Replaced Radiator, now leaking Transmission fluid?

[mustanglover32]

I finally finished replacing my radiator and got everything working except for the transmission cooler lines into the radiator. Even after tightening both fittings transmission fluid still managed to leak past the threads on the fittings in the picture.

It appears to me, by looking at the old fitting that it might have been sealed by something like teflon tape? I can't think of any other reason why it might be leaking; I even checked to make sure that I didn't cross thread the fittings. There is zero chance that I did that because the fittings were all seated straight. Any ideas? I have to have this thing road trip ready in 4 days.

Thanks in advance,
david

 

[JDraper]

The old fitting had a layer of sealant built into it (the red area). You can use teflon tape or silicone rtv on the new fitting to help seal it.