How do I isolate the leak?

Got it. I bench bled the MC. I checked everything out and nothing looks bad on the old MC. But its probably something I can't see with my untrained eyes. Anyways I am going to bleed the system later today and hope for some real stopping power!

What kind of silicone or locktite can I put on the brake lines before I screw them into the MC to prevent leaks and so forth? Should I use grease on those also?