Replacing radiator coolant -Whoops! Only 1/2 came out??!!

[Muse]

Sometimes one starts out on a quest to save money and it ends up costing more when the job is done.

Right now, you have a mix of old and new coolant. To top it off, you're guessing at the mix ratio. It's your car and if you're happy with the results, I guess that's all that matters.

I'm not guessing at the mix ratio. I know that over 40% of what's in there is new coolant. How much of the old coolant is in there I do not know. But AFAIK, that old coolant is not harmful. What was in there (I have it in plastic gallon bottles) looks clear/clean. It's what's in the new coolant that I'm counting on to prevent corrosion. I'm no expert, maybe someone will counter my thinking, and I'm certainly interested in hearing accurate information.

 

[Kaervak]

I don't understand the distinction. Aren't both drain and flush?

Do you mean doing one with the engine running when flushing and the other without?

Sorry, should have been more clear. If you're just draining the radiator by removing the hoses and flushing out with a garden hose, use the 50/50 mix. If you're also draining/flushing the block/heater core along with the drain/flush of the radiator then use 1 gallon of full strength and after that's in, top off with distilled as necessary. That will get you a little higher than a 50/50 concentration. You can buy anti-freeze testers at any auto parts place, but I recommend going with litmus strips instead as the tiny tiny gravity testers just don't seem up to snuff to me. You can also use a multimeter to test the coolant. http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=905034

 

[Muse]

Sorry, should have been more clear. If you're just draining the radiator by removing the hoses and flushing out with a garden hose, use the 50/50 mix. If you're also draining/flushing the block/heater core along with the drain/flush of the radiator then use 1 gallon of full strength and after that's in, top off with distilled as necessary. That will get you a little higher than a 50/50 concentration. You can buy anti-freeze testers at any auto parts place, but I recommend going with litmus strips instead as the tiny tiny gravity testers just don't seem up to snuff to me. You can also use a multimeter to test the coolant. http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=905034

Thanks for the explanations. I like the multimeter idea because, well, litmus paper is kind of simple, right? Acid or basic. Plus, I'm color blind, well, total green blind (no green cones in my eyes). I could probably figure out the litmus thing, but I have many multimeters, including a couple pretty good ones. I may have some litmus around, but I'd have to look.

I didn't remove any hoses from my radiator, tried to figure out the plumbing in there but a lot of it looks very mysterious to me. The Chilton's didn't help a hell of a lot.

A few years ago I brought a couple of small bottles of radiator fluid to my mechanic who just did litmus tests on them and told me they were marginal, i.e. some day soon I should replace the fluid. I got rid of one car and just now did the job on my other, saving me the $100 he would have charged. I don't see how you could tell the fluid was marginal with litmus. I thought it either registered acid or didn't.

 

[Kaervak]

They're not exactly litmus strips, but the concept is the same. I've never used them, but I don't see any reason they wouldn't work. Here's a far better explanation of them: http://www.gwrauto.com/RadStrip1.htm