Transmission Cooler Quick Connector Leaking

deadbeat son

deadbeat son

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I took my '05 TJ for a drive yesterday to put some miles on it and to help break in the new gears, and evidently I've developed a slight leak at the transmission cooler line quick connector on the passenger side of the lower radiator. I've searched through here, and there is a lot of discussion about the line itself leaking where the hard line meets a soft line connection, but mine appears to be leaking from the quick connector instead. I cannot tell if it's leaking between the fitting and the radiator, or between the line and the fitting.

Is there an o-ring on the line that goes into the fitting that I should replace, or do I need to replace the entire coupler? I'm a little worried about the possibility of cracking the plastic tank when switching out the fitting. Is that concern even warranted?

IMG_5923.jpeg
 
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Peter Panagakos said:
When I ordered my new Radiator from a Jeep Dealer it came with new connectors installed. The O ring is built into the connector. The line just slides in through the O ring. Then the spring clamp holds it in place. It looks like you need to replace the connector. The o ring is probably where the leak is.
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Thanks, looks like a new quick connector it is.

LONGJP2 said:
I think this is the part.
https://www.amazon.com/dp/B000EPYHVO/?tag=wranglerorg-20

I haven't taken one out, but I thought I read the 'nut' inside the radiator can move.
Maybe someone else can confirm or deny that.

https://wranglertjforum.com/threads/04-42rle-transmission-radiator-cooling-line-fittings.35114/
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Yes, thanks for those links. I read them earlier, and everyone was trying to adapt their old style lines to the new style cooler quick connectors. I haven't found anyone just replacing the connector in an existing OEM radiator to stop a leak, but I could be missing a thread. Good to know about the possibility of spinning - that's too bad. I don't want to end up needing a new radiator just to fix this minor issue. Luckily my neighborhood Autozone has the connector in stock, so at least that part will be easy.
 
Okay, I have an update on this. First, the Dorman 800-605 referenced in this thread and others (as seen in the following picture) will not work on the OEM radiator.

image.jpeg


This coupler may work on aftermarket radiators, but not the stock radiator for an '05. It fits the line, but is the wrong thread size for the OEM radiator. Additionally, the transmission cooler has a large flange that pushes against the lower radiator tank, and the coupler has a large flange that seals off against the tank and holds the transmission cooler flush with the edge to prevent coolant from leaking out around the coupler. The OEM coupler looks iike this:

image.jpeg
image.jpeg


I cannot find the MOPAR coupler itself. Dorman lists a part number 800-703 for the TJ, but that cross references with the MOPAR 52119547AA, which is the quick coupler on the transmission end of the lines, not the radiator end.

I found 2 similar looking Dorman couplers online (with GM applications), and went to an auto parts store with them in stock, but they were way too big for the TJ application.

Since I couldn't find a correct connector, I did the best thing I could do. I pulled the old one out, cleaned it thoroughly with isopropyl alcohol (including both o-rings), cleaned the line, and reassembled. I took it for a drive around the block and there's no sign of leaks at this point. I'm not expecting the cleaning resolved it though. I'll be sure to post back here if I find a correct replacement coupler.
 
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IIRC, some have fixed this issue with screwing in a barbed fitting and adding a soft line.
Not sure of the part number.
Probably trial and error.

I wonder how many of those fittings are out there that have been swapped out for barbed fittings and/or not being used on manual vehicles?
 
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LONGJP2 said:
IIRC, some have fixed this issue with screwing in a barbed fitting and adding a soft line.
Not sure of the part number.
Probably trial and error.

I wonder how many of those fittings are out there that have been swapped out for barbed fittings and/or not being used on manual vehicles?
Click to expand...

A barbed fitting without the larger collar or flange will not work in these newer OEM radiators.
 
LONGJP2 said:
Interesting.
Rockauto shows the Mopar # as the radiator side, yet not flanged.

https://www.rockauto.com/en/partsearch/?partnum=+52119547AA
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I’m not sure I’ve explained things well, so I’m going to try and explain better but will not be accurate with my measurements, they’re just notional to explain how it all fits together.

