It is an aftermarket MC, which I am about to replace. I was not quite satisfied with the bench bleed. This problem surfaced before replacement of the MC. No recent brake maintenance was performed. Problem suddenly presented itself while wife was driving. She stated pedal travel was excessive, had to pump to stop but pedal was almost to the floor.
First attempt to bleed, showed little or no fluid at the wheels.
After that procedure, we lost all pedal pressure. Replaced the MC. No change. No fluid loss anywhere, and Booster is working. Do not believe this is an ABS problem, as I understand we should at least have front brakes even if the ABS fails. I will replace the MC again tomorrow, hopefully with a good bench bleed. Then try to obtain a unit for power bleeding of the system.
THX for your input.