What are the key indicators of brake fluid?

The key indicators of brake fluid are as follows.

1.Dry and wet balance reflux boiling point. The boiling point of dry and wet balance reflux of automobile brake fluid is an important indicator to ensure the effective braking of brake fluid.

When the brake fluid has a low boiling point or a small amount of water in the brake fluid, it is easy to produce bubbles or gases, in this case, when the foot pedals are pedaled, there will be a feeling of stepping on the air or feeling that the brakes are ineffective. To this end, the national standard GB12981-2003 stipulates that the dry boiling point of brake fluid is greater than 205, and the wet boiling point is greater than 140. 2.

High and low temperature kinematic viscosity. A good brake fluid can brake reliably not only in hot areas (above 30), but also in cold areas (below -30). The national standard GB12981-2003 stipulates that the kinematic viscosity of 100 is greater than that of -40

HZY-3 and HZY-4 grades are less than 1500mm2 s; The HZY-5 grade is less than 900 mm2 s. Brake fluid that meets national standards, when the temperature is high, the brake is not soft; When the temperature is low, the braking does not lag.

3.Corrosive to metals. The metals that come into contact with automobile brake fluid include iron, copper, aluminum and alloys.

Once these metals are corroded, brake fluid can easily leak out or corrode the metal parts of the braking system, or become stuck, resulting in brake failure. Therefore, qualified brake fluids contain additives such as preservatives and antioxidants.

4.Effect on rubber. The leather bowl and gasket in the brake cylinder of the braking system are rubber parts, and their materials include EPDM rubber, styrene-butadiene rubber, etc.

Qualified brake fluid has good adaptability to rubber and will not shrink the rubber, and the root diameter of the shrinking rubber bowl will be reduced, and the brake fluid is easy to leak out and the brake fails.

Value. In order to prevent the corrosion or erosion of these materials by brake fluid, the pH value of the brake in use is required to be greater than 7, and the value less than is an important indicator to measure whether the brake fluid is acidic or alkaline, and the pH value is < 7, which is acidic, and the acid corrodes the material of the brake system; The pH > is strong alkaline, which also corrodes the related parts of the braking system. Usually a good brake fluid, the pH value is between to to ensure that the more active aluminum and other metal parts are not corroded.

The characteristics of the brake fluid that are truly qualified have several characteristics: that is, to ensure the flexible transmission of braking force under the conditions of high temperature, severe cold, high speed, damp heat and other working conditions; It is not corrosive to metal and non-metallic materials of the brake system; It can effectively lubricate the moving parts of the brake system and prolong the service life of the brake cylinder and leather bowl. Therefore, it is not only related to the safety of driving that consumers choose qualified brake fluid products, but also is very important to extend the service life of the vehicle's braking system.

Automobile brake fluid is a medium used in the hydraulic system of automobile braking, transmitting pressure, and rotating the brake wheels. The function of automobile brake fluid is to keep braking flexible, effective, reliable and safe driving. To this end, we need to understand the types of automotive brake fluid, and let's talk about it from several aspects.

Generally speaking, brake fluid can be divided into alcohol-type brake fluid, mineral oil brake fluid and synthetic brake fluid according to its different raw materials, process and use requirements, among which synthetic brake fluid has the advantages of low condensation point, high boiling point, not easy to produce gas resistance, anti-corrosion, etc., and is widely used in high-speed, large-load automobiles.

1. Mineral oil brake fluid.

Mineral oil brake fluidMineral oil brake fluid is made of deeply dewaxed refined diesel oil as the base oil, and various additives such as teaching agents, antioxidants, rust inhibitors, and dyes are added. There is no unified quality standard for mineral oil brake fluid, and most of the standards are used by enterprises, usually there are No. 7 and No. 9 mineral oil brake fluid, which is red transparent liquid in appearance, has the characteristics of good low-temperature fluidity, and can be used in the temperature range of -50 150 C, and has higher performance compared with alcohol-type brake fluid, but because it has a swelling effect on natural rubber, special attention should be paid to the rubber products in the braking system before using mineral oil brake fluid, and rubber bowls, hoses, etc. can be replaced with oil-resistant rubber products. so as not to corrode and cause the brakes to fail.

