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Bad A/C Delco Waterpump. 91 Eldo 4.9 Anything better than AC Delco Waterpumps?

20K views 80 replies 11 participants last post by  eldo92 
#1 · (Edited)
Well, lately every Delco part I've bought either through the dealer or authorized Delco Distributor has gone bad within a few months. A Delco EVAP, a Delco Powersteering Pump that whinned immediatly, and now my Delco Water Pump has a very subtle droaning noise to it. Only 1.5 yrs old with 10k miles on that pump

I noticed a slight change in the engine sound/harmonics the other day(something no-one else could pickup) so I checked all accessories with a mechanics stethoscope and the water pump/bolts definitely are transmitting some harmonic noise. Not so much the pump housing because its probably isolated by the internal pump seal or somethng, and the block is silent where the bolts attach.

Someone once told me to see if the GM parts were still available when replacing any part as they are better than Delco like when my P.S. Pump failed. I think Delco P.S. Pumps are remaned anyway from Delco.

I'll have to check to see if they still make GM replacement pumps.

Does anyone remember seeing a post/thread about a guy who was discussing a different brand of a better quality water pump for a 4.9?

I thought it was here or maybe on the Fiero Forums. Can't remember but I think it was someone doing a 4.9 buidup and he named a water pump in his build/mod list and I had the the feeling that he was making a point that this other pump was better for some reason or rational.........................

So to add insult to injury, when the injectors were replaced, I decided to get a new Delco P.S. Pump to replace the original pump, and while everything was appart, why not replace the original GM Waterpump Too as the car has 89k ml.!

I also purchased a new Gates tensioner at that time but I didn't like the looks of it so it never was installed, but the original tensioner spring sprung this summer so the Gates went on after I called to inquier about the narrower body. Gate's confirmed that the tensioner has a better designed tension spring which is why its narrower. I'm now wondering if the original tensioner cause any stress on this pump which I also put on a new pump pulley due to an old issue.

I hate going by the old saying "if it ain't broke don't fix it" but it was the logical thing to do............

Anyone else having problems with AC Delco Water Pumps?

Thanks,

chris
 
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#31 ·
My experience with Optima, not that good. I'd just try a different brand the next time besides Optima. And yes, the most recent Napa batteries I bought for a fleet of trucks and construction equipment were crap. Bought a batch of AC Delco from a battery only vender and even some from Auto Zone and have had no problems with them.
 
#33 · (Edited)
:bonkers:SORRY FOR THE LONG POST AGAIN, BUT THIS IS DEFINITELY WORTH THE READ.....


Well, after all my research to find a better water-pump,my 2nd and new "Cardone Select" water-pump failed within 1yr. 2 months with less than 5000 miles on it. I even did a very aggressive flush using the old GM Oxalic Acid flush/neutralizer procedure and according to the GM TSB to be sure the system was very clean and installed a new rad. I then used conventional EG Green Coolant and Royal Purple "Purple Ice" coolant additive/lubricant.

I really thought the Cardone Select new pump would be the best after they issued a very specific TSB about this pump and speaking to 3 Cardone Techs about the pump design.
Here it the new TSB link as the old links I posted are no longer active:
http://my.cardone.com/techdocs/PT 58-0008.pdf

CARDONE wants me to send in the pump for "Lab Analysis" to determine why their pump failed, but I'm sure I won't get a straight answer of what the results are.

I even installed a 2nd new GATES Tensioner with this pump because I thought the other new tensioner was over-tensioning the drive belt system and other components to make my old Delco pump fail within 1.5 yrs and under 10k ml.

I may do some sort of a torque ft. lb test comparing the Gates Tensioner to a new Delco Tensioner just for the h'll of it. I'm going to buy a digital wrench adapter like this to do a comparsion:
http://www.eastwood.com/wireless-electronic-torque-adapter.html

Or Craftsman, but I think it's discontinued:
http://www.webbikeworld.com/r2/torque/torque.htm

I spoke to Gates today and they insist there is no problems with their tensioners. I just can't understand what is causing the bearing to fail on now 2 different pumps.

