Trans cooler bursts!
 

I own a 2005 H2 - with 58,000 miles
Here's the deal: Engine running great. I feel a slip in the trans shifting from 2nd to 3rd. Then notice antifreeze pouring out the overflow. I shut down the truck and had it towed to the dealer. The diagnosis is: The trans cooler bursted in the radiator mixing the antifreeze into the trans and blowing the trans. They say the entire cooling system needs to be changed, rad, hoses, clamps, heater core, etc. and then the trans plus the trans cooling system. cost $7600 AAGH!

The H2 is out of warranty. I called corporate and they are investigating the issue. The truck has never been in the dealer for any repairs. All maintenence has been done by me. Oil changes, greasing (the basics).
Corporate has been investigating for 1 week now because they claim that if the truck was taken to the dealer for maintainence this may have been avoided. I think this is bull**** and sounds like a part failure to me.

The truck has some mods: Intake, borla cat-back exhaust, shift kit and diablo programmer.

Wondering if anyone else has had a similiar situation. Also any feedback is appreciated.

Re: Trans cooler bursts!
 

Shift Kit?....investigation will probably end there!


Like it or not, this is most likely true!

Doesn't sound like you had ANY of the Required Maintainence Done!...Like the Transmission! :violin:

Re: Trans cooler bursts!
 

Humgood- I would flush everything real ,real, real good and give it a try . You have nothing to lose if the tranny slips rebuild it. I would even use the old radiator again. Just use a external tranny cooler this time. Obviously this is a cheap fix and what i would do. But where your rig is so new you might want to do all new parts. Sorry about your problem , and good luck. doug

Re: Trans cooler bursts!
 

Hey dont like the sound of that ,what can you do to avoid this , i would rather spend 500 bucks now than a few thousand later , nasty

Re: Trans cooler bursts!
 

Thanks guys for all your attention.

Just got off the phone with the GM at the dealer that did the diagnosis.
He says he got me $4000 from Hummer corp. And now he will be able to bring my side down considerable. It seems like the GM was at bat for me. He has a radiator on the floor which will give me for have price. All hoses must be replaced because the trans fluid will eat the rubber. As for the core, flushing is sufficient. He suggested a brandie new transmission. The trans would have to be torn down completely and then rebuild, he says the difference would be about $1000 for the new one. And the new trans comes with a 3 years 100,000 mile waranty - that right there is worth the $1000 bucks.
So I have chose to stick with him and have the dealer do the repair. Seems as though it will cost me out of pocket tops $2000.

$2000 - New radiator with trans cooler, all new hoses, brand new trans with warranty. Flushing the systems with all new fluids. Seems reasonable to me.

On my own I will disconnect the internal trans cooler and run a larger external cooler:


What cooler did u use?

Re: Trans cooler bursts!
 

Yes if you have some details on this and any photos i will do the same :mad:

Re: Trans cooler bursts!
 

Thanks for the info.; I will be adding a external cooler as soon as it is returned.

No doubt on the $$$ thing. Plus a tranny with a 3 yr 100,000 mile warranty. I'll take that.

I also have spoke with many, and a tech from a delaer says keep an eye out for a recall....if one pops up, I can get re-embursed for the entire job - being it is recorded and repaired by the dealer.

Good thing I kept my cool and let this roll it's own way. :jump:

I'll post all info and some pics up when I do the trans cooler externally, for all that need it. I am home for the holidays so more than likely have this completed before the 1st of the New Year.

Re: Trans cooler bursts!
 

Thanks for the heads up on the tranny cooler and the potentual problem!! Just ordered a coolmax cooler #47391 from Bulkpart.com $115.00 shipped. will do this mod asap as I live in FL. My new to me 03 has 45.000 on her now and just starting to pull it all togeather for some trail time.

Thanks again for the Great Info.:grouphug:

Be Safe

Re: Trans cooler bursts!
 

