Check:
1) for rust buildup around the edge(circumference) of the rotor
2) dor any scratch on rotor surface (both side)
3) check both front and back brake pads on each brake
我也来装一把:检查brake fluid Be careful it's toxic and make sure of not letting any dirt drop into the brake fluid. 换brake fluid要快,如果车里或者瓶子里的brake fluid暴露在空气中15分钟没有拧紧盖子,就毁掉了。
剩下的瓶子里brake fluid最好给别的人用,不要保存。如果是空瓶子,要丢到指定的地方或者给dealer处理。