How often brake disc change?
How long a brake disc can last depends on how people drive, how often they drive, and how they use the car, but there are three simple criteria to measure:
1, the general brake pads are 30000-40000 km on the need to be replaced, the brake disc to consider replacing when it arrive 70000km，the rear brake disc 80000-100000 km replacement, general 4S shop recommends replacing the brake disc before replace brake pads two times
2, when the limit mark of the brake pad has touched the brake disk, the brake noise will be issued at this time, and the brake disk has been damaged. Normal brake disc surface should be smooth, scratch will appear after wear. But it does not mean that there is a certain scratch on the need to be replaced, in general, after the replacement of a new brake pads, abnormal sound still can not be eliminated, it is recommended to replace the brake disc.
3, most of the brake disc surface will have three small pits, pit depth is generally about 1.5 mm. If both sides of the pits have been worn flat on the surface, then the brake disc thinning more than 3 mm. This 3 mm will make the brake pedal stroke significantly longer, braking force weakened, this time must be replaced brake disc, to prevent any eventuality.