Capacity is ~3 gallons (11.7 quarts to be exact). Buy 2 gallons of coolant (not 50/50 mix) and 8 or so gallons of distilled water. When you flush through, do your final flush with about 6 gallons of distilled water. Then drain it out as best you can. Dump in 1.5 gallons of straight coolant. Then top off with distilled water. You should be left with a half gallon of both distilled water and coolant. Pour the distilled water into the coolant and use this to fill up the overflow bottle after cleaning it.

Also, take the time to replace the thermostat and radiator cap. Stant caps are what GM recommends (funny isn't it). Also, inspect the hoses for any abrasions or signs of aging. Replace it now so you don't have to later on.

I have used the yellow prestone without any problems in the past - Prestone All Makes All Models Extended Life coolant is dex compatible so you don't have any mixing issues if you don't get it completely flushed out.

Hope this helps!

 

I came across this thread during a web search. After reading all of it in its entirety, I had to register just to share a few things...

Dex-Cool is ethylene glycol (EG) coolant just like G-05, old-type green coolant (what Prestone use to make), and new-type green coolant (what Zerex green is which has lower silicate levels than the old Prestone coolant). Japanese coolant is also EG. Prestone did make a propylene glycol (PG) coolant, but it is not all that much better for the environment than EG. PG doesn't work any better than EG or vice versa.

Old-type green and new-type green coolants are EG IAT (inorganic acid technology) coolants. Old-type green had a heavy load of phosphates and silicates. Even if you could find old-type green, I would STRONGLY recommend not using it as a Dex-Cool replacement. Zerex has improved it by using less silicates and increasing its service life to 5 years/100,000 miles (which I call new-type green). The new-type green is an excellent replacement for Dex-Cool.

Dex-Cool is an EG OAT (organic acid technology) coolant. It contains no phosphates and no silicates.

G-05 is an EG HOAT (hybrid organic acid technology) coolant. It is somewhat similar to Dex-Cool but it differs in some of the inhibitors used and that is contains silicates. The silicates make it a hybrid.

Most Japanese coolants are also EG HOAT but use phosphates instead of silicates.

The green Prestone All Makes All Models, the green Wal-Mart SuperTech, and the Peak Global coolants are all formulated EXACTLY like Dex-Cool. The reason they don't advertise as Dex-Cool is to bypass the licensing fees they would have to pay to GM. In order to do this, they are dyed green, gold, and other colors.

Dex-Cool does eat gaskets. One of its ingredients is 2-Ethylhexanoic Acid (aka 2-EHA) which is a plastic softener. A study confirmed Dex-Cool eats silicone and nylon...

http://www.imcool.com/articles/antif...l2007Part3.php

"Those companies included heavy duty manufacturers Caterpillar, Cummins and International. He authored two technical papers, derived from thousands of hours of testing, focusing on the effects that DEX’s corrosion inhibitors have on rubber and plastic gaskets and seals, including GM’s IMGs in question. He concludes that the two are incompatible because DEX OAT inhibitors degrade both silicone and nylon, of which these gaskets are made."

The above link also has information on the class action lawsuit against GM in regards to Dex-Cool which is now happening is Missouri.

The old-type green coolant Prestone use to make is no longer made and cannot be found in stores. THANKFULLY, Zerex makes a new-type green coolant which has a lower amount of silicates so it is ideal for both automotive and diesel applications. The new Zerex green coolant also lasts 5 years/100,000 miles...

http://www.valvoline.com/pages/produ....asp?product=8
http://www.valvoline.com/products/zerexoriginal.pdf

Shell also makes a green coolant that sounds like it is similar to the new Zerex green coolant, but I cannot find any info on it in regards to how long it lasts...

http://www.shell.com/home/page/us-en..._products.html (This is for the pre-diluted version)
http://www.shellusserver.com/products/pdf/Shellzone.pdf

Zerex also makes G-05 which is what Ford and Chrysler have been using for the last few years. John Deere has used it for a long time and even recommends using it in equipment going back many years. Mercedes-Benz has also used G-05 for a long time now...

http://www.valvoline.com/pages/produ...asp?product=10
http://www.valvoline.com/products/zerexg05.pdf
http://www.deere.com/en_US/parts/par..._coolgard.html

Ford G-05 is gold, Chrysler G-05 is red, John Deere G-05 is green, and I am not sure what color Mercedes-Benz uses.

