Can dot4 replace dot3?
3 Answers
dot4 cannot replace dot3. Different types and brands of brake fluid should not be mixed. For braking systems with special requirements, a specific type of brake fluid should be used. Since the formulations of brake fluids from different brands and types vary, mixing them can lead to a decline in the performance indicators of the brake fluid. The difference between dot4 and dot3 lies in their boiling points: the minimum boiling point of dot4 is 230 degrees Celsius, while that of dot3 is 205 degrees Celsius. Brake fluid, also known as brake oil or hydraulic brake fluid, is made from refined diesel distillates with thickeners and antioxidants added. There are three types of brake fluids: mineral oil-based, alcohol-based, and synthetic.
I've always driven older cars and think DOT4 can replace DOT3, with the key advantage being better compatibility. DOT4 has a higher boiling point, making it more resistant to high temperatures, which helps prevent brake failure during long highway drives in summer. I've mixed them before without issues, but I always check the vehicle manual to ensure compatibility. Using incompatible brake fluid can cause system corrosion, so it's best to flush out the old fluid before adding new fluid. Regular maintenance is crucial—changing brake fluid every two years enhances safety. For older vehicles, it's advisable to consult a professional before upgrading. Overall, DOT4 is more reliable, and upgrading improves brake responsiveness, ensuring safer family trips.
In automotive repair practice, I recommend replacing DOT3 with DOT4. It has a boiling point approximately 30°C higher than DOT3, reducing the risk of brake vapor lock and being compatible with most modern vehicle systems. Customers report more stable braking after replacement, especially in mountainous areas or congested roads. However, always consult the vehicle manual to avoid misuse. Brake fluid deteriorates by absorbing moisture, so ensure the system is dry during replacement. For routine maintenance, inspect every two years. Using DOT4 to enhance performance is a cost-effective choice, and the operation is simple enough for DIY at home.
