Weird . . that makes 3 of us here on the forum that did a clutch job at the same time. Not sure why you lost pressure in the first place, but keep pumping the clutch pedal. It'll build the pressure back up. It takes 10-20 strokes. If not, then you might have a 2nd look at the slave cylinder. But it's definitely in the clutch hydraulics- there'll be no reason to drop the tranny again.