What is Automotive Brake Fluid?
4 Answers
Automotive brake fluid is a liquid medium used in hydraulic brake systems to transmit braking pressure. Within the braking system, it serves as a force transmission medium. Since liquids are incompressible, the pressure output from the master cylinder is directly transmitted to the wheel cylinders through the brake fluid. Information about brake fluid is as follows: 1. Brake fluid is a liquid medium that transmits braking pressure in hydraulic brake systems. It is used in vehicles equipped with hydraulic brake systems and is an indispensable part of the braking system. 2. It effectively lubricates the moving components of the brake system, extending the service life of the wheel cylinders and rubber cups.
I remember when I first learned to drive, I knew nothing about brake fluid. Later, a mechanic told me it's actually a special liquid used to transmit braking pressure, ensuring that when you press the pedal, the brake pads clamp onto the wheels. It's mainly composed of glycol mixtures, which can withstand high temperatures without evaporating, but it has a drawback—it absorbs moisture. Over time, it becomes like lukewarm water, lowering its boiling point, which can cause failure during high-speed emergency braking. I change it every two years or after driving 40,000 kilometers. When doing it myself, I found the fluid reservoir located on the right side of the engine bay, making it easy to check if the fluid level is within the marked lines. Never use other oils as substitutes, or the braking system could suffer serious issues. Last time, my friend nearly had an accident while driving uphill, all because he was too lazy to change the fluid. Always pay attention to how the brakes feel while driving—if they become soft, head to a repair shop immediately.
Brake fluid is a specialized hydraulic oil used for braking, which converts the force from the driver's pedal into pressure to activate the brake calipers. It must resist high temperatures and moisture absorption, as prolonged neglect can lead to water absorption, lowering the boiling point and potentially causing air bubbles, resulting in stiff or failed brakes. I recommend using DOT4 or DOT5.1 standard fluids for their versatility, with a replacement cycle typically around two years. For DIY checks, open the hood, locate the brake fluid reservoir, and inspect its color—clear and transparent is good, while cloudy indicates danger. Make it a habit to quickly test brake responsiveness before driving; if you notice sluggishness, don’t delay, especially before long trips—ensure the fluid level is adequate. Cost-wise, a replacement only costs a few hundred bucks, far cheaper than repairing the braking system, and it ensures the safety of your family's travels.
As the core of the braking system, I believe brake fluid is a critical component for driving safety. Simply put, it's the intermediary liquid that transmits pressure. It must have a high boiling point and low hygroscopic properties, but over time, absorbed moisture can cause it to heat up and boil, leading to brake softening or even failure. When I drive, I pay attention to the reservoir label to ensure the fluid level is between Max and Min, and if the color turns yellow, it indicates aging. It's recommended to check it annually, especially in areas with heavy rainfall, as high humidity accelerates moisture absorption. Using DOT3 or DOT4 fluid is sufficient—just avoid using the wrong type or mixing them to prevent component corrosion. If the brake pedal feels noticeably soft, get it repaired immediately.
