Leaky line

As stated, the line out of the rear of the 904 is leaking. It is a small drip at idle, and like your taking a pee when in gear. I'm going to try this again, next nice day with some time to mess around. Probably tomorrow.
I'll disconnect the line at the rad/cooler first and the connect the line to the trans. first and to the cooler second.
Does this sound like the better way?
I think I'll have better luck, I hope.

The line is new and the fitting in good shape. I raided the fitting off a 727 at the back of the garage. I was told I could get these at Lowes or Ace hardware, but there not exactly the same and hard if not impossible to hook to the hard line.

The question of the thread is, does anyone use anything to help seal the lines threads?

Signed "Getting old, stiff and tired on my back." LOL