Check the lines too, might have a leak as well, in the hard lines or the rubber, or at least a weak line.
I had to replace both front rubber lines on my old 1987 GT, it had horrible brakes when I got it. I found that my rubber lines between the caliper and the hard line had broken down and were bulging when pressure was applied to the pedal, causing a "spongy" feel in the pedal. If i'd waited another day i think it would have been it for me, they may have ruptured and failed. Replacing those, then bleeding out and replacing fluid until it ran clean out the bleeder valves did make a HUGE difference. Yes, it's a pain in the butt, but it's worth saving your ride and or your life to do it.