Brake Bleeder Thread Sealant?

[dsraven]

if it is leaking at the pipe thread area of the brass fitting, where there is a red sealant on the threads of the brass, then you may just take the fitting out, check the threads for damage, install some liquid thread sealer and re-install. if it is leaking at the brake line connection to that brass fitting, then first check the flare on the brake line for cracks or distortion, debris etc and also check the seat area in the brass fitting where the flared tube butts up and seals against the brass. you may have an issue there. look for cracks, a bump or line where there may have been a piece of debris on the seat when the line was tightened. this can distort the seat and you will not get a seal and will need a new fitting. also ensure you have the same angle on the two parts, the tube and the brass seat. the brass fitting wouldn't break the bank if you need to replace it, as well as the brake line.
try not to use the tape style pipe thread sealer because it can leave little pieces of the tape flapped out into the fitting and cause issues when it becomes free floating in the brake system. especially if you have to undo the line for some reason. a liquid style, like the red style used on the assembly now, is better. don't use anything on the threads of a flared fitting connection because they are not the sealing area of the fitting. that is done with the flare and seat. the threads simply tighten or loosen the connection. a drop of brake fluid or synthetic brake grease on the threads for lube if you feel you gotta use something, but use sparingly.