I accidentally pulled on the brake when the calipers were off the rotor. I had to take the pads off and squeeze the piston back with a C clamp. Now, when I reassembled it, the piston won't move.
I disconnected the hose and put more fluid in the reservoir, and it squirted out when I squeezed the lever. So I know that at least it's pumping fluid thru the hose. When I connect the hose to the caliper, the lever doesn't build up any resistance. ???