2. Synthetic brake fluid.

Synthetic brake fluidSynthetic brake fluid is usually composed of ethylene glycol vinegar, triethylene glycol vinegar, ethylene glycol dirty, water-soluble polyvinegar, silicone oil, polycool, etc. as solvents and lubricants and additives, with a wide range of working temperatures, good viscosity and temperature, and little corrosive effect on rubber and metal. Among the three types of brake fluid, synthetic brake fluid has the best performance, which is suitable for high-speed, high-power, heavy-duty and frequent braking of automobiles, and is currently a widely used brake fluid.

3. Alcohol brake fluid.

Alcohol-type brake fluidAlcohol-type brake fluid raw materials are prepared from low-carbon alcohols and sesame oil, and China issued the ZBE39004-88 alcohol-based automotive brake fluid industry standard in 1988. There are specific regulations on the quality standards of alcohol-type brake fluids. In the process of its application, the product has good lubricity, easy to obtain raw materials, high temperature intensity, simple process, but poor low temperature performance, low boiling point of equilibrium reflux, easy to produce gas resistance, poor mutual banyan with water, easy oxidation and deterioration during use, can not ensure safe driving, easy to cause traffic accidents, China has been eliminated since May 1990.

There are 3 types of brake fluids, which are:

Ricinol type: blended with refined castor oil and low-carbon alcohol;

Synthetic: made of ether, alcohol and ester mixed with lubrication, anti-oxidation, anti-rust and anti-rubber swelling additives;

Mineral oil type: made by adding a thickener to a refined light diesel oil fraction.

Brake fluid is a liquid medium that transmits braking pressure in a hydraulic braking system and is used in vehicles with hydraulic braking systems. Brake fluid brake system is an indispensable part of braking, it is used as a force transmission coarse medium, because the liquid can not be compressed, so the pressure output from the master cylinder will be directly transmitted to the sub-cylinder through the brake fluid.

The performance requirements for brake fluid are as follows:

1. Good viscosity and temperature, low freezing point, good fluidity at low temperature;

2. High boiling point, no gas resistance at high temperature;

3. The quality changes little during use, and does not cause corrosion and deterioration of metal parts and rubber parts.

The brake fluid should have a high boiling point and low evaporation to reduce the generation of gas resistance.

The brake fluid has good corrosion resistance and has good adaptability to rubber parts. Automobile brake fluid, commonly known as brake oil, is a liquid used to transmit pressure in the hydraulic braking system of the automobile hydraulic braking system and the hydraulic control system of the automobile clutch in order to brake the car or make the clutch separate.

The brake fluid should have good fluidity within the operating temperature range, so that the pressure in the system can rise and fall quickly with the action of the brake pedal, and the rubber bowl can slide smoothly in the brake cylinder. Therefore, the brake fluid is required to maintain the proper viscosity over a wide range of temperatures.

How it works

Automobile brake fluid, also known as brake fluid, is a liquid used to transmit pressure in the attitude system of automobile hydraulic braking system, and its advantages and disadvantages are directly related to the reliability of brakes. The brake fluid is used under high humidity for a long time, so it is required that the brake fluid does not produce thermal decomposition and overlap, which makes the oil viscous, and does not allow the formation of sludge deposits.

There are many rubber seals and bowls in the braking system to keep the braking system completely sealed, so the brake fluid should have good adaptability to the rubber seal to prevent the rubber seals and the leather bowl from expanding and reducing the mechanical strength due to liquid oil. There are many rubber seals and bowls in the braking system to keep the braking system completely sealed, and the brake fluid should have good adaptability to the rubber seal to prevent the rubber seals and the leather bowl from expanding and reducing the mechanical strength due to liquid oil.

Three kinds. They are ricinole type, synthetic, and mineral oil type. 1.

