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Explanation: Actually, we have a term in English that corresponds exactly to Portuguese 'vitrificada(s)' and it is 'vitrified'. This refers to something becoming "glass-like" due to prolonged heat, pressure and / or friction and that's exactly what has happened to the brake pads in your question. They've become vitrified. Car mechanics and people that work on cars do use and understand this term, it's more specific and correct to say that "the brake pads have become vitrified" rather than simply saying that the pads "have worn out" or "need to be replaced". HTH.