This is more of my first real brake troubleshoot job. It is turning out to be more complicated than I would like.

My brakes had too much travel so in the process of bleeding I found the right rear rear rotor on one side was worn slanted. I replaced both rear brakes with new rotors and rebuilt calipers with pads. Then I bled around the car left rear, right rear, right front, left front. I bled the lower nipples first, then the uppers on the front caliper. To bleed I drilled a hole in a spare brake reservoir cap and screwed in a brass tube fitting. I fill the reservoir, attach 1/4" hose to the fitting, and put a compressor set to ~20psi on the other end of the hose. Things flow fine. The total amount of fluid we bled was about 6 oz, evenly from each 4 brakes. Was this not enough? What is the total volume of liquid in the lines, approximately?

Symptoms now are still too much brake travel. I held the brake pedal down, started the car, and the pedal sank, but too far. (The booster test) The brakes seem to work fine except the travel is excessive, but does not hit the floor. I can also hear the front left wheel or brake squeaking with car speed. If I lightly use the brake the squeak seems to go away. The car also pulls a little under heavier breaking. This seems like it could be a million things, some of which relate to suspension components.

There used to be a vaccum leak coming from under the dash, but seems to have gone away. It may have been just that I had the vent control in the middle of a couple of settings or something like that.

My ideas are air somehow still in the system. Some stuff seems to suggest you have to separately bleed the master cylinder to get the air out. I didn't understand how it works, since it involved cracking the MC exit lines. Why not just let the fluid/air flow into the rest of the system and bleed that air out later. Here is the whole procedure:
Before you pull the MC to bench bleed, try this:
1. Get something that will block the pedal in the down position eg. wife.
2. Crack open lines at MC exit.
3. Depress brake pedal and block it in the down position.
4. Tighten lines.
5. Release pedal.
6. Check for pedal firmness. If firm then air is out. If not, repeat from step 2.

Another idea might be the check valve, but I don't know why.

Other diagnosis I might try is clamping brake fluid hoses one at a time until I eliminate the problem. However since I only have excessive travel with the car on, is it safe to clamp lines while the car is running up on car stands?

What sounds like may be wrong, or have I not sufficiently bled the system?

Thanks,
Nathan