A TOYOTA car has a great difference when braking. In fact, there are other faults in this car. When driving, the steering wheel is heavy on the left and right; the right front half shaft ball cage dustproof sleeve is damaged and oil leaks; the left rear vibration absorber has oil seeping out. Are these problems a failure or an irrelevant failure? I check the side analysis and processing. Fault diagnosis: when the car runs, the brake is stepped down, there will be a "squeaky, squeaky" noise, especially when the emergency brake is more obvious, and the braking should not be abnormal under normal conditions. After the brake sound appeared, I decided that a system or component was faulty.