# Radiator or cooler line issue?



## Fightingmarmot (Dec 29, 2016)

Hello!

Sorry about the response, I have no idea what happened so I will try to be detailed. Thank you for the help in advance!

2012 cruze 2LT 84k miles. 6t40 auto transmission.

Recently my lower transmission cooler line started leaking at the crimp. They are the lines that are towards the front of the car that run from the radiator to I think the transmission. I disconnected the lower line that runs to the bottom of the radiator (looking at the car into the engine it is on the right side of the radiator, had to take tire off to disconnect it. They are twisted kind of weird at one point before they run down to the radiator). When I disconnected it all my coolant drained out of the radiator until my reservoir was empty. I pulled the line up and it was indeed my leaking cooler line. I put the line down and what I think was ATF ran out and caused my drain pan to turn into like a soup. I fixed the line and reconnected it then filled my coolant again. 1k miles later there is no automatic in the coolant and the transmission shifts fine. Why did coolant come out? There's no leak that I can see? Only other issue I've had was the burning oil smell and a new valve cover and oil cap fixed that. I drained/filled my transmission and it was pure automatic.

Are those lines actually transmission cooler lines? If you open the hood and look down they are in the front of the engine. I'm pretty concerned.

Thanks again!


----------



## carbon02 (Feb 25, 2011)

Ok-

Here's a link to a diagram so that everyone can ground themselves in what was connected and disconnected. 

http://www.wholesalegmpartsonline.com/images/parts/gm/fullsize/1109281P04-021.JPG

Part 15 is solid aluminum. I have removed part 15 from the top connection at the radiator and I didn't get any leaking coolant. I would never remove it again. I was trying to flush the tranny fluid completely for a complete change. Worked well but there is no flexibility of line 15 and it was a bear to line up and get back together. I actually had to unthread part 4 the quick connect nut. Place this on the top part of 15 and install back on the radiator cooler. 

If I'm understanding correctly the OP removed and replaced part #7 which is the fluid out of the transmission into the cooler assembly. Where things get crazy is at part 19. I believe part 19 is a thermostatic valve. When it's warm enough it diverts fluid into the cooler part #2. When the fluid is cool the valve remains closed and the flow goes through the radiator cooler side tank like a traditional car. 

I suspect the transission radiator cooler must be a vessel that is inside the radiator tank. I wouldn't think this would be able to move around when line connection nut #4 at the bottom of the side tank is removed. 

OP are you saying you got coolant out of that connection when you removed the transmission line? Very odd that would happen. We don't know how the side tank of the radiator is constructed, but I would hope the tramsission cooler would be built into the tank, and not allowed to move around.


----------



## carbon02 (Feb 25, 2011)

The post below is for the Cooler Pipe Connector the nut at the bottom connection that holds the bottom transmission fluid outlet to cooler inlet line. They have you draining the radiator to do this? Maybe the fluids can mix? So I got lucky by removing the top connection?? I don't know. Don't remove both connections or the transmission oil cooler will fall into the radiator tank assembly? See below.. 

This info is from Chiltons Online so I tend to trust the source. 

To remove the line, they have you draining the coolant, removing the radiator hose, and the Turbo intercooler hose for access. Along with the battery and battery tray. Maybe all this is needed? It's very tight working in that area, and while some have claimed they have removed and replaced their transmission cooler lines, there have been no how to's written on this. I thought removal of the air charge tubes actually required removal of the front bumper for access at the bottom connection. Yikes, seems like a mess, and I have a weeping line, that weeps only while cold. 

Is draining the radiator critical for just space constraints, or is it done for some other reason like the oil cooler that is inside the radiator tank assembly?

Anyone else with shop experience that can comment on this one? Seems like a lot of work for a cooler line. 

Transmission Fluid Cooler Pipe Connector Replacement - Radiator (LUJ)
Transmission Fluid Cooler Pipe Connector Replacement - Radiator (LUJ)

Removal Procedure

Remove charge air cooler outlet air hose. Refer to Charge Air Cooler Outlet Air Hose Replacement (Manual Transmission) | Charge Air Cooler Outlet Air Hose Replacement (Automatic Transmission).

Drain the cooling system. Refer to Cooling System Draining and Filling (GE-47716 Fill) | Cooling System Draining and Filling (Static Fill).


