Porsche cayenne can't stop on rainy days.

The brakes can't stop on rainy days. There are also weather reasons: slippery roads in rainy days reduce the friction between tires and the ground, which leads to the decline of braking effect. The following are the causes of vehicles: 1. Air intake of brake tubing: Brake oil is the medium transmitted by the brake system. If the tubing enters the air, the brake oil under high pressure will be insufficient. Although there is still braking force, the maximum braking force is obviously weakened. The way to judge whether the brake oil pipe is inflated is to step on the brake pedal several times until the brake becomes hard, and then press and hold the brake pedal. If it is always hard, it is normal; If the pedal sinks slowly, it means that the brake system has been inflated. 2. Brake oil will not be replaced for a long time: If the brake oil is not replaced in time, it will contain too many impurities and moisture, which will affect the transmission of braking force. Therefore, the brake oil must be replaced regularly, and the water content of the brake oil must be checked by the maintenance company.