Transmission fluid leak from lower cooler port in radiator

Atreus21

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02 Rendezvous CX 177k miles.

I replaced the radiator about 6 months ago and since then a significant transmission fluid leak has developed in the lower cooler port in the radiator, which you can see here.

Now, the leak you see there is actually much slower than the leak I see most of the time, because the line has play in it despite being held in the port by the C-clip. If you push it in, the leak slows to what you see in the video. But pull it out a bit, and it ramps up quite a bit. I noticed that the top line has no play in it at all.

Why I'm dreading this: It took a ridiculous amount of effort and crying and moaning (documented here) to get the damn radiator into place with the cooler lines attached. It seems to me the most obvious fix is to replace that port, and I so happen to have the previous radiator I destroyed to scavenge a port from. But I'm scared to death I'll strip the female side again and have to replace the whole radiator for the third time.

Anyway, if it's gotta be done it's gotta be done. What I want from you guys is your opinion on whether or not the port itself is to blame.

Thanks fellas.
 

MelsRegal

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Any chance it uses an O ring and you installed the old one or the new one is a different diameter?
 

2007LucerneCXL

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2007 Lucerne CXL. and 1995 Lesabre currently, past 1973 Riviera, 1968 Riviera
It looks from the video, it's back feeding through the transmission line not the radiator. The line may be the issue and not seating, some aftermarket radiators have transmission line adaptors that come with them. But it is hard from a video is this is the problem as I can't tell if the line or the nut may have bottom out, it appears most likely the nut has bottomed out leaving the line loose. Just something to consider.
 

Atreus21

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Any chance it uses an O ring and you installed the old one or the new one is a different diameter?

There was no O-ring to install. The tube is supposed to push into the port until the C-clip engages and locks it in place.
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Atreus21

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It looks from the video, it's back feeding through the transmission line not the radiator. The line may be the issue and not seating, some aftermarket radiators have transmission line adaptors that come with them. But it is hard from a video is this is the problem as I can't tell if the line or the nut may have bottom out, it appears most likely the nut has bottomed out leaving the line loose. Just something to consider.

Well, I was debating dropping the money at Rock Auto and getting the AC Delco OEM replacement radiator for $150. I truly think if I try to change the port itself, I'll just strip something. And even if I don't, I may not fix the problem. That aluminum strips so easily.

Maybe this whole thing is a cautionary tale against buying aftermarket radiators.
 

2007LucerneCXL

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If the line is the issue getting another radiator may not solve it, just a observation.
 

Atreus21

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If the line is the issue getting another radiator may not solve it, just a observation.

How could the line be the issue? It's not challenge just an honest question. I mean it's a metal tube with a lip on the end. Outside of a hole there's nothing to leak from, unless it's fundamentally misaligned somehow.

I appreciate your input.
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2007LucerneCXL

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From the video it looks like it's coming out of the line by the clip, MelsRegal posted the O-rings and clips kit, inside the quick connect is a O-ring on most GM quick connect transmission line. Most quick connect female fittings are available with the the new O-ring or go with MelsRegal as it's recommended to not reuse the clips.
316OmfAXwJL._AC_SY400_ (1).jpg
 

Fixme

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Hi guys. This is the 1st time I own an American car - usually German. Looking underneath the car I admired a lot of the engineering, but it seems like the transmission fluid is pouring out while the car runs. It stops when engine stops. Any ideas? I tried to upload a video to YouTube here:
 

TollKeeper

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2005 Buick Rendezvous CXL Sport Plus
Thats not a good leak to have. The tranny and engine are going to have to be pulled, to either have a new tranny pump seal put in, or, tranny replaced.
 
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