Have to pump up brakes when I first start up, pedal goes almost to floor w/o much stopping power very soft pedal. Improves with a little pumping. Am not losing fluid. Air in lines?(seems like if air could get in, fluid could get out). Internal leak around piston but not at seals? Any info or suggestions appreciated.
Bleed the brake lines, and check the condition of the pads.
Yea, it sounds like a master or slave cylinder to me.
Bad master cylinder and yes, it can leak internally.