Ok so I have a '96 Jetta GL 2.0 w/ drum brakes. Last week I lost pretty much all of my break pressure and the pedal just kept going to the floor. Thought it might have been a fitting because I just had the two rear lines to the rear proportioning valve replaced. Found fluid coated on the valve itself; So bypassed it. One new line coupled straight to the passenger side. And the driver side was extended into the hose. Ok so after doing that, rear bleeder screws both snapped and even with taking the lines off of the cylinders, couldnt bleed the system out. So I replaced both cylinders, and bled and bled all four wheels. Still have air in the system and I'm not seeing any leaks. Could this be because I need that valve and cant bypass it since I believe this is where the problem started? Or Could I possibly have a bad master cylinder? Appreciate any info on this. Thanks, Ed.