I've done Volvo brakes 10 or 20 times and have never experienced this (OK, well once when I got 2 calipers for the same side and one bleed screw was at the bottom and not the top). I had my son do these front brakes - he's been driving it. He said at first he got all air out but had trouble with bleeding one rear caliper. The pedal went to the floor when he test drove it. He re-bled the brakes and still no good. I thought probably the seals on the MC were ruined, so I got a new ATE MC from FCPGroton. This morning I re-bled the brakes (after bench-bleeding the MC), and still no pedal. Got a little air from one caliper but basically no air. I've been tapping the junction box but still poor pedal and brake failure light. Do I need to re-bleed after tapping junction box? What else could it be? Booster failure would just require higher effort and not brake failure, right? There appears to be a rear brake regulator, I tapped that too. TIA.