Expert Testimony in Dexcool Lawsuit

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Just thought I'd share some expert testimony from the Dexcool lawsuit recently. Here is a link and quotes.

Happy reading !!

http://www.imcool.com/articles/antifreeze-coolant/dexcool2007Part3.php

"Expert witness: DEX-IMG incompatibility well-known
One of the documents is from a 50-year veteran of the gasket and seal industries. A member of the SAE, ACS (American Chemical Society) and ASTM, the latter of which he served on the D15 coolant committee, he states that he was aware of GM’s 3.1 liter, etc, IMG failures well before learning of the lawsuit. He goes on to say that the gasket’s poor design and incompatibility with DEX was well-known in his industry. What brought up the discussions was GM’s adopting DEX in 1996, which of course led to widespread testing by him and peers. 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.

For more specifics, the IMG is described as Nylon 6,6 carrier, 33% glass filled, injection molded, single silicone sealing bead. This man felt the IMG was not a good design to begin with, and then the inhibitors start attacking the weakened carrier. Evidently, because the silicone sealing bead is not molded over onto the carrier, the carrier is in direct contact with the DEX. Tie that in with no compression limiters, needed to maintain gasket integrity (see photo above), to begin with and that, according to the expert, is why the gasket is prone to fail.

Expert witness: HOATs do not degrade gaskets
Interesting, this expert witness went beyond the DEX problem to clarify that different from DEX OATs, HOATs, Hybrid Organic Acid Chemistry coolants, do not degrade silicone and nylon gaskets. The explanation is quite simple; the added silicate inhibitors of the HOAT protect the silicone polymer from the type of degradation it suffers with pure OAT (DEX). (I think I need a Chemistry refresher.)

Expert witness: IMGs should not fail
As another expert witness, the plaintiffs brought in a long time, highly experienced Certified Master Technician who has completed 2000 hours of formal diagnosis and repair training. Along with providing diagrams of the engine components in question, he testified that IMGs normally do not fail on their own; they shouldn’t need replacing unless you’re repairing or replacing an adjacent component. Their failure rate should be zero and he’s never seen just an IMG fail. For this engine, to replace them is a 4-6 hour job and will cost $700-1000."
 
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Quote:
and he’s never seen just an IMG fail


Huh? That doesn't make any sense.

If he's done any work on GM vehicles made over the last 15 years, then he HAS seen intake gaskets fail.
 
Originally Posted By: onion
Quote:
and he’s never seen just an IMG fail


Huh? That doesn't make any sense.

If he's done any work on GM vehicles made over the last 15 years, then he HAS seen intake gaskets fail.


He's saying they don't fail without the help of Dexcool. They weren't inherently defective, just not compatible with the Great Plastisizer -- Dexcool.
 
I own a Land Rover Discovery. They are notorious for failing head gaskets. Guess what type of coolant is recommend in the manual to use? You guessed it, Dexcool.

Those who have switched to "green" coolant or something similar to Global Lifetime have yet to have a head gasket fail, that I know of.
 
Originally Posted By: George7941
Absolutely nothing new here. It is a widely accepted fact that 2-EHA is a plasticizer. NO ONE is disputing that.


Then why risk using it? G-05 (HOAT antifreeze) doesn't damage plastic gaskets.

I hope this gives weight to the argument that even though the Dexcool looks good, it is probably damaging gaskets unseen, and soon or later the damage will surface -- no matter how often the Dexcool is flushed.

So, some of you are spending extra money to keep Dexcool only to risk having coolant problems in the future -- no matter how well you service the cooling system.

I have seen pictures of ruined radiator hoses, and other rubber or plastic parts of the cooling system because of Dexcool.

No gain, but many risks with Dexcool.
 
BTW George, I just noticed that you own a BMW R80.

I had one of those for many years and loved that bike. That is one motorcycle that a person could ride for a lifetime and never regret it. I've always felt that airheads were ridden by the most intellegent, discerning riders on the road because of their reliability, practicality, and useabilty. You won't ever hear an argument from me about owning one of the those.

I got stupid when I quit riding airheads and started riding modern sport-tourers. No personality.
 
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Have you seen any pics of ruined radiator hoses or gaskets or other plastic parts that have been using prestone,peak or zerex extended life anti freeze?
 
It is widely accepted that 2-eha attacks plastics and silicone but this mention of rad hoses deteriorating due to dexcool is news to me. So, dexcool attacks EPDM?

Question that arises is - in over a decade of using dexcool, how come it never deteriorated any of the hoses on my trucks?

BTW I am getting on in age but I still enjoy riding the Beemer. The only bike that is better looking, IMO, is the old MotoGuzzi 750 LeMans from the early 70's.
 
Have you actually looked inside the hoses? I am pretty sure most cooling system hoses are quite thick. Thus, can take a lot of abuse.

But yes, news to me too. :)
 
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Go to my original post and look at the pics. There are several on that website that show the inside of some hoses after Dexcool damage.

BTW, don't some types of rubber contain silicone?
 
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Many people, for one reason or another, might "upgrade" to silicone hoses. This might be done for perceived durability, or perhaps decoration....either way, if they are running Dexcool this would be an issue.
That said, these hoses are usually aftermarket so its not a GM warranty issue, however, the coolant still shouldn't eat through any form of hose.
 
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George:

I had a '72 Moto Guzzi V-7 Sport that I let go and wished I hadn't. This was the bike that later became the LeMans. It was probably the first true sportbike. Once you've seen and ridden one, you would never forget it. They were very fiddly bikes and I got tired of messing with it. I'm looking for a restored Eldorado right now.
 
Originally Posted By: Tim H.
Originally Posted By: lucerne06
Have you seen any pics of ruined radiator hoses or gaskets or other plastic parts that have been using prestone,peak or zerex extended life anti freeze?
I asked a very similar question on this thread:
http://www.bobistheoilguy.com/forums/ubb...969#Post1527969
It has yet to be replied to.


Here is a link directly to a webpage with pictures of hoses ruined by Dexcool.

http://www.imcool.com/articles/antifreeze-coolant/dexcool2007Part2.php
 
I installed Prestone dex-clone antifreeze in my Subaru last fall, and yesterday I opened the cap for the first time after quite a while. The cap had a coating of black particles and flakes, and the overflow bottle had a scattering of black flakes floating in the coolant. When I was using G-05, there was a fine brown/black sediment forming in the overflow bottle, but never any black flakes. The flakes were flexible and soft. Flakes of rubber from the hoses?
 
Sorry to hear of your experience with Prestone AMM EL. Just did a 3 year distilled water flush series draining Prestone from an Altima, and refilling with Peak LL. System was clean as whistle, and the stuff that drained had no visible particulate. Just chose the Peak this time instead of Prestone because of $5 rebate. I'm also Running Prestone AMM in a Tacoma with no issues.

Just wondering when you did Prestone install, did you flush the whole system, of just the radiator?
 
Just drained and refilled, about 2/3 system capacity, with 50% reverse osmosis water and concentrate, since the old G05 was clear and is supposed to be compatible with ELC. The car is over 100,000 miles, though, on original hoses.
 
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