How many kilometers should a car drive before changing the brake fluid?

[LePatrick]

It is recommended to change the brake fluid every 40,000 kilometers. The methods to determine whether the brake fluid needs to be replaced are: 1. Open the brake fluid reservoir cap. If the brake fluid appears cloudy or black, it needs to be replaced; 2. Drive the car at a normal speed above 40km/h and then brake hard. If the braking distance is significantly longer, the brake fluid needs to be replaced; 3. If the brakes feel soft or unstable during normal driving, replacement is required. The reasons for changing the brake fluid are: 1. Moisture or impurities in the air can enter through the vent hole of the reservoir, which will lower the boiling point of the brake fluid; 2. During prolonged braking, the brake lines are prone to vapor lock, leading to reduced braking force or brake failure.