Not a fluid problem.
Did you rotate the rear caliper piston when you pushed it in? The front calipers can be pushed in but the rears need to be turned as they are pushed in. There's a ratcheting adjuster inside. After you do a brake job, pump the brakes 3 times and pull the e-brake handle 3 times. My guess: the e-brake is engaged and is causing the rear brakes to drag.
When you do a brake job and push the brake pedal all the way down to the floor, it might wear the seal a little since the pedal never goes that far into the cylinder. I doubt this caused any problem and 99% of the time it does not. If the seal was bad, the pedal would sink to the floor, not be high.