Well to check for calipers seizing, put your hand on each wheel after a run and one should feel warmer than the other

- presumably the one that's making the noise.

All that should be needed is to regrease the pin etc, not replace.

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As for the play, it really depends how it feels and exactly where it is, I can imagine the side to side

'play' would be slight wear in the rack etc but if its more of a knocking then that's not good.

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Not sure what up and down movement you've done, could be top mounts worn

- put your fingers on the topmount nut, and lever the wheel up and down with a plank of wood or something.

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do you get any knocking when driving?

Assume you've checked your wheel nuts are tight?