Took me hours to bleed my lines after replacing the rubber lines with stainless steel..

After I was sure that all the old brake fluid was out of the system, I used my own version of a speed bleeder (aquarium air line check valve) with aquarium airline......

Wrap teflon tape around the bleeder threads so that there's no way air can enter system.

Run the airline tubing from the bleeder screw (after check valve) back to the master cylinder.

You recirculate the fluid until there's no bubbles in the tubing.....