Leaking antifreeze

I'm leaking antifreeze from the 5/16" aluminum lines that run from each head to the rad.. I don't have any pics but does anyone know what i mean off hand? i 'm just wondering what the hell gasket to ask for??? I tried tightening the nuts on top a bit but there's still dex-cool sitting down in that area when i check it out after running it for a while.thanks i'll try and get pics posted soon.

they are the front steam lines. there is a small pill shaped flat peice of metal with two holes in it under those mounts, one hole is for the bolt and the other hole should have an "O" ring in it.

take the line off and smear alittle black RTV around the "O" ring hole

Thanks..will do