brakes leaking air

[tysonbully2k12]

So there is air coming from where the brake pedal is,
Been happening for awhile,

Every now and then the brake pedal will slowly go to the floor,
I have to slightly touch the pedal to stop it hissing air,

Do i need a master cylinder or the round thing behind that?

[Piggy]

Check the pipe from vaccuum to servo

If thats fine, it could well be the seal between servo and MC

[pug306driver]

pedal goes to the floor slowly......how is the fluid, all black??

when it goes to the floor, does the fluid in the master cylinder res rise slowly?? siuggestijng an "internal leak" in the master cyl......or is fliud leaking from the system.......or running down the servo from where the master cyl bolts ( nuts ) to the servo.........

air hiss by pedal, air leak into the servo at pedal end..........bad filter?

[tysonbully2k12]

So i had a look and its its hissing from the picture i uploaded,
Tiny bit of brake fluid on the plastic bit.