Hi,

I wanted to flush out the dex-cool in my 98 chevy s-10 (4.3L v6), and wasnt exactly successful. I know the people here are some of the most dedicated DIYers, and Ive learned a lot from everyone here, so I hope you might lend some help for a non-mb car.
I wanted to flush out the coolant on my truck. I read about how to do it from numerous places online, so decided to start. I have a petcock on the bottom of my radiator, and didnt want to have to remove any hoses. I did the following:

-drain radiator
-fill radiator, repeat.
-fill again, run truck until fully hot, with heat on full
-drain, repeat
-make input into radiator = flow out petcock, ran truck to full temp with heat on.
-drain radiator
-refill w/ antifreeze

The problem I encountered awas that the system was supposed to be 12 qts, however, I only got ~ 1 gallon out of the radiator. after Id do the flush, Id let itdrain, and that would be clear, but after a bit often some more of the old orange antifreeze woudl then come out, as if it never really flushed when I added the pure water.

The problem really becomes that I dont know how well it flushed, and so I dont know what amount of water and what amount of old 50/50 coolant remained in the block/heater core, as there must be approximately 2 gallons capacity between those two. In the end I added only antifreeze into my radiator, which took about a gallon, then a 50/50 mix into the recovery bottle so it was at the correct levels. I figured the best and worse case scenarios were as follows:
1) no flush of block heater occurred... therefore ~2 gallons of 50/50 old mixture in there, plus my ~1 gallon of antifreeze => 66.6% antifreeze ratio.
2) full flush of system... all old 50/50 mixture was flushed out, 2 gals
water and ~1 gal of antifreeze => 33% antifreeze in sytstem.

I dont really know what amount I have, and dont know if the coolant bottle is a valid place to test after only driving my truck for about 200 miles and 2 days. I cant get a big enough sample out fo the radiator itself, because there is some large metal piece at the opening, so I cant stick the hydrometer tube in deep enough. Any ideas how long itt akes for sufficiant mixing in the recovery bottle?

SInce I dont know how much coolant was in the block/heater, Im in kind of a pickle. Maybe I should have removed the heater hose and pshed water through, but to be quite honest, I was worried about doing that. Also, judging from refilling what I could to get it up to full capacity, even if you got the whole block and heater flushed and so filled with pure water, you cant get enough pure antifreeze into the radiator(which is abot 1/3 the total system capacity) to get the system to be 50/50 ratio, youre at more like a 33%. Whats the solution to this, run at 33% for a few days, drain some out and refill with more pure antifreeze to get it to 50/50?

Id like any advice on what I should do for this situation. I know there is a gallon of good new antifreeze, but I dont know the pH of the system bnefore, which is the major factor on parts longevity. SInce the actual antifreeze to water ratio will be between 33-66% I guess Im safe, but I dont really know. Id liek to avoid taking it to the dealer to do, and Im not too sure about fixing it myself, but any info/instructions would be most appreciated. By the way, the bottom of my truck has skid plates all along it, so I cant really get to the block I dont think, the radiator petcock is the way to drain, plus Id be worried to mess around with the drains on the block anyway.

On one more quick question in this long-winded post, I would like to know about the valkidity of what a lot of online sites say is how to flush a radiator. They say that you:
-drain
-fill with water
-drain. repeat
-fill with a 50/50 ratio

Some clain that you should run the vehicle with the pure water in it, others dont say to. However, if most cars are anything like my truck, that is only really flushing the radiator, which is at best 1/3 of the system capacity. Even if you flush the radiator once every year, it would take approximately 6 years(because of the mixing of old and new) to get all of the original mixture out if only doing a radiator flush. How does this work, are these sites telling me bad info, or am I just really not getting this...
Thanks very much for your help.

JMH

First on running pure water,,, in the old days people would add a lubricant to the water for the water pump... that is now in the antifreeze,,,and also the anti rust and improved cooling call for antifreeze all year in all cars as far as I know.
Many auto parts houses sell a plastic kit which will insert into one of your water lines which will allow you to Backflush your system,,,this is sometimes an advantage...
The lower radiator hose often comes off the engine at a place which, without draining the block , will leave a reasonable amount of water in the system. That would need to be taken into account when figuring how much antifreeze to add.
No , the recovery bottle is not a legitamate place to check the coolant. Check in the radiator.
Why do you think they put drains on the block?
Drain some coolant into a jar and use the hydrometer in it. But you are pretty far north,,, and if a gallon of antifreeze costs less than an engine block replacement I would go out and drain a gallon out again and put straight antifreeze in again.
Good luck... Greg

One thing you could do is pull the thermostat. This valve shuts off the supply to the radiator, and will leave the block full.
This is why the back-flush kit is so popular.
This kit is made by Prestone, and you should find it easily at an auto parts store. It splices into the heater line. EASY

I don't recommend you run straight coolant though, unless it is super cold. Follow the directions on the bottle, as this coolant is a concentrate and is meant to be dilluted.

Normal usage is 50/50, and this is where it cools well.
BTW, straight water is the most effecient coolant, but has no lubricant for the water pump. There used to be a lube you could buy, but haven't seen it in a while.

If you are overheating, it is not a problem with your coolant, but something else, like not having your aux fan come on.

Personally, I use the newer orange coolant!

__________________
Ed
1981 300CD (Benzina)
1968 250 S (Gina) 266,000 miles!
1983 Alfa Romeo GTV6 (Guido)
1976 Jaguar XJS-saved a V-12 from the chevy curse, what a great engine!
1988 Cadillac Eldorado (better car than you might think!)
1988 Yamaha Venture (better than a Wing!)
1977 Suzuki GS750B
1976 Yamaha XS 650 (sold)
1991 Suzuki GSX1100G (Shafty Gixser)
1981 Yamaha VX920RH (Euro "Virago")
Solex Moped
1975 Dodge P/U camper


"Time spent in the company of a cat, a beer, and this forum, is not time wasted!"

I was not suggesting he run 100 percent antifreeze because water is needed to activate it. I was figuring from his math that the original gallon he added was diluted with water in the block, so if he drained one gallon out ( the amount he mentioned coming out when he used only the radiator drain ) of diluted antifreeze, then replaced it with straight that he could figure on being closer to the 50/50 he needs...Greg