Castor oil - alcohol type: 45%-55% refined castor oil and 55%-45% low-carbon alcohol (ethanol or butanol), which is precipitated to obtain a colorless or light yellow clear and transparent liquid, that is, alcohol-type steam steam steam brake fluid. Castor oil plus ethanol is alcohol type 1, and castor oil plus butanol is alcohol type 3.

The raw materials of alcohol brake fluid are easy to obtain, the synthesis process is simple, and the lubrication of the product is good. The disadvantage is that the boiling point is low and the low temperature performance is unstable. Ethanol vapor appears in No. 1 alcohol above 45, resulting in gas lock-off; At -25, castor oil precipitates into a milky white gel, which increases with the decrease of temperature, clogging the braking system and causing the braking system to fail in severe weighting.

2.Synthetic: It is made of ether, alcohol, ester and other additives, and has the functions of lubrication, anti-oxidation, anti-rust, and anti-rubber expansion.

3.Mineral oil type: made from refined light diesel fuel fractions with thickener chain letter and other additives.

What are the levels of brake fluid? How to choose brake fluid, and what performance indicators should be paid attention to when choosing?

Automobile brake fluid, also known as brake fluid, is a fluid used to transmit pressure in the hydraulic braking system of automobiles.

1. Brake fluid level.

In China, brake fluids are divided into JG0, JG1, JG2, JG3, JG4, JG5 and other grades, of which JG3, JG4 and JG5 correspond to the DOT3, DOT4 and DOT5 levels formulated by the US Federal Motor Vehicle Safety Commission respectively. JG0 brake fluid is recommended for use in severe cold areas; JG1 and JG2 brake fluids are generally used in the hydraulic braking system of ordinary vehicles; JG3 level.

2. Brake fluid performance.

Brake fluid requires suitable high and low temperature viscosity, good lubricity, and excellent compatibility with rubber seals, otherwise it will cause problems in the brake system.

3. Use of brake fluid.

The brake fluid can be used in the vast area of China, and is suitable for the hydraulic braking system of various high-end cars and light, medium and heavy vehicles; JG4 brake fluid is suitable for cars with high brake fluid operating temperature; JG5 is used in vehicles with special requirements for brake fluid. At present, for domestic models, JG3 brake fluid is widely used.

Brake fluid has an important impact on the braking effect of the vehicle, because its advantages and disadvantages are directly related to the reliability of the brake, so the purchase of brake fluid is related to the life safety of riders, and must not be taken lightly. After choosing a suitable brake fluid, the subsequent replacement is also a very important issue.

1. Castor oil-alcohol type: It is made of 45%-55% refined castor oil and 55%-45% low-carbon alcohol (ethanol or butanol), and a colorless or light yellow clear and transparent liquid is obtained through precipitation, that is, alcohol-type automobile brake fluid. Castor oil plus ethanol is alcohol type No. 1, and castor oil plus butanol is alcohol type No. 3.

The raw materials of alcohol-type brake fluid are easy to obtain, the synthesis process is simple, and the product has good lubricity; The disadvantage is that the boiling point is low, and the properties are not stable at low temperatures. Alcohol type 1 appears ethanol vapor above 45 in Jiaochun, resulting in gas resistance; At -25 o'clock, castor oil was precipitated in milky white gelatinous substance, and increased with the decrease of temperature, blocking the braking system, making the braking system heavy and out of order, and it was found in the alcohol liter wax resistant type No. 3 leather bowl test that the color of the brake fluid became slightly darker, butanol slightly dissolved and corroded rubber, and there was also white precipitate at -28.

2. Synthetic type: made of ether, alcohol, ester and other additives mixed with lubrication, anti-oxidation, anti-rust, anti-rubber swelling and other additives.

3. Mineral oil type: made by adding thickeners and other additives to refined light diesel oil fractions.

Hydraulic brake (brake) fluid is a functional fluid used in hydraulic braking systems to transfer pressure to stop wheel rotation. Its braking working pressure is generally 2MPa, and the high can reach 4 5MPa. All liquids are incompressible, and when the liquid is under pressure in a sealed container or in a line filled with liquid, the pressure is transmitted quickly and evenly to all parts of the liquid.

Hydraulic brakes work using this principle.