brake bleeding problem

Im bleeding the brakes manually with 2 people and with the brake vacuum bleeder with compress air. Problem is that the left/rear side the fluid barely comes out. I sucked it out for 10mins with the vacuum bleeder connected to my air hose and still the same. i took the brake hose line off to check the screw and washers (all good) its just this side that it will not fullly come out of. replaced brake booster already. My next step is going to be the master cyl. I read somewhere that if it might be clogged?

Are you sure its not a bad hose? Its pretty rare but I have had a handfull over the years that the hose has been collapsed. If you can get the brake line off the other end to see if there is good flow or not.

when i took the hose off the caliper i had my second man slow push down the brake pedal and there was fluid coming out not a whole lot though.