Disc Brake problem 72 Swinger

I have a 72 Swinger with 4 piston caliper front disc brakes. Last night I installed new rotor and caliper on the right front, and new pads both sides. I could not get the caliper pistons to release on the outside of the left front without taking the brake lines loose and releasing them. I did that, bled the brakes and it seemed to work fine. This morning the brake lights were on, and I belive there must be something holding the pressure in the lines, causing that right front caliper to hang up in the first place and the brake lights to stay on. Any ideas?