Which part of a vehicle's brakes are replaced when they wear out?

la puerta
la luz trasera
la pastilla
la rueda

The part of a vehicle´s brakes that has to be replaced when they wear out are the brake´s pad which is called la pastilla in spanish.

so what i did was i used google translate and this is what i got. where do you live? what do you do in your free time? what kind of music, food, sports do you like? what is your favorite color? who is your favorite artist? so what they are doing is asking u questions about urself and u have to respond in spanish or english i bealive. hope this : )