Setting up later-style clutch pedal with rollover spring

Hi...

Clutch master cylinder on a 200tdi 90 needed replacing. I'm taking the opportunity to also replace the pedal for a later 300tdi-style one with the rollover spring (a present for my left knee). I've never done this before and I'm wondering whether there's any sensible way to set it up before returning the assembled unit to the car. Should there be a certain amount of slack or free-play on the pedal (as per original)? It's hard to imagine how there could be any, when that return spring feels so powerful. Do I measure slack by "eye" rather than "feel", i.e. watching for some movement before the two nuts on the rod on the master cylinder are caught up by the movement of the pedal and start depressing the cylinder?

Any help appreciated.

The spring holds the pedal up against the stop, you adjust the master cylinder locknuts to achieve correct pedal height (about 1cm lower than the brake pedal)

After that you should feel a small amount of free play in the pedal before resistance is felt from the master cylinder.

just get a tdci complete unit od the bay approx. £45 take off and refit job done. Also swap the slave !

Cheers, think I've worked it out. (It was actually the slave that went, so I'm swapping the master, too, and thought I'd do something about the pedal at the same time.) Couldn't work out, at first, where the "free play" was meant to be.