very weird and random sound from the front right

[criss]

hi guys, after i put a set of new brake disc and pad for front and rear( DBA slotted and carbotech XP8&AX6),
then i went track day, one or two days later i found that there is some weird noise show up randomly, its like "GRRRRRRR",
like something hard and vibrating very fast, it last around 2-3 sec then it stop, i can feel there is a vibration in the cockpit once it happen.
and one day i have a look in the engine bay, found out the brake master cylinder seem to be leaked a bit of oil, and it melted the black thing behind it( is that call brake booster?)

anyone have any idea what it is??

[JBT]

Does this noise only happen when the brakes are applied?
Does the brake master cylinder have any fluid in it?

...melted the black thing behind it( is that call brake booster?)

Melted it Do you mean it has stripped the paint? Must be a big leak.
Sounds like you need a brake system check/overhaul from a brake and clutch place.

[criss]

umm, funny enough, turns out the noise is from a worn out caliper.......