Transmission Cooler Line Leak

[benjamming]

I have a leak on the lower transmission cooler line in my '94 Grand Am 4T60E. What is the best way to do an in-place fix? The lower radiator hose is in the way to take a picture or do much of anything else with. The picture is, of course, of the upper connection. It is identical to the lower connection sans leak. I don't want to have to drain the radiator again to remove the lower hose. I can't tighten anymore with the crowfoot wrench.

 

[JakeR22]

Can you tell if it's leaking at the male or female side of that brass fitting?

Just replacing that fitting may stop the leak.

 

[benjamming]

can't tell due to obstructions. Note to self: get a mirror today after work.

 

[mechtech2]

Cooler lines can often be fixed by using 3/8" fuel line [injector rated].
Cut out the bad section of line [no sharp edges], and use the hose with at least 2 hose clamps on each end. Rotate the clamp heads 180 deg apart, and allow for flex in the hose when the engine rocks.

 

[Cycle Freak]

I did that as a temporary fix on my 1998 Sonoma but next spring/summer I want to replace the lines with pre bent ones from LMC truck. Does anyone know if this is possible without lowering or moving the tranny to get to where they are threaded into the side of the Transmission?

 

[nel]

The GM oil/transmission cooler lines are prone to leakage after a few years. Your leakage may be at the quick connect seal between the line and the connector on the radiator (rather than between the connector and the radiator). The part itself is relatively inexpensive, but it does require removal of that lower radiator hose to gain access.

 

[benjamming]

The cooler lines are original. The leak started after radiator replacement. I didn't use anything on the threads between the brass connection and the rad nor between the line & the brass connection. I'm wondering if I should.
Anyway, is there any kind of "goop" that can be applied to stop the leak now with it in place?

 

[RH+G]

Originally Posted By: mechtech2
Cooler lines can often be fixed by using 3/8" fuel line [injector rated].
Cut out the bad section of line [no sharp edges], and use the hose with at least 2 hose clamps on each end. Rotate the clamp heads 180 deg apart, and allow for flex in the hose when the engine rocks.


While the advice is good if you use fuel line it will get soft and mushy and fall apart. You have to use hose that is rated for trans or p/s.

 

[mechtech2]

No it won't.
Vacuum line is soft and unsuitable. But njection rated fuel line works great [takes pressure], and is not affected by trans fluid.
Pretty cheap fix, too.

 

[RH+G]

I have used Gates fuel injection fuel line to make tranny cooler line. I had the proper rubber tranny cooler line next to it. The fuel line began to leak in about a little over a year. Transmission fluid will breakdown a rubber fuel line. That is why they tell you in tranny cooler packages to make sure you use the tranny specific rubber line.

 

[benjamming]

Good discussion on acceptable/nonacceptable lines but the line itself is fine. How do I know? The leak didn't start until I replaced the radiator and had to put the new brass fitting on the new radiator for proper fit (fitting came with new radiator). The leak is from the fittings I just can't tell which one. So, the issue is the fittings and not the line. What can I use to smear around the connections to stop the leak?

 

[Gary Allan]

you may be able to stop the leak with the appropriate thread sealing agent of choice, but the threads aren't (normally,IIRC) providing the seal.

 

[benjamming]

What appropriate thread sealant agent would be the best choice here?

 

[Gary Allan]

I guess, if asked, I'd use the Permatex that was rated specifically for ATF (there is one) ..but I imagine anything that was rated for petroleum and temps of 250F would work. I won't venture how easy or tidy it will be to service the thread after doing this. Taping it, if possible, may do the trick.

 

[GMBoy]

First see where it really is leaking. If (as somebody else said) it is at the quick connect fitting that is really cheap and easy to replace. Probably is your trouble since it was obviously disconnected during rad repairs. Otherwise, there is no thread sealer used during assembly at the threaded fittings, but I guess some wouldn't hurt. I'm guessing the quick connect is your issue.

 

[benjamming]

BTW, I appreciate everyone's responses. It's good to see folks trying to help out.

The brass fitting wasn't there on the other rad. The new rad has different size connections, thus the need for the brass fitting which came with the replacement rad.

GMBoy,
I agree that the brass fitting would be cheap & easy to replace once removed. However, I was looking for an in-place solution. As Gary pointed out, that may be even less desirable. It looks like I will need to drain the coolant again and remove the lower radiator hose. Hopefully, I can catch it and reuse it.

 

[Gary Allan]

I know what you mean, though. I'm often confronted with some (what I call) "3mm too little clearance" issue. It's where you're prevented from moving a 36" wide piece of furniture (or other object) through a doorway that's just 3mm too narrow (alter dimensions as needed for scale). You're then forced to take some 200 foot path to move it a distance of 3'-5'.

Essentially turning a 3 minute job into 1 hour+ unless you're really motivated to waste labor and time willingly for otherwise simple stuff.

 

[SHOZ]

You could just get a large axillary cooler and eliminate the radiator cooler.