Clutch failure in my Kia, working through the slave cylinder.

I recently had to replace the clutch in my 2009 Kia Specta. No great issue, it was just old and worn out. Well, a few days ago the clutch failed. I thought maybe it was a failure in the slave or master cylinder but...no. It looks like the throwout bearing has come disengaged from the pressure plate.

In the Kia, the clutch is a "pull type". After installing clutch and pressure plate, you install the throwout bearing on the transmission input shaft, making sure the forks are engaged in the "ears" on the bearing. After you reconnect the transmission and clutch to the engine block you work the actuator backwards to engage the throwout bearing with the pressure plate. You have to do it that way because once the two are connected it's permanent. The throwout bearing locks into place and, well, I haven't figured out how to release it from the clutch I removed so it's pretty permanent. There is no way to install it "wrong" where it works at all. If it works at all, it was done right.

After the failure, I had the car towed home and dug into it a bit. I was able to disconnect the slave cylinder and force the actuator lever backward. I felt the throwout bearing engage with the pressure plate which was a surprise. And it seemed to hold against hand pressure anyway. However, on reconnecting the slave cylinder and pressing the clutch pedal I found once more that the clutch would not release.

The vendor of the clutch "suggested" that maybe the reason I lost the ability to shift as a result of a problem with the master cylinder or slave cylinder. However, as this video shows, the slave cylinder does move in response to depressing the clutch pedal. But note that it first makes a big move, then doesn't return to the original position. It's the "pull" of the pressure plate operating through the throwout bearing, fork, and lever that pushes the shaft of the slave cylinder back into place. It's not getting that force.

Clearly, the problem is with the pressure plat..