1980 with the original style copper radiator, green coolant. Dewitts recommends HOAT (Zerex G05) for there radiators. I use the Zerex in other vehicles, no problems.
My concern is flushing the green out sufficiently to avoid problems with the HOAT. No matter how well I flush the system, most likely there will remits of the green. Do I make the switch or stay green?

 

Why the zerex? What's different about it? Why isn't it compatible?

 

The Zerex is a HOAT and it's basically about compatibility with the aluminum. Actually, Dewitts has three coolant brands to select from on the information sheet on their website, the Zerex was just the first on the list.

 

Wow, didn't even see that, lol! I've been running "Peak".

 

me too.

 

Same here...green coolant for years now with my Dewitts, and the radiator core looked great during the drain for the 2014 rebuild of the L-82. Would not argue with the manfacturer's recommendation but just about all coolants today are used primarily with aluminum radiators so not sure about using a HOAT coolant for an aluminum Dewitts unless he uses an "exotic aluminum" in his builds which I highly doubt. I am certainly not sweating my green stuff in the radiator for the last 10 years....Change the coolant every 5 years or so and you should be good to go.

 

Conventional or traditional green antifreeze is considered an IAT or inorganic additive technology which supposedly uses up it's additives after two years. The OAT and HOAT contain organic technology. Jeep/Chrysler has used a HOAT for many years.
Regardless, If I stick with the green, I'll just flush it every 2-3 years. I was hoping somebody went thru the process of switching to the Zerex and if it presented any issues.

 

The way I do it. Drain 1st of course.

Refill with distilled water. Run the engine until hot. Drain again and repeat until the water is clear. Use a white bucket to confirm.

 

Thanks

Did you switch from the green?

 

Just an FYI that just about all of the traditional green coolants now prominently display on their gallon jugs, "5 years or 150,000 miles" including cheapo Supertech from Walmart. I generally change the green stuff every 5-6 years, Dexcool every 5-6 years, and for my Chrysler 300 the Hoat every 5-6 or 100,000 miles. The Chrysler branded HOAT that I have in my garage getting ready for the next timing belt change states prominently as well on the jug, "5 years or 100,000 miles". They are ALL about the same and all work.

I changed out the radiator on one of my DD, the 01 grand prix, at 180,000 miles after leak developed...Dexcool for the first 60,000 miles and then Green coolant until today...200,000 miles on the motor.

My 94 Mustang GT with 32,000 miles on the car still has the OEM aluminum radiator and has used Green coolant for all of its life..bought new.

Use Distilled water and green coolant in the Dewitts and change it every 5 years or so and you will be fine. no need to create extra work for yourself...I have found consistently over the last 35 years working on cars, the service/change interval generally (not always) is much more important to the longevity of most parts, then the actual fluid used during the service.

 

If you've been working on cars for 35 years, I am sure you have come across gaskets eaten by Dex Cool. I don't thing I would say that DexCool and Hoats are the same. If I remember correctly, GM got sued because of damages caused by DexCool. I don't remember the additive in it that caused the problem. Anyway, I just spent a large amount of money on a radiator (compared to other radiators) and I don't mind doing a little more work to protect the investment.

 

I replaced my radiator with a Dewitt this past summer. I did the same as above until it was as clear as I could get to fill two 5 gallon buckets. It had the green stuff and I switched to Zerex G-05 (as recommended by Dewitt's website). I've only ran the car for 1/2 a summer...no issues.

 

Yes that is correct about Dexcool. Notice I said I switched the 01 grand Prix from Dexcool to Green coolant at 60,000 miles. GM still does use the Dexcool and the issue was the type of engine gaskets that GM initially used with the dexcool...they switched gasket types later. I just did the LIM gasket (GM's was plastic) on the GP in November 2016 at 190,000 miles and the gasket was bulging but not leaking. The Felpro replacement gasket is plastic with a steel core and most never have an issue after the exchange. My 10 C6Z06 still has Dexcool but I will probs switch the green stuff when I upgrade the LS7 heads this summer. Definitely not a fan of Dexcool but considering GM still uses it in million of cars, it is probably OK today.

I still think my Dewitts in the 78 C3 with green coolant is fine, as I stated, and observed in 2014. That radiator is now 10+ year old and zero issues with the green coolant.

And this from a very reputable guy on the Z06 forum:

"Those lawsuits are crap. By the way you can sue over anything but that doesn't mean you have a case or that you even win. I haven't heard of GM paying one cent toward those law suits other than defense costs.

I have been using Dexcool since I got my 97 Corvette back in 97. Over the years since I have had owned 7 cars that had Dexcool. Four of them went the 5 years before changing coolant with no issues. It looked like the day it was first put in the car. One of those four went through a second 5 year change with no issues with the coolant. Again it looked like new when I changed it. My 03 Tahoe is coming up on its second 5 year change in Dec of this year. Probably will change a couple months earlier so I don't have to do it in the cold. Coolant still looks like it did 4+ years ago when I put it in.

It is in millions of cars and not causing problems. You can read the lawsuit info on the web and see the whining type of person who is involved and you can look at actual trouble free results over many years with millions of cars. Do you side with the whiners or the facts?

Bill "

 

Yes I did. No issues after the swap. Make sure you have the heater on to flush the heater core too.

Don't burn yourself and take you time.

 

There are two drain plugs, left and right, in the bottom of the block about the middle. If you want a good flush, remove these plugs and drain the old coolant. Reinstall the two plugs, fill with water and then remove the plugs again to drain. That should give you peace of mind that it was flushed good. Remove hoses for the heater core from block/water pump and stick your garden hose in one end and flush. I think you have the rad figured out.

 

EXACTLY!!!! Without draining and flushing out engine block and heater core...you are doing it only part of the way.

Not that it make any difference...and most people will not do it due to the costs involved....BUT....Check out Evans coolant. See for yourself.

http://www.evanscoolant.com/?gclid=C...FZUkgQod60cEyg

Check out the video with Jay Leno.

DUB

 

Pull the block drains, one of the heater hoses, connect your garden hose to the open heater hose, put the radiator cap back on and turn on the water. You could even pull the thermostat if you're feeling real frisky.