bleeding rear brakes, fluid not coming out?

[JURO]

So i tried bleeding my rear brakes at the bleeder valve, but dry, not a drop.
Lines were rusty so i removed them.
Almost at the master cylinder, still no drops.
What gives?

The front brakes were bled as normal, have good pressure.

 

[JURO]

what if I remove the proportioning valve?

 

[chopperman1]

vacuum bleed them