oh my brake problems.......

[67chevy1series]

well today i was going to bleed my brakes for the first time... took the prop valve off bleed the air out of the master cylinder... after that i started with the back brakes ot those done moved to the front and its leaking in between the brass block and the caliper... what do i do?
heres the statistics:
new:
calipers
pads
all the hard lines
rear wheels cylinders
brake shoes
old:
drums
rotors
and the fronts and rear rubber hoses, all of these items are perfect nothing wrong no need for replace.

for those that are having a hard time figuring out what i am talkin about heres a diagram: