Hi, just wanted to ask how common is it for these PBR master cylinders to fail?
I was helping my brother in law on the weekend with his XB Fairmont 302.
He recently fitted a new master cylinder and again within a year the new one has failed... No fluid / pressure getting to front (no pressure at master cylinder even after cracking the lines) the rear was getting pressure and fluid through.

We did the works on his car as it was believe it or not all original. Car has just past 100000 on the dash back to zero.
It was a very low km car that came from a deceased estate in Goulburn.
We replaced rear wheel cylinders, pads, front rotors, bearings and pads only to find there is no pressure going to the front.

Cheers,
Damian

Try removing the brake light switch and pumping the pedal a few times to free up the proportioning valve and then try cracking the lines to the front and carefully and slowly pump the pedal.

maybe it's just the piston stuck. try cracking the master cylinder gently with a hammer while someone pumps the pedal.