96 Passat Clutch, Maybe Problem w/ Reservoir?

Was having problem w/ my clutch pedal going all the way to the floor and staying there. Started infrequently, then got worse. Finally, pushing pedal in would not disengage clutch at all. First replaced master since slave didn't look like it was leaking. Once I did that, I couldn't bleed the system. Thought maybe slave WAS bad after all, so changed it. Now I STILL can't get the system bled. No fluid AT ALL is pulled through the system. Pulled flexhose between reservoir and master at the reservoir nipple. VERY small drops of fluid coming out. Tried pulling vacuum at that point, and all I get is a sucking sound, no fluid, no vacuum build. Seems like my reservoir is funky! Anyone ever seen anything like this? The reservoir looks like it will come off of the metal body below it. Should I remove and replace or remove and flush? Please, anyone's thoughts or experience!

Garry, how many miles?

236,000. Original clutch. And I know what you're going to say, probably. Pressure plate? But I don't think that addresses the hydraulic problem I am having. One more piece of info. When I pour my DOT4 in the reservoir, there's "sediment" or "flecks" floating around inside. I'll eventually bleed the entire system (clutch and brakes) but need to get this clutch hydraulics problem fixed first.

Oh, yeah. ALmost forgot. Don't really know if this means anything, but the rod on the new slave was a good 1/4 - 1/2" longer (more extended) than the one I removed. And I'd guesstimate the new slave rod made contact inside the housing about 1 - 1 1/2" before the flange was tightened down.

Does anyone know how the reservoir disconnects from the metal base? There appears to be a small plastic strap holding it down on the driver's side. I'm guessing (haven't looked) there's another one on the other side, but don't know if these are the only two connections.