Did I fall short?

[Toploader]

This may sound nuts, but................
Last week while on the lift I had the shop drain the Prestone from the radiator.........they did not want to pull the drain plug from the block as they feared it breaking.............anyway all the Prestone comes out..........and here is where I think I screwed myself.......the shop put back two gallons of anti-freeze, pre mixed..........so can I assume that two gallons of pre-mix is really only one gallon of full strength?.........and if so, I should have poured in two full un-diluted gallons, then add water to top off...........am I correct?

What should I do now, the radiator is full up.

[Brown_Muscle]

NO, you are good. 2 gallons of pre-mixed IS 1 gallon of undiluted. However the final mixture under normal conditions should be 50% anti-freeze and 50% water, just as they added. full strength anti-freeze is actually less effective when not mixed, actually.

[gadget73]

2 gallons of 50/50 is 1 gallon of antifreeze and 1 gallon of water. 2 gallons total of coolant from a radiator drain sounds about right. Brand isn't imporant. I've never bought Prestone because its expensive. I like generic green crap. I never buy the 50/50 either because its too expensive. A gallon of antifreeze and a gallon of distilled water is a fair bit cheaper. I bet the shop buys pre-mix in bulk though, so it doesn't really matter. You just don't want 100% antifreeze in there. It actually makes a fairly crap coolant on it's own. 50/50 is appropriate for most climate conditions found on this planet.

[Toploader]

Gents, I think the stuff they used was private label from Advance Auto Parts.......50/50 mix.
It's also time I changed the the coolent in my Studebaker which has 18 qt capacity, there I put in actual drain cocks on the left and right of the rear of the block............so, after draining all 18 qts, should I just put in 2 gallons of coolent, and fill the rest with water, like I have been doing since 1966?

PS.........If I were back in Miami, I would never put in anti-freeze, rather 100% water a can of water pump lube, and a good 14 pound radiator cap, which would raise the boiling point of water past 220 degrees I believe.

[GM_Guy]

I would not suggest pulling the block plugs at all, unless you already have plans to remove the engine for other reasons. Worst case and you put a lot of muscle into getting a non-compliant plug out, you might just end up with a plug with a chunk of cast iron attached to it in your hand for your efforts.

[Toploader]

GM, years ago I removed the block plugs when I rebuilt the engine and put in radiator drain cocks! That being said, how should I re-fill, with pure or pre-mix??

I would not suggest pulling the block plugs at all, unless you already have plans to remove the engine for other reasons. Worst case and you put a lot of muscle into getting a non-compliant plug out, you might just end up with a plug with a chunk of cast iron attached to it in your hand for your efforts.

[miamibob]

I like the pre-mix for the "easiness" of it but if you are careful with the mixture, it really doesn't matter. Don't need lab analysis for the mixture - just be close and you're done!

[jaywish]

Either way can work. Still you probably should invest in a coolant tester. They are relatively inexpensive and could last you many years. I finally had to retire my 25 year old "prestone" brand tester as the rubber ball degraded. They read the specific gravity of the mix and tells you the concentration. That way you know what you got.

Are you going to flush out the system with fresh water? This will get more of the old stuff out of there but it leaves a little plain water in there making the coolant tester more important.

I use the 5 year stuff now. Time goes by so fast I am really glad I switched to a five year cycle. Also I use one of those label makers to record the next change interval. They seem to stick well to cleaned parts under the hood. Better than I expected.

Also it does not absolutely have to be 50/50. If I lived in Niagara Falls or some other really cold place you can be sure I would make it 50/50. If your climate is a bit warmer a 45/55 mix would be just fine, no problems at all. So it does not really have to be perfect, just in range, unless you live in extreme cold areas. Just a reminder if you mix in more than 50% AF the coolant system does not cool the car as well, a high concentration of AF can overheat your car. Another reason to spring for the tester.

[gadget73]

PS.........If I were back in Miami, I would never put in anti-freeze, rather 100% water a can of water pump lube, and a good 14 pound radiator cap, which would raise the boiling point of water past 220 degrees I believe.

straight water is terrible for a cooling system. Cools better than a mix, but it rusts the inside of the block like nobody's business. Down south, I'd probably run 25/75 just to get the anti-corrosion stuff and the water pump lube. I've seen cooling systems run on straight water, and it ain't pretty.


18 quart total capacity on a Stude, 2 gallons of 100% and the rest distilled water gets you close enough to 50/50. That ends up as 8 quarts of antifreeze and 10 of water. 45/55 is reasonable enough though as a mixture.

[Toploader]

If I can not find DW, then just get five gallons of 50/50 mix, as the water portion is mineral free.......keep the extra in the trunk.

[gadget73]

pharmacies carry distilled water for about a buck a gallon. I got the last 2 gallons I needed at Rite-Aid.

[jaywish]

Grocery stores also carry DW. It is used for steam irons.

[gadget73]

I've gotten it at WalMart before too. Point is, easy enough to obtain. Its not exactly like you're looking for the fountain of youth or something.

[Toploader]

I have read for many many yrs that anti=freeze does not wear out.
Not to sound stupid (it's OK you can call me that I am thick skinned) but what happens to a car if the coolant is not changed in over lets say five years?

I just want to understand the purpose of changing coolant, and how often it has to be done.
I am talking old school, the green stuff, like Prestone, Xerox, etc.

[miamibob]

It can get dirty but it is the additives that "wear out", like the rust preventatives and other goodies added to protect the engine.