Help! Recurring clutch problems!

I have a 1992 Chevy Silverado. One morning I went out to start it and when I stepped on the clutch, it snapped to the floor like something broke. There was no pressure.

I replaced the clutch master cylinder, which appeared to be cracked and bled the line. It worked until…

Two months later I had the same problem. I replaced the master again (seemed to be cracked), then couldn’t bleed the air out so I replaced the slave cylinder and it worked until two weeks ago. That’s when it happened again!

It was making a grinding sound upon starting and was difficult to start before the clutch pedal “snapped” to the floor.

Any ideas?