HI ROADCAPT

Could you please take some photos of your cooler make dimensions etc , being over here in Czech Republic i need to so some pics and measurements so i can order one up

thanx

Re: Trans cooler bursts!
 

Hi Guys just so i know i am ordering the right one its this one yes ?

Tru-Cool MAX transmission cooler *WITHOUT external thermal bypass

Code: 4739-1








Tru-Cool # LPD47391 40,000 GVW rating, 45,000 BTU rating
8 1/2 x 22 3/4 x 1 1/4 inch
3/8 inverter flare (fittings are included for thread to hose barbs)
WITHOUT external thermal bypass. Lower cost for locations where there are mild winters!
the thing is i have bad winters and hot summers as well will this matter

Re: Trans cooler bursts!
 

Had the same problem...Thank God for extended warranty...it covered it all...rebuilt transmission, rental car for 2 weeks, and my dealer even paided my deductable...only one problem...the extended warranty would not pay to replace the overflow bottle, so even after flushing it 3 times, there is still transmission fuild in the rad....the honeycomb core of the overflow bottle doesn't allow for a total system flush.....make sure they replace yours!....good luck!....i will be putting an ext. cooler on first chance i get!

Re: Trans cooler bursts!
 

Thanks for the heads up on the overflow bottle.

This seems to be a very common problem......i would think a recall is in order here!

Re: Trans cooler bursts!
 

AK47 Yes that is the right part Number however you will need the trans bypass system in you area. It allows cold fluid to bypass the cooler till it warms up. Need the bypass at below 32F. I have a write up on the install over on the H2 forum.

Be Safe

Re: Trans cooler bursts!
 

I would have them replace the water pump gaskets while they are in there. Have seen them fail shortly after due to the atf eating them away.

Re: Trans cooler bursts!
 

Thanks for the info.....I spoke with them. They said they would not do it unless I paid for it.....So I had them note my concern on the invoice, the GM said if it breaks through it will be noted and covered.


I picked up the truck today. Total invoice was $8300. Hummer picked up $5200. The balance was $3100. The dealer discounted me down to $2100.

Re: Trans cooler bursts!
 

Yes, i am not one for letters.....but I will be writing one to hummer and one to the dealer for their excellent service. They even returned ALL my calls with in one hour......AMAZING!

Re: Trans cooler bursts!
 

I finally got time to post -

I looped the tranny section of the radiator with a hose, closing it and elimanating the possible of the pepto bismal effect ever happening again.

With the information provided by Phil D (Thanks you the man) I purchased the larger of the 2 cooler Tru cooler #4739-1. I easily mounted it slightly off center towards the passenger side of the rig leaving the power steeering cooler in it's place.

The tranny now runs consistently at 150 degrees and the chance of the trans fluid mixing with the antifreeze is eliminated.

Thanks guys for all the awesome info.:jump:

Attachment 39259
brand new silver tru cooler 4739-1



Attachment 39260
Black hose is link to close off radiator section
Orange hose is feed to the new cooler

Re: Trans cooler bursts!
 

I have been giving this some thought and like your idea. It appears though I may have to think of something different as it appears there is no room in front for supercharger cooler. It is hard to tell but, I think I would not be able to do this unless i moved SC cooler and added a fan to it so it does not have to have forced air from dual electric fans.

HUM GOOD have You seen the Magnuson SC cooler? Can You tell what would need to be done with this MOD to work with SC?
Thanks

As usual Phil is the man with the plan. Thanks Phil!!

TAZ

Re: Trans cooler bursts!
 

shoot me a pic of it with measurements.....I'll measure it up with the tru cool and see if they can be mounted together.

Re: Trans cooler bursts!
 

Open up the fake top hood vent on the H2 like the H1. Place your coolers there.

Custom hood grill - http://www.amazon.com/dp/B000KOSRHE?tag=ebuyitonline&camp=14573&creative=32 7641&linkCode=as1&creativeASIN=B000KOSRHE&adid=003 5N7BDX4R46K012N40&

Re: Trans cooler bursts!
 

