How Many Types of Brake Fluid Are There?

[Jimenez]

There are 3 types of brake fluid: 1. Castor oil-alcohol type: made from refined castor oil and low-carbon alcohol; 2. Synthetic type: composed of ethers, alcohols, esters blended with lubricating, antioxidant, anti-rust, and anti-rubber swelling additives; 3. Mineral oil type: made from refined light diesel fractions with thickeners added. Characteristics of brake fluid: 1. Good viscosity-temperature properties, low freezing point, and excellent fluidity at low temperatures; 2. High boiling point, preventing vapor lock at high temperatures; 3. Minimal quality changes, avoiding corrosion and deterioration of metals and rubber.

[VanCody]

After years of working on cars, I've found that brake fluid mainly comes in four standard types: DOT3, DOT4, DOT5, and DOT5.1. DOT3 is the most basic glycol-based fluid, inexpensive but with a relatively low boiling point. It's fine for city driving but can fail at high speeds because it absorbs moisture easily, causing the boiling point to drop over time. DOT4 offers improved boiling point performance and is widely used in modern vehicles. It has better moisture resistance than DOT3 and strong compatibility. DOT5 is silicone-based, completely non-hygroscopic, making it ideal for humid environments or performance cars, though it's more expensive. When changing to DOT5, the system must be fully flushed to avoid air bubbles from mixing. DOT5.1 is compatible with DOT4 but has an even higher boiling point, providing greater safety for aggressive driving. Brake fluid color ranges from light yellow to dark brown, and it should be replaced when it becomes cloudy. Always consult the vehicle manual for the correct type—mixing different brake fluids can lead to brake system failure. For safety, replace the fluid every two years or 40,000 kilometers.

[SanFernando]

As an ordinary car owner, I learned during car maintenance that there are several types of brake fluid. It mainly depends on the DOT rating: DOT3 is the cheapest and suitable for older cars; DOT4 is commonly used in new cars; DOT5 is silicone-based and used for specific models; DOT5.1 is high-performance but rarely used. My own car uses DOT4, with a replacement cycle of about two years. After absorbing water, the boiling point of the fluid decreases, and in humid conditions, the braking distance may become longer. When changing the fluid, the technician said it's essential to choose the right type and not to mix DOT3 and DOT5, as chemical incompatibility can cause sediment to form and block the lines. A simple maintenance tip is to check the color of the fluid in the reservoir—replace it when it turns from clear to cloudy. Safety comes first, don't skimp on costs; choose the right fluid to keep the braking system running stably.

[OAustin]

Bro, there are several types of brake fluid: DOT3, DOT4, DOT5.1, and DOT5. DOT3 is the oldest with a lower boiling point; DOT4 offers better upgraded performance and is commonly used in most cars; DOT5.1 is compatible with DOT4 but has a higher boiling point; DOT5 is silicone-based and doesn’t absorb water, making it suitable for humid conditions. I recommend DOT4—it’s sufficient and no need to go for the expensive ones. The key point is not to mix different types of fluids, as they can react and affect braking. Regularly check the color or perform a boiling point test to ensure good condition, and have the fluid changed at a professional shop for safety.