I completed a full replacement of all four sets of brake pads and rotors on my 1989 240 DL. Prior to the repair all brake action was normal. Now I am experiencing a soft brake pedal or spongy brakes. I bleed the system beginning in the right rear, then left rear, then right front and finished with the left front. I replaced the brake master cylinder and still have a spongy pedal or soft brakes. I need a some help as I can't figure out what is wrong?