I have four piston calipers. I replaced basically every part of the brakes. Also, I added a power booster. I bench blead the master cyclider and blead all four wheels using speed bleeders.

When I rebuilt the calipers, I seperated the caliper halves, removed the seals and pistons, coated the cylinders with brake fluid and instlled the new pistons and seals.

I'll have to check for pre load. If that's okay, I'll pull the pads and see if the pistons are moving back and fourth as they should.

Its strange that just the inner pads are having the problem though.