G-05 can be used instead of real green coolant. It is really your choice between real green coolant (Zerex) or G-05. I usually use Zerex green in everything I own as it is easy to find in my area. I personally will not use Dex-Cool.

Here are some picture of Dex-Cool mud/slime from a car I worked on a few years ago. I converted it to the Zerex green coolant and it has no problems since...

http://www.freewebs.com/btjustice/pi...2003%20001.jpg
http://www.freewebs.com/btjustice/pi...2003%20002.jpg

I have yet to see the new-type green and G-05 coolants do what Dex-Cool did to the cooling system pictured above.

I cannot argue against the fact that the vast majority of GM vehicles with Dex-Cool have never had problems from it, but those who have do get the mud and/or leaks. I believe the mud forms when air gets into the cooling system when it is run too low and forms rust. The rust circulates in the cooling system and causes more problems.

It is also interesting to note that particulate matter seems to float at the top of the radiator in Dex-Cool systems but sinks to the bottom of the radiator in G-05 and in real green coolant.

I also think there are design flaws in most GM cooling systems. Plastic crappy head gaskets and crappy radiator caps have already been mentioned. But also the overflow tank is poorly designed. The lowest point of the overflow tank (which should be pressurized BTW with a pressurized cap and be connected to the radiator with a bigger rubber hose that has no cap on the radiator) should be higher than the highest point in the rest of the cooling system. This insures the cooling system is truly full and gets most of the air out it. Yet GM continues to use unpressurized overflow tanks that sit lower than the top of the radiator. The overflow tank can show a properly filled level but the radiator can still be very low on coolant. The radiator neck the radiator cap connects to also stupidly sits at an angle. This angle is why the original radiator caps don't seal correctly if they become clogged which is easy to happen when positioned at a angle. The Stant replacement has a spring which pretty much corrects this but it is not perfect. The neck should be straight up and down if GM continues to use it, but they should really move on to a pressurized overflow tank.

So if you want to abandon Dex-Cool, the Zerex new-type green coolant is an excellent choice. G-05 will also work.

No matter what coolant you run, keep on eye on the levels both in the overflow and the radiator.

I personally like to drain both the overflow and radiator once every year and fill them back up with a fresh mix of coolant (55-60%) to distilled water (40-45%). Never use city or well water!!! City water contains haloacetic acids, trihalomethanes, chlorine, barium, chromium, fluoride, nitrate, selenium, and sodium. Well water has even more crap in it. This is why scale forms in cooling systems. USE DISTILLED WATER!!! De-ioned water and de-mineralized water are also considered to be distilled.

Hopefully Helpful,
BTJustice

 

That is a very well thought out post. Thank you!

I will 'clarify' your statement that Dexcool 'eats' gaskets though. As a plastic softener, it truly does not eat the gasket. As the over molded o-ring material softens, it also expands which in turn breaks the weakest point in the gasket frame. As time passes, a leak forms and the cooling system is compromised. The deformation of the frame due to excessive torque severely shortens the life of the gasket as well. The nylon carrier GM used has issues with the water in the coolant as well as what it might come in contact with from the environment during operation.

I think we all can agree that GM dropped the ball on the choice of materials for its intake manifold gaskets. These same materials have shown degradation on the same order with the use of common EG replacement green coolants which is somewhat expected through what BTJustice posted above about the formulations of EG coolants recently.

Through reading Prestone's white papers a few years back, they played their coolant off as the best of both worlds with additive packages with higher silicate levels. Now maybe that isn't so true. I'll have to look into that a bit further.

