Get an eezibleed,put tubes on all four nipples,connect to spare tyre with 40 psi in it,undo all 4 bleed nipples one after the other (so they are ALL open) but ONLY just enough so brake fluid comes through.Start undoing them at passenger rear then drivers rear then front passenger and then drivers side front.Keep an eye on eezibleed fluid container but do'nt worry if it goes right to the bottom as you still have a master cylinder full of fluid.
Doing all four at the same time gives the air no choice but to leave the premises

You can nip the nips up at any time if you need to top up but remove pressure pipe from tyre each time you do.
Wheres that air

?.Oh,it's gone

If you still have a problem then im guessing your master cylinder is leaking through the rear seals so you will have brake fluid in your servo.
Good luck.