Air in the system somewhere. Bleed it from the master and then booster again while its on the car. Pump it up and then hold it down, crack the brake line fittings just like a bleeder nipple.
Then bleed as normal

air rush noise (like air hissing) when pushing brake pedal normally indicates a roo-ted master cylinder i thought

i pressume you have bled it enough, it sounds like you have had every component apart so it would need a fair bit

i have upgrade my 1200 Ute brakes
it has r31 skyline rear calipers and disc and Mazda s6 calipers and disc on front.i am running a (brand new) 240k (7/8)master cylinder and BMW 318i brake booster.
the front brakes run of the booster the rear does not.
There are no leaks that i can find and no fluid anywhere along lines

Now the problem!!!!!!!!!!
i have bench bled the master put it in and bled the system starting with further caliper away to closet.(from the master)

i have a pedal but i have to pump the pedal a few times then i get good pedal and brakes. i leave the pedal for 30 secs and then i have some pedal and some brakes.Also i get a air nose (sounds like coming from master)that only happens when i pump the brakes up but i cant find out where it is cant see or feel.

I was wondering if anyone has had this problem or has any info about what it could be.As i have bled the brakes and there is no air and no real reason why they wont work unless the air noise is the problem......need help badly

ANY INFO WOULD BE A GREAT HELP AS THE CAR IS FINISHED JUST NEED BRAKES TO DRIVE FOR FIRST TIME IN YEARS