How many kilometers does a car need to replace brake fluid?

[OSarah]

Brake fluid should be replaced every 2 years or 40,000 kilometers. The hazards of not replacing brake fluid for a long time are as follows: Corrosion of the braking system: Brake fluid itself is hydrophilic. If not replaced for a long time, the brake fluid will corrode the braking system, posing a significant safety hazard. Causing vapor lock: After absorbing water, the boiling point of brake fluid will decrease, which can easily lead to insufficient braking pressure and affect braking performance. When the temperature rises to the boiling point, the water in the brake fluid will boil and produce a large amount of bubbles. As a result, a large amount of gas will exist in the brake lines, and when the brake pedal is pressed, you will clearly feel that it is very soft, with severely insufficient braking force.

[SanGabriella]

I've been driving for many years and usually change the brake fluid every two years or every 30,000 to 50,000 kilometers. Over time, it absorbs moisture from the air, which lowers its boiling point. If the boiling point drops when you brake at high speeds, the brake system might fail, and that's extremely dangerous. Last time, I waited until 40,000 kilometers to change it, and suddenly the brake pedal felt soft—I almost had an accident and rushed to the repair shop. Don’t just rely on the odometer; consider your driving habits too. For example, since I frequently brake in city traffic jams, I need to change it more often. In humid southern regions, brake fluid absorbs moisture more easily, so I recommend checking the water content annually. Regular maintenance can extend the life of your brakes and save you from costly full-system replacements later. Remember, safety comes first—don’t risk it just to save a little money.

[LaMorgan]

Car enthusiasts, let's talk—brake fluid replacement intervals are typically every two years or around 40,000 kilometers, but I love emphasizing it's the heart of the system! As brake fluid ages and absorbs moisture, its boiling point drops from 300°C to just over 100°C, which can lead to vapor lock in the brake discs during hard braking on hot days. I learned from car forums that if a test pen shows moisture content exceeding 3%, it's time for a change—low cost but crucial for protecting the entire braking system. DIY replacement? I don’t recommend it, as improper handling can introduce air and cause bubble issues. Never ignore the manual’s advice—off-road or high-performance vehicles may need earlier replacements. Pay attention to warning signs like a spongy brake pedal or delayed response. Making this a habit keeps your car running smoother and longer, full of driving joy!

[JuliaMarie]

As an ordinary driver, I didn't understand much at first either. Brake fluid should be changed every two years or 40,000 kilometers. The reason is that the moisture content in the fluid increases, and it can foam under high-temperature braking, losing its effectiveness. In case of emergency failure, it could be a matter of life and death. Now I check it every year and a half using a simple DIY test kit, which costs just a few dozen yuan. Considering driving conditions like frequent long trips in summer, it's better to shorten the interval. It's simple and reassuring to maintain, and prolonging the car's lifespan is something you won't regret.