Replaced my radiator, prior to that I had a coolant leak from around the transmision fitting.

Now, my bottom line is leaking transmission fluid. I'm 90% sure it comes from where the line threads to the fitting but it could be from where the fitting threads into the rad. It is a slow leak,only when warmed up, like getting a cut on the arm and blood oozes out.
I called spectra and obtained 15ft/lb as torque, which I set to with no change.
I've swapped the fitting from the top and bottom line but I still leak at the bottom. That tells me the leak is either due to the line or due to the threads in the rad.
Through repeated tightening and loosening, especially from awkward angles, the head on threaded part of my transmission line is almost completely rounded out.
I've thrown out the old fittings already, shame on me, I know.
My question is twofold.
Has anyone dealt with a stubborn leak at this location? Should I try using some kind of thread sealer?
Is it possible for me to replace only the threaded part on my transmission line without replacing the whole line? The threaded part freely moves up and down the line a couple inches.

E4OD transmission
Thanks

 

I used Teflon tape on some part of those fittings when I replaced my radiator.

 

+1 on the Thread Tape

 

There is a liquid teflon that applies with a brush, does the same job with 0% chance of tape strands contaminating the fluid. If it's not the fitting on the radiator that's leaking then the flare on the line is probably goofed up. Sealing the threads sometimes doesn't cut it, you may have to reflare that fitting if it's deformed that badly.

 

Bought "rectorseal" "pipe thread sealant" from home depot today. Will fool around with it over the weekend and will update.

 

Seems to have worked, thanks!

 

Keep an eye on it in case it seems later.