Brake bleeding, Nothing but air from rear brakes Options

[Medtner3]

Just rebuilt my rear calipers with seals from PMB Performance. Using a vacuum brake bleeder I started with the right rear caliper lower bleeder screw ( I have two screws) and initially pulled about an inch of brake fluid with lots of bubbles and then zip. I get zero brake fluid now.

What could cause this? I have no signs of any leaks and the brakes were not bad before I rebuilt the calipers. I read somewhere that I might need to bleed the proportioning valve or even pump into the caliper some brake fluid through the top bleeder ?

I ordered a Motive pressure bleeder which arrives in a few days

[Medtner3]

Damaged master cylinder or impatient? I put on speed bleeders and pumped two to three inches of fluid through each caliper staring with the traditional right rear and top bleeder only. First with Motive pressure bleeder until I did not see bubbles, then a pedal bleed, although I could not see whether bubbles came out or not. Neither one firmed up the pedal. And the Master did not go dry.

I’m wondering did I ruin the Master by pushing to the floor accidentally? !? I only did that once
??
Or is there still air in the Master or possibly proportioning valve? Confused never had so much trouble bleeding: I read another thread where more than one person said it takes four trips around the car with pedal bleeding to get a firm pedal on the 914