Hi all, I'm new to the forum but not new to vw's. I have (among others) a 99-1/2 jetta tdi and the master cylinder went...or so I thought! I replaced it today and have the exact same symtoms, pedal slowly goes almost to floor. The ABS light is on, so now I think that's the problem, but I'm not familiar with ABS (more of an old rabbit, cabriolet, scrocco guy). I should have done more research before I replaced the master but I was quite sure. A friend told me the diaphram in the ABS(pump?) may be leaking causing the pedal to slowly go down. Again, don't know ABS at all. Does that sound possible?Any suggestions? Thanx for the help

 

Well it could only be 2 things, leaking fluid, or maybe vacuum loss, and it doesn't soud like that. I would bet that there's either a small hole in a brake line somewhere, or like you said leaking from the diaphragm. I replaced a brake line on my mom's vehicle, and you couldn't tell the line was leaking until you pushed the pedal. Excessive pedal travel is usually leaking brake lines....how much pad wear is there? Push on the pedals in a garage or something like 10 times, and then look under and see if there's any sign of fluid, if not then somewhere internally there's a leak, but you would still some fluid somewhere.