Touchy Tranny Fittings?

buick
century
transmissions
radiators

#1

I’m wondering if anyone else has had trouble with the quick disconnect transmission line fittings on a GM radiator. I did a radiator job on my 2000 Buick Century 3.1 L, and the upper fitting on the radiator leaks, especially bad when trans fluid gets hot on the road. The lower fitting may be leaking too, hard to tell, fluid from upper fitting covers lower fitting connections. Everything looks proper, I heard that “click” when I fit the flairs into the fitting sockets. I wiggled flares around pushing in on them slightly to try to make sure none of the 3 little latches failed to snap into place (If that was what was wrong, and then I got all 3 of them to latch, I’d be lucky). The threads on the fitting socket going into the radiator are tight enough but not crossthreaded or stripped.I don’t think they are too tight.I even put the old, undamaged fittings from old radiator in new radiator in case the reverse flair fitting on the transmission line for some reason wasn’t seating perfectly in the new fittings. Still leakage at upper fitting. The reverse flairs look ok to me but maybe they got a bit distorted? I don’t remember ever working with these kind of quick disconnect fittings before on a radiator… This is the type that has that nylon ring that clips onto the connection as a dust shield. Is this connector really that touchy, sensitive and prone to leak-out, I wonder. So many repair operations have their things to be careful about, like making sure a thermostat is perfectly centered and seated in it’s recess in the housing.


#2

They caution not to reuse any of retaining rings that were removed from the quick disconnect fittings.

But require that they be replaced.

Tester


#3

Thanks, tester, I did use the original clips but will switch to the ones in the new fittings. Would be great if this is the problem. My particular fittings are the type that are just the reverse flair on the tubing going into the chamfer in the fitting, no O-ring. I sure wish this were the O-ring type though, wouldn’t be so touchy, I think. Could I buy O-ring type fittings that my tubing’s flairs would work with?


#4

Referred to as Jesus clips in my experience, Get a couple of extras because wile putting them on it pops off, Jesus where did that clip go


#5

Yes indeed. when little things like that get lost, and they want to fall down and hide somewhere so bad, all one could do would be to say “Lord, only You know where that thing went to, please help…”


#6

I got up close and personal with the easy to see leaking upper fitting, had the engine running, and to my surprise, it isn’t the disconnect with it’s touchy looking flair connection that leaks, it’s where the quick disconnect’s socket fitting screws into the tapped hole in the radiator side tank. there is no o-ring there either to seal, just a thin flair chamfer in the fitting, which tightens down on a reverse flair in the threaded hole on the radiator. I had inspected that the other day, and it all looked perfect. And as I had said, I even used the original fittings from the old radiator to be sure the fittings would mate properly with the flairs on the tubings. So I don’t think the new fittings were machined wrong. I’m thinking the reverse flairs in the radiator hole may be machined wrong, at least on the upper fitting. I want to get fluid to stop coming from it before i look into if the lower fitting is leaking, and not just having fluid drip around it from the upper fitting. An unpleasant task, removing this new radiator I just put in last Saturday, and trying to convince the aftermarket auto parts store that the radiator is at fault in this leak issue. Maybe it would show up if the fitting were screwed into the hole with Prussian Blue on the chamfer to see if it transfers completely to the reverse flair, indicating a possible misfit with the seal.So I’m going to see if I could find a neoprene o-ring just the right ID & OD to fit on the outside of the flair seal to seal this leak. I’m wondering if anyone ever had this type of issue as described in this post, and was able to do something simpler and quicker than “pull the radiator again, take back to store for replacement”. (sure not simple in late model cars, so much isn’t simple anymore) There could be a whole batch of radiators made flawed like that. I ordered hats online once, and when I got them they were made differently than the picture in catalog showed them to be, which is what they looked like when I had bought the same type hats a few years earlier. Thought they were flawed, sent them back, reordered replacements and got the same flawed design hats sent to me. I gave up and gave them to a rummage sale. Fortunately, a local store started carrying the exact hats I was trying to order online.


#7

I’ve always used teflon tape on those fittings that screw into the radiator.

Yosemite


#8

I used teflon tape also. But I had a big surprise last night…I looked at this leaking fitting even closer, and found that it does indeed have a little O-ring down inside of the bore of it to seal on the tranny fluid tubing in front of the flare! I had thought the flare on the tubing made the seal. So, no more thinking the quick disconnect is so touchy and leak-prone. Then, I wanted to get an O-ring with the right OD and ID between the fitting and the socket it screws into in the radiator but couldn’t find the right size, and rather than spend more time and difficulty finding the right size, I tried making a mini flat gasket with neoprene rubber using my hole punch tools. To my surprise and relief, I was able to make it with the exact OD and ID I needed, tested the gasket for proper centering, looked at it, there was a narrow groove centered between OD and ID made from the edge of the fitting screwing down on it. I made another gasket to be able to put an unmarred one in the connection (how many times in repair manuals do we see “discard used gasket and install a new one”?) The fitting hasn’t been leaking at all since I installed the tiny gasket. And I find that the lower fitting doesn’t seem to have been leaking. So I hope after strenuous driving that makes the tranny heat up more, my leak issue is over.