The last week or so, I had been having issues with soft and weak brakes. I checked everything out and determined it must have been the master cyl, so I ordered one, and installed it. Old one was gunked up, leaking and in shit shape. I bench bled it, installed it, and flushed/bled the brakes at each wheel as well as the master cyl before any of the wheels.
I noticed it's gradually softened up again. It's intermittent though, sometimes worse then others. Out driving in the rain today I slammed the brakes, and when I got on the brakes next, I noticed it went almost all the way to the floor before I got enough braking power to stop the car.
I got it home, and checked the fluids. Topped off still. I opened up the bleed screw on the master and bled it a little bit, got a few tiny bubbles out, but not hardly anything. I drove it and it was super stiff and powerful as hell, but again, first time I stepped on the brakes it was soft again and I had very little braking power.
Only thing I can think of is that there may be an air lock in the master. Input and suggestions?