When you are maintaining the car, do not forget to replace the car brake oil, because the quality of the brake oil is directly related to the safety of the owner and passengers. Riders can't help but ask, how often is the brake oil replaced? I have a friend, very willful, the car has driven 100,000 kilometers, never replaced the brake oil, but the brake performance remains as new, which may be a special case, but it does reflect that "the replacement of the brake oil is not based on the number of kilometers", but for most car owners, when the mileage reaches about 40,000 kilometers, in order to ensure the safety of driving, everyone begins to change the brake oil, in fact, this does not make any sense, and it is a waste of money. What are the replacement standards for automotive brake fluids? "Automotive Overview" explains in detail for everyone from the perspective of principle!
Introduction to brake fluids
Brake oil according to the raw materials, process, use of different requirements, can be divided into alcohol brake fluid, mineral oil brake fluid, synthetic brake fluid, in order to ensure the stability of the brake system, brake fluid has a low freezing point, high boiling point, not easy to produce air resistance and other characteristics, summer is not easy to boil, winter will not freeze, can be applied to more harsh and complex working conditions. Most of the brake fluids commonly used in mainland China meet the US DOT3 and DOT4 standards.
Why should I replace my car's brake oil?
Now the brake oil has hydrophilicity, after a long time of use, the moisture in the air will penetrate into the inside of the brake oil, we all know that the boiling point of the water is low, if the owner of the car for a long time to step on the brakes, under severe friction and wear conditions, the temperature of the brake oil will exceed 100 ° C in a very short period of time, resulting in the evaporation of the moisture in the brake oil into water vapor, scattered in the brake oil, thereby forming a gas resistance phenomenon, which will undoubtedly increase the braking stroke of the brake pedal, thereby affecting the braking effect of the brake system.
Where does the water in the brake oil come from? Generally from the outside air infiltration, under normal circumstances, the greater the air humidity, the more moisture in the air is easy to invade the brake oil, the shorter the service life of the brake oil, but if the outside air is very dry, the moisture in the air is very small, in this working condition, the service life of the brake oil will be long, which is why some people's brake oil can be used for 100,000 kilometers, while some people's brake oil can only be used for 40,000 kilometers.
Standards and testing methods for brake oil replacement
When the water content in the brake oil reaches what, the car mainly replaces the brake oil? There is a warning line here - 3%, when the moisture content of the brake oil exceeds 3%, the car mainly considers replacing the brake oil, if the water content reaches 4%, the owner must replace the brake oil, in this case, the brake oil is easy to boil and make the vehicle lose its braking effect, especially in the summer.
How do owners measure the moisture content of brake oil? Here you need to use a tool, brake oil test pen, you can buy it online, the price is very cheap, within 50 yuan, the owner in the detection, open the brake oil pot, the brake oil detection pen into the brake oil pot can be.
In summary, when the owner replaces the brake oil, do not take the number of kilometers traveled as the benchmark, nor listen to the maintenance technician, but take the water content in the brake oil as the benchmark for replacement, the water content of 3% is the early warning line, and 4% is the replacement line. Replace the brake oil according to this standard, safe and save money.