I run a functional cowl hood scoop over the hole we cut where fake vents use to be.

It would have quite a bit of header heat as well as radiator etc. heat going out the scoop. There are many places to add different sizes of coolers even if you need to add a fan if you do not get normal air flow.

TAZ

Re: Trans cooler bursts!
 

from the picture it looks you also remove the small trans cooler and brackets to mount the 4739-1 . and use some the mounting holes of the old trans cooler to mount the 4739 .and than you need to plug all 4 lines to the rad. :confused:

Re: Trans cooler bursts!
 

Yes replace the smaller cooler with the 4739. I used one hole(top drivers side) from the old cooler. Drilled one new top pass. side. The bottom 2 used brackets that come with the 4739.
As for the radiator. I just by-passed completely. There are 2 lines (one in and one out) they are looped by just clipping the exsisting tubing and looping a short pc of the tubing which comes with the 4739. The 2 lines which came from the rad go to either end of the new cooler(cooler is not directional) this completes the 4739 loop and we are good to go. Very simple.
I found that keeping the connectors in place and clipping the tubing, the supplied rubber hose slid over the exsisting tubing as a perfect fit..

Re: Trans cooler bursts!
 

what about the 2 lines on the drivers side of the rad ? my rad has 4 lines 2 on each side that go into the plastic tanks on ether side of the rad .

Re: Trans cooler bursts!
 

I looked all of this over today and I would not just loop the oil cooler lines on the drivers side. There is so much room over there that you might jut as well add a small cooler, or clean out your factory tranny cooler and mount it over there.

On another note- how many of these trans coolers are bursting, and are they bursting on the 03-04? or newwer? We added a second tranny cooler and a fan on a 1500hd this weekend... the second cooler was unnecisary, but the small 8" fan rocks..... Set up on a thermostat....

Re: Trans cooler bursts!
 

going to leave the oil cooler as is for the time being.

Re: Trans cooler bursts!
 

The issue is not in the trans cooler itself. It is in the side resi of the rad where the lines pass through. These are located on the passengeer side of the rig. The larger tubes are located on the drivers side, which go to the engine block....thinking some kind of oil cooler. I didn't touch them.....trying to investigate if anyone had any issues with this bursting, causing oil to mix with antifreeze......that would suck! If no issues I plan on leaving it alone.

Re: Trans cooler bursts!
 

Thats what I want to know!

Re: Trans cooler bursts!
 

mine just did.

~14k miles

GM would not participate in any repairs, under any circumstances.

talked my way up to John Martin (regional guy for alabama and mississippi)
678.787.7200

~$2000 for a new radiator, external tranny cooler, and some other work.

pulling out the stops for a 4L80E - I'd rather blow a diff than another trans.

Re: Trans cooler bursts!
 

But you are supercharged with a modified tranny...... How many burst stock...:(

Re: Trans cooler bursts!
 

Just ordered the tru-cool, as my factory warranty is just expiring- looking forward to this install , ill let u know how it goes, thanks for the info:D

Re: Trans cooler bursts!
 

Your welcome......
I have put about 10,000 miles on it since the install. The trans is running great and the temp (with about 5500 lbs behind me) has only gone up to 165 highest and that is at about 3500 rpm uphill - as soon as I level off (rpm to 2500) the temp comes right back down. The average outside temp at that time was between 90 and 95 and humid......

i'M hApPY ......hEe.....HeE.......hEE!!!!!!!

Re: Trans cooler bursts!
 

I know this is old But I have a 1 question

My trans cooler burst on me this week I am going to install external trans cooler. If I flush everything real good will I still need to replace the radiator if I hook up the bypass?

I cought this early enough that I think I saved the trans but I will find out from the transmission shop soon . Sounds like I have a 50 /50 chance the warrenty company will cover all of this mess. lets hope for the best.

:raar: