1986Brat

Half way through a drive I noticed that I had to depress the brake pedal much farther before braking began (they worked fine when I pulled of of my driveway). The brakes acted as if they needed to be bled. I didnt get around to it and a few days later the left rear wheel cylinder broke and by the time I made it home all of the fluid had leaked out of it. I replaced both rear wheel cylinders and brake shoes and bled the brakes at the master cylinder and all wheels in the correct order. Yet in order to get any braking power, i still have to pump the pedal 6-8 times and even then it sucks. Sometimes it pulls hard to the left, sometimes it doesn't. Needless to say, I won't be driving like this. Could this be a problem with the master cylinder? There are no fluid leaks. ANY advice would be appreciated!! Thanks!