I do know that Zerex makes a great coolant, but it isn't always the easiest stuff to find. Although I am seeing it around on shelves more now. It has always worked flawlessly in all of my dad's JD tractors.

As I have stated throughout this thread, I am no fan of Dexcool, but this discussion would not have garnered anywhere near the response that it has if someone didn't play the role that I did.

It is nice to see that IMCOOL.com is keeping this stuff together. For the longest time all of their information was so scattered and hardly legible that you couldn't make sense of it.

 

Thanks man. It has been a topic I have researched and have dealt with for almost 10 years now. The Zerex new-type green and their other coolants are somewhat hard to find. We have a few Farm & Home Supply stores in my area and they all carry it, but you will not find Zerex at Advance Auto Parts, O'reilly's, or Wal-Fart which sucks, but I think more and more people will discover that there is currently no such thing as an All Makes All Models coolant. You could probably order Zerex coolant directly from Zerex/Valvoline.

As I stated earlier, Prestone and SuperTech are both Dex-Cool clones. They have the exact same formulation. They are just dyed green instead of red to bypass licensing fees for the Dex-Cool name. Just as a rule of thumb, Dex-Cool, G-05, real green, and Japanese coolants are all about 95% EG with 2% distilled water. The remaining 3% is the dye and inhibitor package used. The reason coolant needs to be changed is due to the inhibitor package wearing out or the coolant failing (Dex-Cool mud) or the need and/or desire to do it arises.

Most diesel truckers run a fleet formulation that is actually similar to the Zerex new-type green coolant that has an added inhibitor package put into it. They will run it 300,000 miles then simply pour in a new shot of this certain inhibitor package without flushing out the cooling system and keep on trucking for another 300,000 miles which is when the cooling system is typically flushed out in those trucks.

Zerex also makes a special formulation for the Navy Seals for the boats they use on their covert missions. Pretty cool huh?

 

Earlier last week, I flushed Dex-Cool mud from 2003 Chevy S-10 with a 4.3L engine. I replaced the Dex-Cool with John Deere Cool-Gard which is a G-05 formulation dyed green. It also has SCA already in it. So far everything is great with the Cool-Gard.

http://www.hitachiconstruction.com/e.../coolants.html
http://www.deere.com/en_US/parts/par..._coolgard.html
http://www.deere.com/en_US/parts/par...mparisons.html

 

i had black rocks(yeah i was that bad) so bad that the guy at he shop had to do a flush for free (79.00 usually) TWICE, i then when i got home i removed the overflow tank and dumped a verity of soaps in it scrubed it out with a wirebrush then completely rinised it out with a hose, and put fresh coolant in, then a day afther i had to clean it agatn probly becasue of dirt that fell of when it was running afther that id manged to stay its orgional color

a menchix had one told me that it was a common problem with chevy, and soon other poeple id as well

so alhtoough it says you dont have to chage it for 150Kmile i recomend checking the state of it with each oil change (every 3,00 miles) and if its getting brown replace it,

ive used both reg and dex cool i think no matter what you use just makesure you change it when it starts to become brown

 

I'll keep it simple:

1996 Impala SS, bought new, Dex-Cool bad within3 years (30K), soldImpala at 71K miles
1999 Corvette, bought used, 73K miles, Dex-Cool looks great
2001 GMC Jimmy, Dex-Cool bad, clogging heater core, flushed, put in Global
1997 Cavalier Z24, Dex-Cool, OK
1999 Malibu, Dex-Cool Ok

BUT, I'm replacing with Global rather than Dex-Cool. I don't have to worry about any ill effects if I don't get all the antifreeze flushed out (mixes with green or orange).

