How Often Should Motor Vehicle Brake Fluid Be Replaced?

[LeAdriel]

Motor vehicle brake fluid is generally replaced every 40,000 to 60,000 kilometers or every three years. If black flocculent matter is found mixed in the brake fluid, it should be replaced promptly. Brake fluid has strong hygroscopicity, and prolonged use can lead to vapor lock, which affects braking performance, necessitating regular replacement. Typically, replacement based on time intervals is sufficient, and exceeding the mileage by 10,000 to 20,000 kilometers is not a major issue. If gasoline, diesel, or engine oil accidentally mixes into a brake system that uses synthetic brake fluid, the incompatibility between the fluids can also reduce braking effectiveness. The working pressure of brake fluid is generally 2MPa, but it can reach as high as 4 to 5MPa. All liquids have incompressible properties. In a sealed container or a pipeline filled with liquid, when pressure is applied to the liquid, it quickly and uniformly transmits the pressure to all parts of the liquid. Hydraulic braking operates based on this principle.

[LaMadelyn]

I recommend changing the brake fluid every two years or approximately every 40,000 kilometers, as it is crucial for the safety of the braking system. Over time, brake fluid gradually absorbs moisture from the air, which lowers its boiling point. Under high temperatures, it can easily boil and create air bubbles, leading to reduced braking power or even failure. I once neglected this and experienced a spongy brake pedal, nearly rear-ending the car in front. Fortunately, I promptly took it to a repair shop for replacement. For frequent city commuting or long-distance highway driving, it's best to check more often—don’t just rely on mileage; consider usage habits and climate conditions as well. During inspections, use specialized tools to measure moisture content—if it exceeds 3%, it’s time for a change. Regular maintenance not only prevents accidents but also extends the lifespan of braking components, ensuring safer and more efficient driving. Don’t take unnecessary risks to save a small amount of money.

[StEden]

I believe brake fluid should be changed every two years or 40,000 kilometers – safety first is the golden rule. When brake fluid absorbs moisture, its boiling point drops, leading to more bubbles under high temperatures, which may cause delayed or failed braking, especially during downhill driving or emergency stops – the risks multiply. Personally, I get mine checked at the garage every year and a half, and change it even sooner with heavy driving. Different driving conditions have a big impact; frequent mountain driving or fully loaded long-distance trips accelerate moisture accumulation. It’s cost-effective too – a fluid change costs just over a hundred bucks, while an accident could lead to massive losses. Get it done during routine maintenance – simple, effective, and never compromise on safety. Remember, a well-maintained braking system means peace of mind for family trips. Don’t let it become a hidden danger.

[LeKate]

I don't drive my car much, so I usually change the brake fluid every two years. Last time I delayed it for a few months and felt the brakes were a bit soft, so I quickly replaced it with new fluid. I heard that brake fluid absorbs moisture, and over time its boiling point decreases, especially in high summer temperatures when brakes can easily fail. I recommend following the maintenance schedule in your vehicle's manual and not being lazy. If you frequently drive in the city, moisture accumulates faster, so it's better to change it earlier. Also, check the lines and hoses to ensure the braking system is reliable. Driving gently and braking slowly can reduce the burden, but replacing the fluid isn't a hassle—safety is more important than convenience.