Well, I decided that instead of gambling $100 on whether or not GM would replace my leaking radiator that I would just go out in search of another one. I talked to a company about building me an all aluminum one but they never got back to me.

I found this place online called Outlaw radiator (Auto Radiator and Truck Radiator at Radiator Discount Prices.). They offer a radiator for the H3 that matches factory specs but an UNLIMITED LIFETIME warranty. Gotta like that! Their price was $227 plus tax with free shipping. Now I thought that was a good price, but they said on their site that if you see a comparable radiator online for the same price they will match it.

So I saw that Genesis Auto Parts listed an H3 radiator for $140 (2007 Hummer H3 RADIATOR RAD22295X9589A 3.7L L5 228 | Radiator | Hummer Auto Parts). Several other places online do as well. Theirs has a LIMITED LIFETIME warranty. So the guy said he thought he could match it but would have to get approval. He came back within one minute and said my final price with tax was $151.55 and I will have it at my house tomorrow morning! Much better than having to deal with GM!

Hope this might helps some of you other guys that are having the same problem. Now I wish I could find an electric fan system to install while I have it apart!

 

Electric Fan Kit PCMforless.com

 

Cool! Thanks! Now if I just had the money to get an electric fan kit! haha

 

Oops. I posted the part about my radiator fix today but then I realized that I had forgotten to mention in this thread that the mail order radiator was not right. It was the right radiator in shape but it has screw in trans line fittings instead of push in. So back it went and they I went for the fix as shown below...

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Okay, the radiator saga is finally over for me. And I learned something too...

When the aftermarket radiator wouldn't work, I went on a search to have my factory one rebuilt. Went to a family owned place here in town that has been around for years. I told the guy the entire saga... And about how so many people on the forum are having the same issue. Without knowing the miles on my H3, he said that Hummers usually start to have radiator problems around 80k. That is right where I am.

I also told him that it seems that a lot of people are having problems with the trans cooler breaking and getting water into their transmission. He said that was because of the electrolysis caused by the DexCool. Do a Google search on 'DexCool electrolysis' and read about all the problems and the law suits. Then he showed me the bottom tank of a factory radiator with the stock trans cooler, and then an aftermarket one. The stock trans cooler is about 1.5 inches thick. The aftermarket one (1-800-RADIATORS) was only .5 inch thick. So he checked mine out while he had it apart and said that my trans cooler had no damage. Along with the new DexCool, he put in an additive to stop the electrolysis and protect the metal.

All in all, my rebuilt radiator with new tanks, new fluids, all cleaned up and flushed, new 0-rings on the trans lines, and a new cap just for good measure cost me $260. I just dropped it off and they gave me a ride home. I came back 4 hours later and it was done. What a bargain! Just not worth hassling with GM with it in my opinion. And even with GM, at this point you are not sure if you are getting a new GM radiator or an aftermarket.

 

No. It was a red bottle. I'll call him today and find out.

 

Tom,
The product used is from a company called Kool-It. They make several products all related to radiators and cooling. This particular one is called Supreme Coolant Treatment and is specifically for protecting your parts from electrolysis. Also says it reduces temps by 5-6 degrees. I never had any overheating issues anyway though. The guy says you can get it at CarQuest but I bet it is available other places as well. There is a link to find retailers on their web site. Looks like cheap protection to me especially since we know people have been having issues.

Kool-It Supreme Coolant Treatment

 

Some info on my radiator situation... I bought my H3 with 75k on it. 2 days later the radiator starts to leak. It was rubbing near the top somewhere. I.has the dealership replace it with a new OEM unit. They wanted over $800! I ralked them.down to $560. All has been well now for 2 weeks.

 

I suggest that anyone, even if you have a new radiator, put the additive in there. Visiting that radiator shop was a real eye opener for me.

 

What all has to be disconnected to remove and replace it? How does the transmission cooler tie into this equation as others have mentioned? I am going to have to replace mine this week and would consider myself to have moderate wrench turning abilities. I know im a new member here, but any help would be greatly appreciated. Thanks!

 

I changed my radiator out at 75K miles this weekend. This is obviously a design flaw. There is lack of clearance between the top tank and core support. Here is a picture of the groove that was worn into the tank by the core support and another showing the resulting cracks.

I intend to pursue reimbursement from GM on this. They need to own this problem.

I will post a step-by-step soon on how to do the radiator swap out.