Bobkat
1979 x1/9
I just went through this. Had a pressure bleeder. Might Vac for a bit of vacuum off the res. Move a lot of brake fluid but still had the air in the master. What worked was pedal held half way down, 100ml syringe pushing back through the slave spring off, but with the rod on the slave loosened and pulled out slightly. It seems with the design of the slave if it is in resting position it blocks most of the fluid/air from moving at all and if a little moves it is so little that it will never move that air bubble in the master. After the res is full then a traditional brake bleed back through the nipple to remove the last air bubbles. I also found that my replacement line to the slave had a bit of uneven surface so the copper crush washers were not sealing. Even a tiny weep here will make it impossible to get a good bleed. I replaced the washers but sprayed them with copper spray gasket first to take care of those little machining issues on the line banjo end of the hose.
I think all of this has been covered here on the forum but took me a while to find what worked for a completely empty system.
I think all of this has been covered here on the forum but took me a while to find what worked for a completely empty system.