Brembo master dust cap

[MattD]

Purchased a used track bike with a Brembo 19x20 master cylinder. When moving the lever, the dust cap that surrounds the push rod moves and doesn't stay centered on the area below. It looks like it should attach to something? Or be held in place?

I tried taking some pictures, but they aren't the clearest.

Does it need fixing? Or is that just the way they are?

Thanks.

[Expat]

I can look tomorrow, I think they may have a circlip to hold it in place. If there is a groove just inside the bore then that's what it is for.