dear all,

a few weeks ago i noticed a little bit of brake fluid on the top of the brake fluid reservoir. i figured the cap was not seated on all the way (or seated properly). i wiped the fluid and re-seated the brake fluid reservoir cap. i did notice that if i tightened it too much, it would click and i'd have to re-tighten it all over again (stopping right before the click)

today i noticed a little bit of brake fluid on top of the reservoir again. you can see it right around the edge:



the brakes seem totally fine. i had them bleed by a high end independent porsche shop about 9 months ago (~5K miles ago).

any ideas of what this could be? the fluid is right around the 'max' marks. my first step will be replacing the reservoir cap but if anybody has any other suggestions, i'd LOVE to hear them.

thanks.

P.S. - what does the "clean filter cap before removing" mean? why before? how can you clean it before removing? gosh i feel stupid, i suspect the answer will be super simple.
P.P.S. - FWIW, i searched the forum without much luck
P.P.P.S - i do exercise the brakes a lot when driving (withing speed limits of course )