Replaced my clutch and it worked great for about 3 weeks. on 2000 Chevrolet S10

Replaced the clutch and slave. Flushed the line with mineral spirits, chased with dot 3 and bled. A complete success thanks to some help from you guys. 3 weeks later (yesterday) The clutch gradually begins to release very close to the floor making it tough to engage gears. Nothing at the top half of the pedal as if it were not attached at all. This morning back to normal. Until later in the day after a few miles. Shut it down to, say grocery shop, then the clutch feels normal again. The fluid level hasn't moved at all. WTF?

Asked by for the 2000 Chevrolet S10
sounds like the clutch master is failing.

Ah man.....I didn't want to hear that. That's another GW and a day for me. Thank you though. I needed to hear it from you before I started the "try the easy stuff first" before spending the money and time. It's raining and I didn't feel like bleeding the clutch again first unless you said so. I'll get the master this weekend and proceed to get down and dirty. I might have more questions as I get into it so I'll thank now and again for your help. You really have been a great help to me Roy. Wish I could buy you beer. Mark
not a problem, glad to help