Masters frequently need priming to bleed as they air lock and will not push fluid.
(1) WEAR PROTECTIVE GLOVES
)2) cover any painted item
(3) disconnect outlet pipe
(4) put gloved finger over outlet hole and push down pedal
(5) remove and replace finger with pedal down
(6) with finger in place release pedal
Repeat (4) through (6) until brake fluid squirts out around finger under pressure
and
Finally, with pedal down reconnect outlet pipe and bleed to caliper