 

I've had bad luck with Dex, at least in the form it came to me in. Got a 1996 4wd 2dr Blazer with ~54k miles in 2004. In the first 1.5 years, the radiator, heater core, and water pump all went bad. The coolant in evey case was dark brown/rust colored and thick sludge, expecially coming out of the heater core the first time we pulled it out (I say "first time" because the replacement heater core had a leak in it also, that was a royal pain to replace it TWICE). The fluid was replaced with green, and the cooling system hasn't had any more problems since. It's just passed 125k this week (including driving from North Carolina to Idaho and back this past summer). I just find it hard to believe that the radiator, pump, and heater core all failed like that, all in very quick succession, without a system-wide problem. I have no idea of the maintenance history of the car before I got it, but could maintenance alone have really been THAT bad as to result in failure in only 60k?

 

Found this thread while researching Dex Cool issues, and thought I should post my findings.
While I don't have have a Blazer, I do have an 2004 Trailblazer with the 5.3 L V8, and an 2001 Silverado with the 5.3 L V8 as well.
I Also previously had a 97 Silverado with the 5.7 L 350, with Dex cool.

I just today drained the Dex Cool from my 2001 which has 98,000 miles on it and is 7 years 8 months old.
There was nothing but clean orange Dex Cool that drained into the bucket.
I also inspected the hoses, and found nothing but clean rubber surfaces. (Pictures to prove it if needed.)
The inlet / outlet of the plastic radiator tanks were also clean with no residue.
The overflow tank was clean, with a very slight orange residue around the very bottom edge of the neck ( The only area exposed to air...), but the bottom of the reservoir as well as all the other inside surfaces were clean.
As I flushed the block, and the radiator twice with water after allowing a complete warm up , I caught all of the flushed output into the bucket each time and still had no grit, sludge or sediment present, only a few specks of black (Likely plastic flashing from the original manufacturing process.).
As a result of my findings, I elected to install Prestone brand Dex Cool.

I have been inspecting the reservoir of the Trailblazer regularly, and with 4 years and 45K miles on it, have seen nothing irregular to date.
As for my 97 Silverado I traded in at around 90K I never saw anything bad in the reservoir of that vehicle as well.

I have not had the time to read every post on this thread, but has it occured to anyone, the problem could be related to the assembly location and quality of the water used to do the 50 /50 mix. The Trailblazer was made in Oklahoma, and the truck in Canada.

Also both of my vehicles use an aluminum block, heads and radiator. (Not sure of the heater core material.)
Maybe the vehicles effected are using a mix of metals, plastics, and gasket materials that are causing a bad chemical reaction.

I think saying that the problem is solely Dex Cool is like saying one person is solely responsible for our economic problems.
I am not dismissing the problems people have had, but I think something contaminated the cooling systems in those vehicles either during assembly (Water?) or maybe when the coolent level was topped off by some knuckle headed teenager working at an oil change place that wouldn't know the difference between Dex Cool and a Qwest Dex Direct phone book.

I think far too many people assume because that because they are taking their vehicles somewhere for regular maintenance that those places are using both manufacturer recommended and quality products.
I would rather drive another 500 miles on my old oil than go somewhere that uses Fram Filters, and Penzoil oil. That, my freinds I do have experience with as I unfortunately owned several used vehicles that the previous owners were proud of the fact ( And had paperwork to prove it.) they had used Fram filters and Nothin' but Penzoil, and when I tore down the motors to do a rebuild, found what looked like the LaBrea Tar Pits. I also had to use multiple cans of carb cleaner, and vise grips to pull out the lifters from the bores because of all the baked on varnish.

"For all those Lemmings that happily and ignorantly drive their Crappy Ford Explorers and Tortoises, using Fram filters, and Penzoil then don't trade them out before they completly fall apart, I truly feel nothing but apathy, because they don't bother to do their research!"

 

I hate dex cool ive seen many cars cooling systems rot away from it. I just finally got rid of my 00 grand am gt that i went through 2 headgaskets on 1 before 90,000 miles due to lower intake manifolds corroding away making it overheat i wouldnt use it stick with the preston GREEN its the best.