I posted this idea before and are now considering it but I have some concerns. I've been talking with Stewart Componants Mfg. who makes an Electric In-Line Pump.
http://www.stewartcomponents.net/Me...OD&Product_Code=E558A&Category_Code=ElectPump

I would re-rout the belt and no longer drive the water pump pulley and go from the Crank directly to the A/C Pulley. I'm just concerned there may not be enough belt surface area to drive the A/C Compressor going from 75% belt wrap around the A/C pulley to about 25%-30% belt wrap when re-routing belt. I'm afraid the belt may slip when the A/C engages with so little contact area.

I sent some photos of the 4.9 water-pump design and wimpy impeller design to a Tech at Stewart and he agreed that the impeller should be removed for better flow if I decide to use their In-Line Electric Pump but he said it may still flow well with it left on. They actually want me to send the pump in to see if they can get a better impeller to fit this pump, but that will not address the bearing/seal issues everyone seems to have.

The other problem is clearance to even get the pump to fit in the area between the lower rad. outlet to the water-pump rear housing inlet............Very little room especially with the tranny lines in the way which can be fitted with braided line, but there may not be enough hose length on each end of the pump to absorb engine movement.

I've got some old injuries and replacing the stock pump again really does me in...............

I wish I never took my OEM pump off with 80k ml. but I was doing other repairs in the area and it just made sense to replace it as preventative maintenance............"so if it ain't broke, don't fix it".....:banghead:

I found others out there who are also having problems with after-market pumps:

http://www.cadillacforums.com/forums/ht4100-4-1-4-5-4/13096-replacing-water-pump-too-often.html
http://caddyinfo.ipbhost.com/index.php?showtopic=1129
http://caddyinfo.ipbhost.com/index.php?showtopic=27639

Anyone else having pump failures when using newer tensioners which maybe the cause??????????? :annoyed::crying:

Anyone having aftermarket pump failures PERIOD?

I wonder if I can somehow verify if pumps in the junk yard are original O.E.'s and not replacements. Does anyone have an old O.E. pump laying around to examine for markings???????

I would rather take a chance on a used O.E. pump than buying any new pump at this rate.


MY WARNING TOO EVERYONE:
DON'T REPLACE YOUR GM/OEM WATER-PUMP IF IT'S NOT MAKING NOISE!
YOU'LL BE SORRY LIKE MYSELF AND OTHERS!
 
#34 ·
My replacement pump looked exactly the same as the new one. I used the old tensioner, old idler pulleys, same pulley on the water pump, same AC compressor, same alternator, same crank damper pulley. I only replaced my water pump because the gasket was leaking, it had 103k and thought for good measure go ahead and replace. My past experience with parts store new or used pumps whether it was water pump, power steering pump, fuel pumps was not good in the past for a fleet of trucks I managed. I started buying OEM pumps and the problems went away. BTW, the pump I bought from a dealer part number was 12369484 and came with a gasket and that part number might have changed. I don't know the price on it now, not cheap then. You might shop around. I only had to do mine once.
 
#35 ·
Chris, to have repeated failures of a water pump is very strange. While I agree that most new parts suck, I have never heard of a single part failing that many times.

I'm in a frustrating situation myself right now. I have an a/c compressor that works fine but is leaking out of a rear plug. I do not want a new one because of the reasons you have given, but can't find the correct o-ring to repair my current compressor.
 
#37 ·
^^^ Ha! You sure are an early bird, Dennis!

It's on the '98 Eldorado. There is a port for a pressure pop-off valve that is leaking. Cadillac doesn't use a valve, it's just a plug... but it is leaking. The good news is that I just spoke with a local Cadillac guru a minute ago and he laughed. Apparently I'm not the first with that problem. :rolleyes: Fortunately he said that NAPA sells a new cap and washer... :thumbsup: Whew! I was not very excited about a new compressor given their notorious track record.
 
#39 ·
4:00? I used to do 4:30. I need to get back to it... Got so much more done! My problem sticking with it was the fact that social activities often went past my 9:30 bedtime that would allow for that kind of wake-up time. :yawn: :coffee:
 
#40 ·
It looks like these pumps are failing no matter what mfg. so they must be sourcing the same Chinese seals/bearings/components. The 1st pump that failed was the more expensive Delco 251-595 / gm#12369484 which is stamped "MADE IN CANADA". Delco also makes the cheaper pump # 252-720{#88926234}. The expensive Delco lasted 1.5yrs. under 10k ml. Now the CARDONE SELECT "improved bearing design" failed at 1yr with under 5000ml.

