My rear brake master cylinder was leaking (though there was plenty braking power), so I rebuilt it with a Magura 12mm rebuild kit. All went well until I began to bleed it.
I started to bleed from the ABS 2 bleeder screw, with clear piping and one-way bleeder valve. But about 900cc DOT4 fluid later, there was still bubbles coming out. Strangest thing was, if I bleed from the rear caliper bleeder, no bubble no matter how much I tried. I started to suspect that ABS 2 bleeder screw, but it was just a screw and there was no rubber seal in there right? What could go wrong with a screw? I also made sure I didn't open that bleeder screw too much.
Good news is my rear brake master cylinder is no longer leaking, but now I have very little rear braking. There must be some voodoo I have missed?