Click to Enlarge
Remove the fluid level drain plug (1).

Drain transmission fluid into a suitable container.

Remove the transmission oil cooler pipes from the oil cooler fittings on the radiator. Refer to Transmission Fluid Cooler Hose/Pipe Quick-Connect Fitting Disconnection and Connection.


Click to Enlarge
NOTE
Note

Do not remove the upper and lower transmission oil cooler fittings from the radiator at the same time other wise the transmission oil cooler will fall inside the radiator end tank.

Remove the oil cooler fitting (1) and the O-ring (2) from the radiator.

Installation Procedure


Click to Enlarge
Inspect the NEW O-ring (2) seals for cracks, cuts or damage. Replace if necessary.

CAUTION
Caution

Refer to Component Fastener Tightening Caution.

NOTE
Note

The correct thread engagement is critical. Cross-threaded fittings can achieve proper tightness and still leak.

Install the oil cooler fitting (1) to the radiator and tighten to 20 N·m (15 lb ft).

Install the transmission oil cooler hoses to the oil cooler fittings to the radiator. Refer to Transmission Fluid Cooler Hose/Pipe Quick-Connect Fitting Disconnection and Connection.

Fill the cooling system. Refer to Cooling System Draining and Filling (GE-47716 Fill) | Cooling System Draining and Filling (Static Fill).


Click to Enlarge
CAUTION
Caution

Refer to Fastener Caution.

Install the fluid level drain plug (1) and tighten to 12 N·m (106 lb in).

Top up transmission fluid and check transmission fluid level. Refer to Transmission Fluid Drain and Fill.

Install charge air cooler outlet air hose. Refer to Charge Air Cooler Outlet Air Hose Replacement (Manual Transmission) | Charge Air Cooler Outlet Air Hose Replacement (Automatic Transmission).

Inspect for fluid leaks.

Not sure how to read the labor times below, but 1.4hrs warranty to 1.9 hours general, is that per line? Those are regular hours not severe. 


System: AUTOMATIC TRANSAXLE
Subsystem: SERVICE TRANSAXLE INSTALLED
Operation: Oil Cooler Lines, Replace
Time Category: RegularSevere

Description: OEM/Dealer (hrs):Regular (hrs):
Hose/pipe assy. 1.4 1.9
Inlet or outlet 0.7 1.0
Notes:
Regular (hrs) - Chilton suggested service times based on normal operating conditions
Severe (hrs) - Chilton suggested service times based on severe operating conditions
OEM/Dealer (hrs) - OEM warranty times


----------



## carbon02 (Feb 25, 2011)

Original Poster (OP)

How much stuff did you have to disconnect to get at the lower hose? You mentioned you pulled the wheel. How did you gain access to the connection, from the bottom, or did you remove part of the wheel liner?


----------



## Fightingmarmot (Dec 29, 2016)

Thank you for the reply! Yes it was part number 7. When I removed the line from the radiator my coolant ran out. I had to unbolt something to get it out


----------



## Fightingmarmot (Dec 29, 2016)

I removed a couple shields and I jacked the car up and couldn't reach so I took the tire off. From there there was a plastic tube of some kind (looked throttle related) had to be unclipped and moved aside


----------



## Fightingmarmot (Dec 29, 2016)

Just rechecked everything and it's fine. I guess that is how it is. I was just concerned that coolant came out instead of automatic. Thank you for the help


----------



## carbon02 (Feb 25, 2011)

Fightingmarmot-

I need some help, as my bottom transmission line is leaking. Did you remove the radiator hose, or the throttle air pipe connection inorder to reach the connection of the bottom coolant line? 

The plastic air pipe connection at the top looks easy to loosen and remove, but the bottom looks like it could be a mess I'd rather not get into. 

Did you unthread the connector from the bottom of the radiator, or did you just remove the clip on the transmission fluid line? 

It's 5F where I'm at in the middle of winter. Trying to figure out if I can tackle this in the garage, or if if this going to be something that has to be taken in. 

The line that is leaking at the crimps is the line that attaches to the top of the transmission. No battery removal required?

So you did or didn't have coolant drain from the bottom transmission line connection? 