If you check out *************** links I posted above; other people are also having failures on after-market pumps. In post #9 here, this guy did his pump "4 times and once in the Marriot Parking Lot"!
http://caddyinfo.ipbhost.com/index.php?showtopic=27639

I'm so disgusted..................

chris
 
#43 · (Edited)
I've used Distilled water, heater core disconnected for years as I'm in Florida, new rad. 50/50 Ethylene Glycol Green Coolant and this time around, I used Royal Purple/Purple Ice additive/pump conditioner.

Either its inferior designed pumps, or the new tensioners are made with too much tension. That's my best guess.

My original oem GM pump was still good with 80,000 miles and a somewhat neglected cooling system
I just decided to change it out when replacing other parts and thought it made sense to replace it.

This really sucks..:gah:..:banghead::bricks::bricks: This is a good one::shark:
 
#44 · (Edited)
I found this.........more past members with more bad aftermarket Water-pump replacements:
http://www.cadillacforums.com/forum...orum/215543-water-pump-4-9-a.html#post2990442

Same old same old here:
http://www.cadillacforums.com/forums/ht4100-4-1-4-5-4/168395-4-9-water-pump.html

And here:
http://www.cadillacforums.com/forums/ht4100-4-1-4-5-4/13614-turns-out-i-have-bad-water.html
Maybe the older Delco Pumps were better than the 1st one I bought.

Also here:
http://www.cadillacforums.com/forum...-emergancy-water-pump-replace-went-wrong.html

Another 4.9 water-pump story but with some nice photos.....He used the same Permtex Gasket Adheasive that I also use....... I just wonder how he made out with Crazy Glueing the impeller plate back on. That's a very different impeller design also...........plastic. I never saw a pump like that yet.
http://www.cadillacforums.com/forums/ht4100-4-1-4-5-4/94998-just-finished-my-4-9-water.html

Can anyone say "Class Action against ALL 4.9 Water Pump Mfgs."!!!!!!
This is on my to-do list if I win the MegaMillions!:want::rant2:
I'll teach the after-market.

Hmmmmmmm Hmmmmmmmm Hmmmmmmmmm.
 
#46 ·
Faded Crest: Approx. how old is that Delco Pump you have????

Is it the more expensive Delco 251-595 / gm#12369484 which is stamped "MADE IN CANADA"?
Delco also makes the cheaper "Wong Tong" pump # 252-720{#88926234}.

Any identifying marks on it.............please let us know........very curious?:hmm:

If your's is older that 10yrs old, it may be a better quality pump all around.:yup:

I wish I could find a NOS 4.9 pump in a GM O.E. Orig. Equip. Box. What happened to NOS parts for Cads. of this era????..........all the classic car guys can still get NOS parts. I guess they made so much volume back then and considering the numbers of those classic cars made and still on the road and there seems to still be NOS part available. All were left with is Delco which I've had other Delco parts fail quickly too.:gah:
 
#47 ·
Replacement generic aftermarket pump on my '90 is 5 years old. Purchased at Advance Auto. No problem to date.

Replaced the pump on my '95 in '04 or so with a Delco pump. Bearing failed 2-3 years later. Replaced with generic aftermarket - I sold it 5 years later with that same pump.

Interesting discussion, but just don't confuse gasket leaks with pump failures. These stamped steel pumps are finicky about proper install, and I've seen a number of botched jobs (loads of gooped RTV, stripped 10mm bolts, overall improper torque).
 
#49 · (Edited)
Do you still have the original old "Long Style Tensioner" or the shorter redesigned aftermarket tensioner?

I agree, a gasket leak is different from a contaminated pump seal and weeping a ton of coolant out the weep holes. The weep holes are there to normally drain some coolant and expanding air from seal expansion when hot. If the weep holes were not there, then expanding air pressure with small amounts of coolant would push past the seal.

