What is the difference between brake fluid t3 and t4?
2 Answers
About the difference between brake fluid t3 and t4 is introduced as follows: 1. The boiling point values of the two brake fluids are different. The working temperature of the brake system is very high, so the boiling point of t4 brake fluid is higher than that of t3. The boiling point of t3 is 205 degrees, while that of t4 is 230 degrees. Because the brake system operates at high temperatures, moisture will gradually accumulate in the brake fluid. High temperatures can turn the moisture into a gaseous state, leading to poor braking performance, so it is necessary to replace the brake fluid regularly. 2. The applicable ranges are different. The applicable range of t3 brake fluid is 90-140km/h, while that of t4 is higher than t3, with an applicable range of 140-180km/h.
In my years of auto repair experience, the differences between T3 and T4 brake fluids mainly lie in their boiling points and compatibility. T3 has a lower boiling point, with a wet boiling point around 140°C, and tends to absorb moisture from the air, which can cause the brake system to boil under continuous use or in high-temperature conditions, resulting in a soft brake pedal and reduced braking efficiency. In contrast, T4 has a higher boiling point, with a wet boiling point around 155°C, and absorbs less moisture, maintaining stable performance even during frequent braking or mountain driving. T4 fluid is compatible with T3 systems, making upgrades simple while also protecting seals from aging. However, T3 is suitable for regular city driving due to its lower cost, while T4 is recommended for high-performance vehicles or those who frequently drive long distances. Regular replacement is crucial—I recommend checking the fluid every two years to ensure low moisture content. Additionally, always refer to the vehicle manual when selecting brake fluid to avoid misuse and potential malfunctions. In short, safety comes first, and the boiling point difference is key.
