Well it happened... while driving home last night, as I step in my clutch to up-shift, the pedal fell to the floor. It raised back into place via return spring. Pumped it a few times but no feeling until about an inch from the floor. It still allows me to fully disengage the clutch but grabbed almost immediately upon removing pressure. I could still drive it 20 mins home. And it engaged at every stop. No leaks. No sounds except the sudden engagement. I was amazed it still shifted smoothly regardless that my drunken passenger was in full panic mode. Any thoughts? 23k miles. I’m hoping it’s a build up of air in the line. I did forget to purge it when I purged the brake system a month ago.

 

I flushed the slave, just flushed the master. The clutch feels soft and it still will disengage. The vantage can move but there is severe slack in the peddle. Say it feels like more then half the throw of the peddle is slack. The last 2 inches is where it actually has a “soft” feeling where it moves the clutch. In Laymans terms it’s scary. I’ll get the vantage up to speed to shift. There’s an initial original feel all the way at the top. But as soon as i step it in it suddenly falls to that very soft disengage spot and for the love of me, I cannot get that smooth clutch shift I so desire. I’m going with the master has and is failing. A absolutely no drips or signs of moisture under the torque tube or bell area. No loss of fluid.

 

From experience on other cars I'd say most likely failing master cylinder.
You will see no leak as its leaking internally inside the master cyl.