I also agree with you about the installation......... Only use the better Felpro gaskets, and use the Permatex Gasket Spray Adhesive #80065, 80064, or 80697 on both sides of the gasket surface. No leaks for me, but a pain to clean. Permatex discontinued their old gasket remover #80646 due to the EPA and its really hard to find now but I bought 2 cans last year at Advance that were still on the shelf and were not pulled. That old product litterally melted the old gasket off and burned like hell too if you got it on you......and it reminded me of paint stripper from the burn and ammonia odor. It also stated to not get it on paint. I really think that paint stripper in an aerosol can, found at the hardware store or Home Depot, is the same formula which I'll have to use. I may compare some MSDS 's as compared to the old Permatex product. I heard their new Gasket Remover is not good at all.
 
#48 · (Edited)
Looks like my idea for using a Stewart Electric In-Line Performance Pump won't work. There is just no room anywhere since its required to be mounted close to the rad and low to be gravity fed. I've attached a C.A.D. Drawing in case it could help others with different cad. models other than my 91 Eldo. who may want to do the mod. This would definitely work with the Fiero guys retrofitting our 4.9's into their cars. If I got it to fit, I'd still do a test and run the old pump w/o the thermostat and dumping the water in a 5gal bucket, take a reading of how much water the original pumped moves, then do the same with the electric pump with the original pump's impeller still installed to make sure it meets or exceeds the same volume. If not, the pump comes off and the impeller gets cut off for better flow with an electric pump.

The Electric Pump is 6 1/4" L x 4.5" W at the body and 6 1/4 total width with the top mounted electronic module. This pump is also $400 but I'd buy it if I could make it fit! They make an improved all composite pump with the same dimensions.
http://www.stewartcomponents.net/Me...OD&Product_Code=E558A&Category_Code=ElectPump

Very little room down by the lower rad and rad. oil cooler lines would need converted to braided stainless and re-routed w/ 90deg fittings on the rad. ports. Maybe I'll see if the rad/condensor can be moved forward but I doubt it. No room under the battery because of the cruise control vacuum canister which I may take a closer look at and get rid of it, but having to cut 2 large holes in the wheel well, I may run into the subframe/uni-body.

I thought about even mounting this Elect. Pump in front of the rad/condensor but no room to bring the hoses back around.......I'll have to look again. Mounting it on the drivers side of the engine compartment doesn't look good either because of the rad. fan shroud and the close proximity of the exhaust manifold and pipes but those could be wrapped with header wrap as would the rad. hoses. I always wanted a new performance smaller rad. fan anyway.........nothing is going to be easy and my clock is ticking as this pump is getting loud with every mile.

I did at least confirm through "4 Seasons" who is a major A/C Compressor Mfg. and there engineers said the HR6 compressor could very well be run with only 25% belt wrap like other cars that use the HR6 compressor and our Cads really have over-kill with 75% belt wrap around the A/C Pulley. So by-passing the waterpump pulley with a shorter belt re-routed from the crank pulley to the A/C pulley should would work without the belt slipping when the A/C engages........

Meizere ,another performance pump mfg., makes many different types of Elect. Pumps. Remote pumps and even rad. mounted pumps but you need aluminum tanks to weld on the fitting. This would probably be the best solution with the confined space but a custom rad and this thing would run well over $1000 but it beats changing pumps every 5000ml and yearly!

I wish I could really get into this deeply, but I'm down to my last working car with a ton of back problems to keep screwing around.
http://www.meziere.com/displaycategory.aspx?id=244,381 Rad. Mounted Electric Pump
Styles:
http://www.meziere.com/ps-790-0-WP116R.aspx Remote Elect. Pump1
http://www.meziere.com/ps-892-0-WP136S.aspx Remote Elect. Pump2
http://www.meziere.com/ps-1132-0-WP316R.aspx Remote Elect. Pump3
http://www.meziere.com/ps-1148-0-WP336S.aspx Remote Elect. Pump4
http://www.meziere.com/ps-1150-0-WP337S.aspx Remote Elect. Pump5
http://www.meziere.com/ps-1178-0-WP365C.aspx Remote Elect. Pump6

I'm still going to set up some tests with an electronic-digital torque meter comparing the measured tension of Delco Tensioners, old OEM styles from the junkyard, and the current Gates tensioners to see if the problems are bad specs in the tensioner-aftermarket and something got lost in re-engineering of these tensioners and they are applying too much tension to the Accessory Drive Belt System causing bearing failures of these pumps.

