As the title says, just replaced front pads (used prroper tool to depress piston), brakes were a little spongy before changing but I had assumed that was just rear adjustment (adjusted now). I thought I'd messed up the MC by depressing too far while bleeding so I replaced it (bench bled as best I could) but still having the same issue. Brakes go basically to the floor, the can be pumped up but go back to floor if the pedal is reset. Completely firm if the handbrake is engaged. I'm assuming this might mean bad piston on one of the front calipers, since engaging the handbrake might shift it in such as to cause a better seal, but there no sign of a leak (even within the rubber boot).
Open to any suggestions of what to look for next, I keep hoping it just needs more bleeding, but the fact it goes firm with the handbrake has me stumped.
Thanks