New Master Cylinder and can't get air out of one brake line

mycuda said
In the past, Ive just crack open the bleeder a bit, on the suspect line and let it gravity drip
making sure you keep fluid full on MC. Sometimes overnite. Always had improved results.
That is, if you dont have any tiny leaks.

D.

Forgot to mention, keep MC cover off or loose. Air bubbles escape from both ends of system. Then do the routine bleeding process.