Thanks-

Carbon02


----------



## Robby (Mar 1, 2013)

To the readers......these cooler lines are covered under 5yr 100k powertrain so take a minute to determine if you are repairing something on your dime that is not your responsibility.

Rob


----------



## carbon02 (Feb 25, 2011)

5 year powertrain is over for me. It ended in September 2016, as mine was a 2011 build. I may have been able to show a leak before then, but it would have been subjective. Now it's clearly the line that runs from the top of the transmission to the bottom of the radiator. 

The connection that's going to be difficult is the bottom to the radiator. Book says drain the coolant and remove radiator hose, and also remove air charge hose. 

While removing the top of the air charge hose is easy, the bottom requires bumper cover removal to find the clip. I'm hoping I can access the transmission clip from the bottom? Yet it appears that the engine frame member is right in the way, so maybe top down is easier than from under side. 

Any tricks would be appreciated. It's really cold in the Midwest, not sure I'm equipped for a long battle. Yet it's more than a slight weeping. Not a continuous drip either. I'm considering options.

Thoughts are welcome.. 

Thanks- 

Carbon02


----------



## Fightingmarmot (Dec 29, 2016)

Hello!

It was plastic. If you go under you will see it clipped on with a weird clip that you have to pull apart to remove. I didn't touch the radiator hoses which is why I got scared when coolant came out. The plastic part is very hard to move out of the way. I finally managed to push it down with a lot of force but I didn't realize that it had some flexibility to it. 

Thanks 

Also I don't trust dealers. Took my 06 impala in for a recall and they "mixed my car up with another impala" and drained my oil. They refilled it and didn't tighten the drain bolt so I developed an engine knock. My dad was a gm mechanic so I learned a lot growing up. Smart to do it myself? Probably not. Fun? Yes.


----------



## Fightingmarmot (Dec 29, 2016)

Oh sorry, I didn't remove my battery, but if you're not gonna go under then it may have to be. Those crimps go bad all the time. Every GM vehicle I've owned had them go bad at some point except my impala.


----------



## Fightingmarmot (Dec 29, 2016)

I did not take the bumper off either... I jacked it up and took the tire off. It's tight and I cut my hand but it can be done.


----------



## carbon02 (Feb 25, 2011)

Thanks for the replies, the site didn't notify me of your responses earlier. I have a hose ordered off amazon, but I haven't figured out if/how I'm going to do this. It's currently 5F for a high, and the car is sitting.

Pulling the battery is not hard, if it gives you access to the lower radiator fitting. 

I'm assuming you used a pick to remove the clip to get the line free vs. removing the fitting all together from the radiator, and then removing the connector from the old line.

I can see how you may have done it I think. It's very tight, and will take lot's of patience. Which is ok if the garage is warm! 

Thanks!


----------



## Fightingmarmot (Dec 29, 2016)

Hello!


It took me a while, but I spent a long time trying to figure out how to push that intake pipe thing out of the way. The clip was pretty easy to remove, but to bring both hands in to pull it is a little tight. I think when you see where it's connected you'll be fine lol. I know I am making it sound confusing but honestly it wasn't that bad. 90% of the time I was freaking out about coolant coming out xD


----------



## OldWhiteChevy (Mar 5, 2013)

Sorry to bring an old thread back to life, but my warranty info seems to say otherwise: "Exclusions: Exclusions from the powertrain coverage include cooling lines, hoses, radiator, sensors, wiring, and electrical connectors." Is there a special "secret" warranty on this problem?


----------



## Rivergoer (Mar 30, 2017)

OldWhiteChevy said:


> Sorry to bring an old thread back to life, but my warranty info seems to say otherwise: "Exclusions: Exclusions from the powertrain coverage include cooling lines, hoses, radiator, sensors, wiring, and electrical connectors." Is there a special "secret" warranty on this problem?


Set up an account here, enter your VIN and you’ll see a list of “Special Coverages” that apply specifically to your vehicle. 

https://my.chevrolet.com/signup

You’ll have to Google each special coverage number to find out the detailed description (this website will only show the special coverage number along with the expiration date/mileage for each coverage).


----------



## OldWhiteChevy (Mar 5, 2013)

Thanks, that's very helpful. 'Doesn't look like there are any special coverages right now, but we'll see what happens.


----------

