i recently purchased an 88 cutlas supreme. two days ago the "low coolant" light came on, i simply put coolant in the reserve tank. which as i know now is not the proper fill procedure. ive been searching the internet and even called the 800 number gm has for oldsmobile owners but no one seems to know how to fill the coolant properly. ive heard it has something to do with the cap on the reserve tank? can anyone help me, im lost and i dont want to damage my car?

Refill it by the cap on the radiator. Or, some cars have one by the thermostat housing. Fill it to the proper level and you shoudl be good to go.

filling the reserve is also a perfectly correct way to do this.

Hi michaelwnegron!

Welcome to TOC! Are you planning to use pre-mixed coolant or are you going to mix it yourself when you fill the resevoir?

I sometimes do either way.

Questions for everyone else:

1.) If one were to make their own is 50% coolant and 50% distilled water usually the standard mix ratio? Also, if one didn't use distilled water and used water right out of the tap, would it make any difference?

2.) How reliably accurate is a coolant hydrometer to determine whether the existing coolant circulating in your engine is still good? I have a theory and I don't know if this is true or not, is when I had checked mine with one, by all indications it was good. But on the other hand, and this is from my mechanic, he explained to me that there's usually acid build-up that essentially happens as the coolant begins to show signs of age. I have a suspicion that this also contributed to my old water pump's death. From that experience, I'm more leaning towards flushing my entire coolant system once a year, irregardless. That way I can be sure I'm rid of any acid content that maybe settling on the bottom.

3.) I had another wild and crazy thought and I think I might be liable to try it. I was a steam propulsion plant engineer in the Navy. We did a lot of boiler water chemistry and basically added phosphates and anti-scaling agents to extend the life of our boiler casings. I often wondered if I made the same kind of treated water mixed with coolant could I conceivably be able to double or perhaps the triple the life of my radiator and water pump?

Thoughts anyone?

Sorry, if I'm hijacking your post, michaelwnegron.

I'm not using distilled water and *knock on wood* everything is ok so far. Been driving it like that for 3500 miles. Also, you can use a hydrometer for accuracy, but what I do is fill a gallon water jug with 50 (or 60 in my case..) percent anti-freeze/coolant 50 water. It's my redneck way of measuring. It is a good idea to flush the radiator once a year. I've actually done it twice, just because the person who owned it before put Dextron mized with regular anti-freeze. Thats a no-no.

And I can't really help you with the phosphates stuff you're mentioning. I don't venture into experimental waters with cars. I use what has worked for a good time.

Does your apology make it any less rude?

I see your point, Norm.