What an ordeal............... :hmm::bonkers:

Hope these ideas are informative.............sooner or later, we're all going to be replacing pumps every year which is why I started the "long winded thread" to document what after-market pumps are failing, if they still have the original tensioner or an after-market tensioner, and who still has the original OEM pumps/miles on it and if they have an original long style tensioner, or after-market tensioner.

I hope everyone gets where I'm going with this mystery.............or shall I say "misery"!
 

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#51 · (Edited)
"AHHH HAAA!.........Now we are getting some where"......someone or something is meu'dering these pi'mps and I the original Inspector Clouseau are going to get to the bottom of it you foo's!
http://www.trussel.com/detfic/murdera.gif

I'm really thinking the after-market tensioners are made with too much tension and "Meur'dering" these pumps! Just a theory.........
 
#60 · (Edited)
Here's Part 3 of the article on Evan's High Performance Coolant.......... Once again, sorry to divide it up. This site would not let me post a large PDF Scan.........what a P.I.T.A.

Someone please let me know if these PDF's of the Popular Hot Rodding article could be opened and read. It should be pgs. 80-83


Finally, anyone want to try this special coolant and go for 20 degrees BTDC base timing!
:burn:
 

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#62 · (Edited)
Dex-Cool is really bad stuff to use and anyone using it is playing "Coolant Russian Roulette" with 1/2 the chambers loaded!

Just do a Google on "Dex-Cool Problems, Dex-Cool gelling or sludging, Dex-Cool Class Action" that happened around 2008.

Here's some very specific problems of Dex-Cool and late model gasket failures. Our 4.9's probably don't use this type of gasket material, but Dex-Cool came out in 1996 for those model years engines that were re-designed to use that coolant, but not well enough because it created ton's of various problems!

AS SEEN IN THE FOLLOWING LINKS HERE:

http://www.zillamotorsports.com/DEX/

http://www.getahelmet.com/jeeps/maint/dexcool/

Dex-Cool has known problems with sludgeing and gelling due to any air contamination in the system. Mostly, if you have a leaky intake or bad rad. cap and introduce air into the cooling system or even a very small headgasket leak introducing air, it will make Dex-Cool turn very acidic and attack certain types of gaskets and seals, turn to sludge/gel and clog heater-cores, and rads. ect……….. GM even issued a TSB which I can post on how to flush a sludged up Dex-Cool System using the old discontinued "Preston AS100" cleaner/flush. It was a 2 sided can of 2 dry ingrediants that you can still buy at the hardware store "Oxalic Acid a.k.a. Wood Bleach" and "Arm and Hammer Washing Soda" as the neutralizer found at the grocery store. I"ve done this many times on all my cars for a good agreasive flush instead of the junk they sell at the parts stores.........some old dealerships still stock the AS100.... I've even done the Cascade Dry Dishwasher Powder flush trick also: See this link:
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1687693

The TSB procedure is posted here in blue Post #17:
http://forums.corvetteforum.com/c3-tech-performance/2395596-radiator-cleaner-flush.html

Good write up here also but back in 2003 before the "Class Action" over Dex-Cools later problems and flushing a Dex-Cool contaminated-slugged system:
http://tinyurl.com/7o59nxa


The cooling systems that use Dex-Cool also had pressurized recovery tanks to keep the air out. If anyone stays with Dex-Cool, they need to have a good rad. cap, and totally burb the system of air........AND CHECK IT OFTEN. I would question everyone who had 4.9 water pump failures to see if they were using Dex-Cool but I never used it in my systems with the failing pumps and only used Green Ethylene Glycol and like I stated before, maybe the bearing seals in these new after-market pumps are no longer compatible with Green Ethylene Glycol which is causing so many aftermarket water-pump failures.

I’m going to contact a coolant testing lab tomorrow and a few others to see what they think or if they will examine my pumps and can determine what type of seals were used.
 
#63 ·
I'm well aware of the internet Dexcool wars.

I don't buy any of the Dexcool myths (yes, MYTHS - no one has been able to build enough facts against it to prove it to be an inferior product yet - and it's been in service for over 15 years now.)

Dexcool has been employed in almost all of my vehicles since I could drive. I've yet to experience any abnormal situations from it's use. All cooling system repairs were standard and inevitable.
 
