How many kilometers should a car run before changing the brake fluid?
3 Answers
The replacement cycle for brake fluid is 2 years or 40,000 kilometers, but it is still necessary to refer to the cycle specified in the user manual. Below is relevant information about brake fluid: 1. The function of brake fluid is to transmit the braking pressure to the brake pistons of the four wheels and push the pistons to press the brake pads and brake discs, thereby achieving the braking effect. 2. Brake fluid also has strong water absorption properties, gradually absorbing moisture from the surrounding air and slowly deteriorating. When brake fluid that has absorbed moisture is subjected to pressure, the moisture vaporizes and produces bubbles, causing the brake to feel spongy, severely affecting braking performance while also corroding the brake lines. 3. As the brake pads wear and the piston calipers reposition, the brake fluid level will gradually decrease. When the fluid level falls below the minimum mark, the brake system warning light on the dashboard will illuminate. At this point, simply topping up the brake fluid to the sufficient level is required.
It's generally recommended to replace brake fluid every 2 years or 40,000 kilometers, but after driving many cars, I've found it really depends on the situation. With my old car that frequently went on long trips, I noticed the brakes felt spongy at around 30,000 kilometers. A check revealed excessive moisture in the fluid, affecting braking performance. Prolonged neglect can corrode brake system components, leading to costlier repairs later. Personally, I think 40,000 kilometers is reasonable for city driving, while highway-heavy usage warrants earlier changes at 30,000-40,000 kilometers. Stay vigilant about your car's condition to save hassle and money. Always manually check the maintenance manual—don't cut corners. Safety is no trivial matter; my last oversight nearly caused an accident, so now I stick to regular maintenance. Ultimately, mileage is just a guideline—adjust flexibly based on time and actual usage.
I heard from the repair shop guy that changing brake fluid more frequently is definitely the right move, generally every 40,000 km is the safest bet. For my own daily commute, changing it around 50,000 km hasn't caused major issues, but the brakes can be more affected during humid seasons—if the car skids on rainy days, it's a real hassle. This stuff absorbs moisture strongly and degrades braking performance, especially causing delayed response during high-speed driving. It's recommended to follow the 40,000 km standard for the first few years of a new car, and after more driving, check the fluid quality every 20,000–30,000 km. Don't skimp to save money—repairing a failed brake system for a few hundred bucks isn't worth it. Usually, check the manual and make it a habit; if you exceed the mileage, don't panic but don't delay either. Regular maintenance puts safety first, and that's what matters most.