Not sure, the master cylinder still has plenty of brake fluid in it, pedal just suddenly went to the floor and won't pump up.
Scared me enough to just overhaul the system. I don't trust the "powermaster" brake booster for one thing, and the lines look pretty rusty.
Still has a PowerBastard, eh?
Yeah, that's not the shop's fault. Those things were timebombs when new. Put a vacuum set up on it and call it a day.