The plastic lower tank has a 1” hole where the transmission cooler interfaces. The transmission cooler is made of aluminum and the face of it has been machined to fit into the 1” hole in the tank precisely. However, the cooler is not bonded to the tank, so coolant can leak from between the transmission cooler and the tank opening. I can push the cooler back into the tank with my finger, and coolant will gush out of the opening. The quick coupler has a 1.25” flange. When you screw the coupler into the transmission cooler, it pulls the machined aluminum face tight into the opening of the plastic tank and seals it from leaking coolant. Therefore, no connector without a flange will work. The cooler will just be floating in the bottom tank and coolant will pour out. Again, the 1” and 1.25” figures are just proxies for the real dimensions. I didn’t measure and am not laying underneath my Jeep at the moment.

With that said, perhaps the transmission cooler is supposed to be bonded to the tank and mine has failed. I don’t know, I just know I require a flanged connector to prevent catastrophic coolant loss.
 
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LONGJP2 said:
Based on the picture?

Edit:
I see now. You meant transmission fitting, and I was thinking radiator vs. tranmission line (at the radiator).
My bad.
Click to expand...

Yes, the fittings are for the transmission; the transmission end of the line connects to them, not the radiator end of the line.
 
deadbeat son said:
Since I couldn't find a correct connector, I did the best thing I could do. I pulled the old one out, cleaned it thoroughly with isopropyl alcohol (including both o-rings), cleaned the line, and reassembled. I took it for a drive around the block and there's no sign of leaks at this point. I'm not expecting the cleaning resolved it though. I'll be sure to post back here if I find a correct replacement coupler.
Click to expand...

Bumping an old thread here in case anyone else has the same issue and finds this in a search. After disconnecting the lines from the cooler, cleaning them thoroughly, and reinserting them, it has not leaked since. It's only been 45 days or so, but I believe that's enough to consider the problem solved.
 
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deadbeat son said:
Bumping an old thread here in case anyone else has the same issue and finds this in a search. After disconnecting the lines from the cooler, cleaning them thoroughly, and reinserting them, it has not leaked since. It's only been 45 days or so, but I believe that's enough to consider the problem solved.
Click to expand...

Can you explain how you removed it? Did you have to drain the transmission fluid? How much fluid cam out after you disconnected the line?
 
When I replaced my radiator and disconnected the trans cooler lines form the old radiator, I plugged the end of the lines with some plastic plugs that fit fairly well, duck taped then so they would not fall out. I did not leak much fluid. I also suspended the lines face up as much as I could and used a few shoe laces to
tie them to what ever was above them, brackets, hoses will do. The lines will drip fluid if left facing down and open. I read to do the plugs somewhere but can't remember where. Could have been one of those "how to videos" on the internet.
 
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Urban14Jk said:
Can you explain how you removed it? Did you have to drain the transmission fluid? How much fluid cam out after you disconnected the line?
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Tons come out of the ports in the trans, a bunch will leak out of the lines. Even if you've drained the trans by removing the pan. I'm dumb, it never occurred to me to get plugs for the ports on the trans or to raise the level of the lines from the radiator. Probably because by the time I've disconnected all that the mayhem of dropping a transmission is in full effect. I'm going to say I'm gonna remember that for next time but I probably won't.
 
It sounds like you are disconnecting the lines at the Transmission. You don't need to do that. Just disconnect at the Radiator, plug the end in the lines to the Trans and tie them up a bit. You won't leak much fluid that way. I assumed you were just replacing the disconnects at the Radiator. Hope I understood your question correctly.
 
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Urban14Jk said:
Can you explain how you removed it? Did you have to drain the transmission fluid? How much fluid cam out after you disconnected the line?
Click to expand...

You move the plastic cover out of the way, use a small screwdriver or similar to remove the small circlip, and then the line pulls out. I pulled it out and capped it and lost less than an ounce or two of fluid, but used a pan in the process just in case.

To reinstall, slip the circlip over the connector and then push the line back in until it seats. Push the plastic dust cover back in place and Bob’s your uncle.
 
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