Ever since I got my 1999 v70 T5M a month back, the brake pedal has been strange. It felt kinda like air in the lines--when you'd push it would go down quite a ways, but if pumped quickly a few times it would really firm up. Braking was always strong, just sometimes the pedal went a ways before working.

I went to bleed the brakes a few weeks ago and (naturally) the front bleed screws broke right off. I bled the rears and it seemed like things were a bit better (placebo probably...).

Since one of the parking brakes was not working, the pads were only 1/3 left on the rear, and the rotors didn't look to good back there, I just replaced all four calipers and the entire rear brake assembly, including parking brakes, rotors, and pads. I also did the front brake hoses.

I bled the brakes three times with my pressure bleeder, just to be safe. When I went to firm up the pedal with the new calipers on, the pedal traveled a long ways a few times until the caliper cylinders pushed the pads against the rotors. I then bled once more (I'm anal).

Now, with the car on, the pedal goes right to the floor and there's no braking at all unless I pump the pedal a bunch. I even bled one more time to make sure there's no air in the system. I definitely never let the master cylinder run dry.

Basically, I'm left thinking it MUST be the master cylinder with an internal failure. There are no leaks that I can find anywhere on the car, but there's no braking. Does this sound likely/probable? I don't want to buy a new MC and install it only to end up at the same place where I am already. Could anything with the abs module cause this?

Thanks!

Nate
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1997 850, 1979 242GT, 1990 740GL