Funny story: Years ago I had an Audi 5000 CS Quattro 4DSD. The clutch was physically fine, but I couldn't tell if the hydraulic master or slave was bad. So I replaced both. The master was a really LARGE pain to change. The slave was pretty easy.
I tried bleeding it with a vacuum bleeder by myself. I tried bleeding it with a pressure bleeder by myself. No pedal. Then I got a friend's help to bleed it the old fashioned way. It came right up, like it should. After the job was finished, I couldn't find my 7mm combination wrench. I guess I left it at my buddy's house where we changed the parts, oh well.
I found it a year later when I was under there looking at the exhaust or something. It was still on the bleeder!