New Transmission Cooler line leak... - The 1947 - Present Chevrolet & GMC Truck Message Board Network

slategrove · 07-10-2009, 02:28 PM

Just bought new transmission cooler lines (and thought the stainless steel would last longer) so I spent the extra $ and got SS. Install was fast and easy (knew it was too good to be true) but now I have a small leak at the bottom line where it attaches to the radiator.

I know that stainless isn't going to be as soft as, say a brass flare, but I don't want to over tighten, but I unhooked it, wiped any debris that may have been there out, and re attached just to have a slightly slower leak still in the same place. It looks like it's coming from where the line goes through the fitting and also appears to be leaking from the seat that looks like it threads into the radiator.

Does someone sell the seat that threads into the radiator?

Is there something like "Stop Leak" that I can safely use in my transmission fluid?

Sammy · 07-10-2009, 03:41 PM

Worth a shot give a rad shop a call.

4x4Poet · 07-12-2009, 01:35 AM

Sounds like you still haven't ascertained if the rad female fitting causes the leak or the SS line male fitting. BTW, SS lines don't necessarily have SS fittings.

Besides a thorough check, one can run a pipe thread tap to clean the female fitting's threads.

slategrove · 07-12-2009, 06:05 PM

Quote:

Originally Posted by 4x4Poet

Sounds like you still haven't ascertained if the rad female fitting causes the leak or the SS line male fitting. BTW, SS lines don't necessarily have SS fittings.

Besides a thorough check, one can run a pipe thread tap to clean the female fitting's threads.

4X4Poet,
Thanks, I'll try the thread tap tomorrow...it's hard to tell if both the line fitting and the female fitting in the radiator are leaking, or just the fitting on the SS line. It's a super small leak, and I can see it coming from between the SS line and the male threads. Trouble is, it's not fast enough to even drip, so I can't tell if the leak is coming out of the Line fitting, and running down the radiator (making it look like the female fitting is also leaking), or if there's also a leak from the female fitting on the radiator.
I know that the SS line doesn't mean a SS thread, but it does mean a SS flare right? The flare is what makes the seal by conforming when you tighten down the thread, right?

It's a very, very slow leak and was able to tighten even further today after driving the truck for about an hour...now even slower leak.

Sinister · 07-12-2009, 06:53 PM

I had a small leak like that on a rear brake line on the '72 I used to have. I put a little teflon tape on the threaded fitting and no more leak. Worth a try.

slategrove · 07-12-2009, 08:34 PM

Teflon didn't do it...tried that already. Seems like the flare isn't seating properly. Thanks for the suggestion though.

07-10-2009, 02:28 PM	#1
slategrove Registered User Join Date: Apr 2009 Location: Normal, IL Posts: 138	New Transmission Cooler line leak... Just bought new transmission cooler lines (and thought the stainless steel would last longer) so I spent the extra $ and got SS. Install was fast and easy (knew it was too good to be true) but now I have a small leak at the bottom line where it attaches to the radiator. I know that stainless isn't going to be as soft as, say a brass flare, but I don't want to over tighten, but I unhooked it, wiped any debris that may have been there out, and re attached just to have a slightly slower leak still in the same place. It looks like it's coming from where the line goes through the fitting and also appears to be leaking from the seat that looks like it threads into the radiator. Does someone sell the seat that threads into the radiator? Is there something like "Stop Leak" that I can safely use in my transmission fluid? Last edited by slategrove; 07-10-2009 at 02:29 PM. Reason: spelling

07-10-2009, 03:41 PM	#2
Sammy Registered User Join Date: Apr 2000 Location: Bonne Terre, Mo Posts: 3,005	Re: New Transmission Cooler line leak... Worth a shot give a rad shop a call. __________________ '69 Chevy Long Fleet & '71 GMC Short Step & Project "ODD BALL" "You can wash a pig, soak it in most expensive perfume. In the end it is still just a pig." ODD BALL build thread http://67-72chevytrucks.com/vboard/s...d.php?t=478629"

07-12-2009, 01:35 AM	#3
4x4Poet Registered User Join Date: Nov 2004 Location: "Under Montana skies." Posts: 1,836	Re: New Transmission Cooler line leak... Sounds like you still haven't ascertained if the rad female fitting causes the leak or the SS line male fitting. BTW, SS lines don't necessarily have SS fittings. Besides a thorough check, one can run a pipe thread tap to clean the female fitting's threads. __________________ '71 GMC K20 Suburban, '71 GMC K10 Suburban, '72 Chevy C10 CST Suburban, '72 Chevy K20 clunker pickup.

07-12-2009, 06:53 PM	#5
Sinister Between Trucks... Join Date: Mar 2002 Location: Los Angeles, CA. Posts: 3,830	Re: New Transmission Cooler line leak... I had a small leak like that on a rear brake line on the '72 I used to have. I put a little teflon tape on the threaded fitting and no more leak. Worth a try. __________________ Beat it to fit, Paint it to match...

07-12-2009, 08:34 PM	#6
slategrove Registered User Join Date: Apr 2009 Location: Normal, IL Posts: 138	Re: New Transmission Cooler line leak... Teflon didn't do it...tried that already. Seems like the flare isn't seating properly. Thanks for the suggestion though.



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