Help...master cylinder not bleeding on car

[mjordanlmj]

it was manual and converted over when I got it,.
The rod was on the upper hole and I moved it to lower,
have free about an eighth inch before master cyl, play at pedal.
when we tried to bleed the rear nothing came out,
so then we tried at the proportioning valve still nothing.
took line off at master and tried to get fluid out.
Just a rock hard pedal, figured had a bad master.
got another and bench bleed it rear was bleeding on bench,
on car rock hard no fluid out, thinking that the booster is the broblem.
even used different length rods at master still nothing.
What am I missing, thanks for your time.