# Transmission Cooler Line Leaking



## Robby (Mar 1, 2013)

Very few vehicles made don't seep slightly from the cooler line hose to metal junction......those of us in the North (you, me) will see it more often in cold temperatures.

The aluminum tubes shrink slightly at the barb joint and because it is cold, trans pressure is elevated.....a cold seep is the result.

You can replace the lines, but the seep will return in about two seasons.

Degrease it and see how severe the seepage is.....you might be looking at two years of accumulation.

Rob


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## spacedout (Dec 7, 2010)

Robby said:


> Degrease it and see how severe the seepage is.....you might be looking at two years of accumulation.


I cleaned mine off this spring and found very little leakage when warm outside. Instead of paying all that money for the line replacement it made way more sense to just have the transmission fluid changed to ensure its still full. Looking again this fall I see new fluid seepage and its possibly getting worse, so I may end up replacing it at some point. 

As close as those lines are to the hot exhaust/turbo and as many cars do leak I wouldn't be surprised if there is a recall due to a fire risk.


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## Aussie (Sep 16, 2012)

I had my Holden Cruze diesel serviced by an independent workshop 2 days before the warranty was up and they found some green fluid on the engine. They said it looked like transmission fluid. I took it back to the Holden dealer and it was a seal between the transmission and engine. It took a day and half to fix and no charge. Two days later I got a recall for the surge tank, I never had a problem with it, but they changed it anyway. I have a 6T45 transmission in my diesel.


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## cruze2011white (Feb 2, 2011)

I had to change mine this past spring. If its not leaking bad you can wait. Its not hard to do just takes some time and you will need a tool to release the quick connect pin. Just make sure you can get the car high enough off the ground.


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## KENSTV123 (Sep 21, 2014)

Using a Viton o-ring might help as well as using a o-ring with the next size up cross section diameter--that is if it can be forced in, this flattens the o-ring allowing for more sealing surface area


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## Robby (Mar 1, 2013)

The lines leak at the hose to tube interface, known as a 'barb', not where the tubes meet the trans or cooler at the radiator.....there are 'O' rings at those points but very rarely leak unless mishandled at some point.

The crimp at the barb is not serviceable and there are no 'O' rings at that point.

Rob


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## boraz (Aug 29, 2013)

Robby said:


> Very few vehicles made don't seep slightly from the cooler line hose to metal junction......those of us in the North (you, me) will see it more often in cold temperatures.
> 
> The aluminum tubes shrink slightly at the barb joint and because it is cold, trans pressure is elevated.....a cold seep is the result.
> 
> ...


eggsactly, those aluminum connectors are pita, just cut em off and use a repair kit


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## diesel (Jun 8, 2013)

Hmm, I suppose I should check this on mine. I've never seen any transmission fluid on the ground, though. 145K miles.


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## MilTownSHO (Oct 9, 2013)

diesel said:


> Hmm, I suppose I should check this on mine. I've never seen any transmission fluid on the ground, though. 145K miles.


I have not either just noticed it while the car was up in the air getting the winter tires put on.

Thought I should get it taken care of while still under power train warranty...guess not.

Honestly I'm not worried about it.


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## jsusanka (Jan 31, 2011)

not to bring back an old post but I started my spring cleaning of my engine bay and noticed my transmission cooling lines looked wet like seeping or sweating. Nothing on the ground and the car runs and shifts fine. 

So I guess I have the dreaded transmission cooling line leak where the rubber meets the metal tube interface. That looks like exactly where it is coming from because that is the dirtiest part. 
They were always dirty every year and I thought it was just sweating along with road grime. I always just cleaned them and went with my business. 

I have been reading on other GM forums like truck forums etc that is pretty common with GM vehicles. 
Is there a permanent fix for this because I don't want to be giving money to a problem that is going to happen again. 
From the forums it looks like it has been an issue with GM cars and trucks for while so I guess GM doesn't feel the same. 
I was thinking of doing something like this and put this around where the rubber and metal tube meet. 

LeakSeal® Self-Fusing Tape

If getting it fixed at the dealer isn't going to permanently fix the problem I would rather just buy that product and do my best to fix it that way. 

Is there a TSB on this issue?

Here is how one guy fixed it on his truck. 

https://www.youtube.com/watch?v=PQSw8JrQ9U0

One side note don't wipe them off when the car is hot cause the lines are pretty close to the turbo and well that turbo tends to get hot. Wonder if this was the cause of some the fires that cause the shield hack.

So looking at the parts here:

https://www.gmpartsdepartment.com/p...iteid=214533&vehicleid=313733&diagram=CC11087

The price on the parts don't look to bad even if you replace both the inlet and outlet tube. 
I see the connections on top of the transmission for the inlet and outlet tubes but not sure about the connections at the bypass valve. Are those connections hard to undo and what is involved? 
Doesn't really seem like it should cost too much to have both the inlet and outlet tubes replaced.


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## pontiacgt (Jan 12, 2011)

I think they are the same on all cars. I think its a common leak spot for any car after awhile. Its also possible the manufacture of the parts didn't do a good job with these.

The engine fires were more than likely from sloppy oil changes and not from these leaking. Can't prove it but even people who had the oil turbo line leaking didn't have fires.


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## diesel (Jun 8, 2013)

I've decided to do no repairs on mine at this time and just keep an eye on it.


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## KpaxFAQ (Sep 1, 2013)

I'm kinda up in the air on mine too. I may just pop the level plug and top off next oil change and see how much I lost. It will be easy since I made a little access hole directly under the plug so I don't need to drop out that whole panel.


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## jsusanka (Jan 31, 2011)

Anybody know what the purpose of the hole is on the crimp where the tubing and rubber hose meet?

I am guessing it is an artifact from the manufacturing process like that is where the machine lines up the hose with the metal tubing.


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## KpaxFAQ (Sep 1, 2013)

To leak transmission fluid?


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## jsusanka (Jan 31, 2011)

KpaxFAQ said:


> To leak transmission fluid?


LOL everyone is a wise guy. :signlol:


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## jsusanka (Jan 31, 2011)

Well took my car to the dealer and they verified the crimps were seeping on the rubber lines of the transmission cooling lines. I just decided to have them replace them and hope it doesn't come back.. 250 for both lines installed out the door. 

What is weird is that I brought some of my amsoil transmission fluid with me so they could top it off because I had the fluid changed at the dealer where I bought the car at around 35,000 or 20,000 miles ago with Amsoil. 

Well replacing the lines they did not use any of my fluid as they said it was overfilled and they did not need to add any. I just found that out today since I called them back after looking at my fluid in the trunk. Could this possibly make it shift smoother and cleaner. I shift my man-umatic manually most of the time because I do a lot of city driving. I notice now after I turn the car off like to get gas or something and then start to go the 3 to 4 shift manually always had a little bump or thud to it but now that is gone (never thought too much about it just thought that is was normal or a characteristic). Could too much fluid cause that? I also wonder if overfilling could cause the crimps to seep on the cooling lines?


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## diesel (Jun 8, 2013)

jsusanka said:


> Well took my car to the dealer and they verified the crimps were seeping on the rubber lines of the transmission cooling lines. I just decided to have them replace them and hope it doesn't come back.. 250 for both lines installed out the door.
> 
> What is weird is that I brought some of my amsoil transmission fluid with me so they could top it off because I had the fluid changed at the dealer where I bought the car at around 35,000 or 20,000 miles ago with Amsoil.
> 
> Well replacing the lines they did not use any of my fluid as they said it was overfilled and they did not need to add any. I just found that out today since I called them back after looking at my fluid in the trunk. Could this possibly make it shift smoother and cleaner. I shift my man-umatic manually most of the time because I do a lot of city driving. I notice now after I turn the car off like to get gas or something and then start to go the 3 to 4 shift manually always had a little bump or thud to it but now that is gone (never thought too much about it just thought that is was normal or a characteristic). Could too much fluid cause that? I also wonder if overfilling could cause the crimps to seep on the cooling lines?


I would think that overfilling would cause higher internal pressers which could cause harsher shifts. I think the lines will seep regardless. "They all do that"


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## NHRA (Oct 12, 2014)

jsusanka said:


> Well took my car to the dealer and they verified the crimps were seeping on the rubber lines of the transmission cooling lines. I just decided to have them replace them and hope it doesn't come back.. 250 for both lines installed out the door.
> 
> What is weird is that I brought some of my amsoil transmission fluid with me so they could top it off because I had the fluid changed at the dealer where I bought the car at around 35,000 or 20,000 miles ago with Amsoil.
> 
> Well replacing the lines they did not use any of my fluid as they said it was overfilled and they did not need to add any. I just found that out today since I called them back after looking at my fluid in the trunk. Could this possibly make it shift smoother and cleaner. I shift my man-umatic manually most of the time because I do a lot of city driving. I notice now after I turn the car off like to get gas or something and then start to go the 3 to 4 shift manually always had a little bump or thud to it but now that is gone (never thought too much about it just thought that is was normal or a characteristic). Could too much fluid cause that? I also wonder if overfilling could cause the crimps to seep on the cooling lines?


$250 is half of what my dealer wanted to charge me when mine were leaking. I would be concerned that your dealer did not check the fluid level properly if they said it was overfilled. I would check back with them and have them describe the process in how they determined this. 1/2 half quart minimum needs to be added after draining from the small plug is pulled to let out any excess fluid. They would of had to remove the small plug and release any fluid untill it stops draining (after it reaches full operating temp) then add 1/2 half a quart.


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## jsusanka (Jan 31, 2011)

Yeah too bad we can't trust the own manufacturer's dealers to properly service a car. I have seen a few videos on how to check and fill it I figured they had some secret dealer manufacturer way of checking it without having to waste fluid.

I had the transmission fluid changed and flushed at around 35,000 miles at the dealer where I bought the car and they were glad to use my Amsoil transmission fluid I brought with me. I have never touched it so I guess they overfilled it if that is possible. It does seem to shift a little better and like I said when I stop the car for a little bit and restart and go while they car is warm the 3 to 4 clunk is gone when I am shifting manually. I chose a different dealer this time because they had a shuttle to my work and it is closer to my work. 

I will probably get the fluid the changed around the 60,000 mile mark again since I have some more Amsoil transmission fluid I bought with a gift card I had from xmas. I am currently at 55,000 miles. I just have to get a few more quarts. 

I may go somewhere different to have it done other than a GM dealer. I don't know.


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