#64 · (Edited)
Dexcool Wars... Internet Myths... are you kidding me??????? First of all, do you know how hard it is to get into Federal Court to have a lawsuit filed let alone to have enough merit to be classified as a "CLASS ACTION" by a Federal Judge or State Superior Court?

Do you not believe they had highly educated expert witness and PHD's in the field of chemical engineering in order to not have the case dismissed in the preliminary evidentiary hearings so the Class Action would not be dismissed on a meritless complaint?

I'm sure the expert witness used a "Hewlett-Packard 5710-A dual-column gas chromatograph with flame analyzation detectors" on the Dex-Cool?????? I direct you to a familiar transcript and hope you are not one of the witnesses hanging outside the "Sack-O-Suds"!
http://www.law.indiana.edu/instruction/tanford/web/movies/MyCousinVinny.htm

Just to let you know, I do and have a lot of experience in the legal field and the Dex-Cool litigation was no myth which is why GM settled. Trust me, GM had to settle out BIG TIME for their lousy invention.

You probably have not experienced any problems because:
#1. You have maintained your cooling system and not allowed air to enter, or
#2. you were lucky enough to not have air enter your system.
#3, With your long term use of Dex-Cool, it obviously does not affect the 4.9 seals or gaskets and
#4. Dex-Cool has been reformulated a few times by the aftermarket to avoid patent infringement of the original forumula, but it still has those attributes of being unstable when air is introduced into the system and GM even side-stepped the language of the root of the problem in their TSB on how to flush a system that was clogged from the Dex-Cool reacting to air. Read between the lines of that TSB and why it was issued. Much of that language was not GM Engineers at work, but their legal team hard at work when writing that TSB so as not to admit any guilt with the problems Dex-Cool caused.

That's my legal take on it anyway...........

Here's a site that's not a myth: Just a small portion of the litigation of GM trying to get out of not paying claims by filing Ch.11.
http://www.dexcoolsettlement.com/
http://www.motorsliquidationdocket.com/

THE SETTLEMENT IN CALIFORNIA Superior Court:
Fact: Not Myth: $16.5 million in attorney fees
Fact: Not Myth: $1.55 million documented costs (expert witness included)
Fact: Not Myth: $140,000 divided among 80 Plaintiffs.

So Ordered by the Judge: Honorable Robert Freedman 10-23-2008
http://www.dexcoolsettlement.com/CA_finalapproval.pdf

:nyanya:
 
#65 · (Edited)
Sorry, I just don't buy it. You can tell me until you are blue in the face that Dexcool is the devil - doesn't change my opinion.

If only certain seals are affected by it, then I have to assume that there's a problem with those specific seals. Not the fluid. After all, the settlement of the class action lawsuit didn't remove Dexcool from the shelves or from new GM vehicles - the result was seal replacement for those affected. None of the resulting covered repairs required the permanent removal of Dexcool (or the discontinued use of specific formulas) from the vehicle because the lawsuit provided NO facts proving that Dex was the actual source of any problems. Only sub-par seals were blamed, and again - ONLY on certain engines of certain years - not ALL engines equipped with Dex were affected.

The links you posted are interesting, but conflicts over coverage really don't say anything for the bottom line here. They say nothing about Dexcool itself.

The fact that, in your last post, you can assume that 4.X's might be able to handle it says a lot - these engines were retired before Dex was even introduced, yet it appears to have no effect on them. If the problem was Dex, wouldn't it be an even greater threat to all engines and gaskets designed and produced before Dex's introduction?

No air in the cooling system? There's plenty in my overflow bottle which, as long as the level in the rad doesn't lower significantly due to leaks, doesn't even experience any circulation. If Dex + air in the system was a problem, the Dex in my overflow bottle had plenty of time to gel up and eat away the plastic. Yet, it has never done so.

FWIW, I've owned and used Dex in more GM engines than just the 4.X... I've also used in in a number of engines from the 60 degree V6 family with no abnormal results. That family of engines was one of the supposed affected.

And yes, I've replaced many a intake, head, and water pumps gaskets in GM vehicles equipped with conventional green coolant. Those repairs would have been necessary whether the system was filled with Dex or not.

To make myself clear, I don't find the lawsuit itself to be an internet myth - recognize that it occured - I find the continued blame of Dexcool to be the myth as it has still never been proven.
 
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