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.

[OmarMarie]

I've had my brake fluid changed quite a few times, and I think it's really important. The general recommendation is to change it every two years or every 40,000 to 60,000 kilometers, but it depends on driving conditions and the type of vehicle. Brake fluid tends to absorb moisture, and over time, its boiling point decreases, which can cause it to boil during emergency braking, leading to reduced braking power or complete failure. I've driven in all kinds of road conditions, and in humid areas or during rainy seasons, brake fluid deteriorates faster, so the replacement frequency should be increased. Daily driving habits also play a role—for example, frequent hard braking or driving on mountain roads can cause the fluid to degrade much faster. For safety, don't delay replacements. During every maintenance check, I ask the repair shop to test the moisture content with a testing pen. If it's high, I change it immediately—it’s hassle-free and prevents accidents. The vehicle manual is the most authoritative guide, so it's best to follow the manufacturer's recommendations for maintenance. In short, safe driving starts with these small details. A little investment can ensure big safety.

[OClara]

I place great importance on car maintenance, especially the safety of the braking system. The recommended interval for changing brake fluid is typically every 40,000 to 60,000 kilometers or every two years, as brake fluid absorbs moisture which degrades its performance, posing particular risks during long descents or hot weather. Since I often drive my family around, I've developed a habit of checking the braking system every six months; even if you drive less, it's advisable to replace it within two years to prevent issues from fluid aging. Driving conditions are crucial—in humid cities or on dusty roads, replacement should be more frequent. Always consult a professional technician during maintenance, don't cut corners to save money. Protecting yourself and passengers is the top priority, and this small investment is worthwhile. Timely maintenance avoids potential risks, making travel safer and more worry-free.

[KylieAnn]

Generally, brake fluid should be replaced every two years or 40,000 kilometers. When brake fluid absorbs moisture and deteriorates, its boiling point decreases, leading to soft brakes or failure, which is highly dangerous. Over years of driving, I test the moisture content during every maintenance service and replace it immediately if it's too high. Driving habits such as frequent hard braking can affect the replacement frequency. Safety comes first—don't delay.