measured), Includes sqeezing hoses and blowing into the coolant tank (yea, yea - I know).
1st refill with 4 liters distilled water. % of original coolant remaining = 55%.
Run engine until hot to ensure thorough mixing, then let cool before the next step.
2nd drain/refill with 4 liters distilled water. % of original coolant remaining = 30%. Same again - run the engine (drive around the block a couple of times, then let cool before proceeding).
3rd Drain/refill. % of original coolant remaining = 17 %
Run engine for mixing and then cool.
4th Drain'refill. % original remaining = 9 %
Run engine for mixing then cool.
5th drain/refill. % original remaining = 5% ( 95% distilled water + 5 % old coolant). Run engine for mixing then cool.
6th Drain - removes 4 liters of 95% water + 5% old coolant. Then add 4 liters of straight undiluted new coolant
, which happens to be one full jug. Resulting mixture = 44% new coolant + 56% water (close to the typical 50/50). This is good enough to drive with.
Next step to get up above a 50/50 mixture, is to drain just 2 liters (quarts) of the new 44% coolant mixture and replace with 2 liters of straight undiluted coolant. This gives you a mixture of 56% new coolant. You can do this anytime convenient - next day, next week, whatever. Note that this requires a second jug of coolant. But it leaves exactly half a jug of new coolant, which you then mix with 2 liters of distilled water, and you now have a full jug of 50/50 coolant to keep in the garage for top ups during the next couple of years.
If you want a stronger final mixture than 56%, drain a full 4 liters of the 44% coolant mixture and replace with 4 liters of full strength undiluted coolant. This yields a 68% final mixture - or the basic 70/30 mixture for maximum freeze protection.
But note that even though the freeze protection is better and the additive level is higher, a 70/30 mixture is actually a poorer cooling medium than 50/50 ( and straight water is a better cooling medium than any mixture - but we can't run with that). If you live down south, a 40/60 or 50/50 mixture is all you need. If you live in northern Ontario or in Manitoba, you need the 70/30.