re master cylinder update ?

brake update
went to bike this morning gently tickled the brake lever air came out up through the master cylinder port and the lever pressure increased to the point of a full pedal within half a dozen presses,(no fluid top up was needed) no bleeding was needed , lid is back on,the lever does not fade out any more,
moral of this is all the air in the pipe rose up the brake pipe during the night patient is a virtue