Pull Clutch, thrust bearing detaching from clutch plate.

[CheapMotor]

Can anyone help me my car is facing the scrap yard if I cannot work this out.
The clutch on the 406 HDI 110 is a “pull” type. I have replaced it.
I engage the thrust bearing by pushing the thrust bearing lever hard to the right ( in turn this pushes the thrust bearing to the clutch plate ).
I hear it click in, this is confirmed by a visual check with a tourch, if I press the clutch pedal this operates the clutch correctly.

This is the problem, if I press the clutch pedal a few times the slave cylinder jacks out and due to the pivoting of the arm this PULLs the thrust bearing out of the clutch plate.
So although the clutch basically works are cannot really trust it. As if I hit the clutch hard twice its likely to disengage the clutch bearing and leave the clutch engaged.
I wonder should the thrust bearing arm have any kind of spring on it.
Any help is much appreciated as it seems a crying shame to scrap what has been very loyal and dependable family car, ( we are actually sentimentally attached to this car )

[CheapMotor]

I thought I would make the effort and come back and answer my own question in case anyone else googles for it, this issue nearly scrapped my car and caused the clutch mechanism to rip the trust bearing out the clutch plate. And the issue was so simple and cost about 5p to fix. ( but was hard to diagnose ) . When we got the gear box out a second time we noticed that when we tried out the trust bearing on the gear box spine it was sticky, in fact the closer the trust bearing was pushed towards the gear box the tougher it was. We cleaned the sleeve that the trust bearing slides up and down on covered it in copper slip, put the gear box back on, problem gone. Car saved.