How to Choose The Right Types of Brake Fluid1

How to Choose The Right Types of Brake Fluid?

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The lifeblood of your vehicle’s brake system is brake fluid, a frequently disregarded but crucial component. Your vehicle’s stopping is accomplished by a hydraulic fluid.

By means of a network of brake hoses and lines, brake fluid actually stops your car by transmitting the force of pedal depressing to the brake calipers or drums. The National Highway Traffic Safety Administration of the Department of Transportation sets standards for its performance because it must function flawlessly under extremely demanding circumstances.

Why Is Brake Fluid Used?

The braking process depends heavily on the brake fluid. To translate the force of your foot pressing down on the brake pedal into pressure on your car’s brakes, hydraulic braking systems use a liquid chemical solution.

Braking produces a lot of heat. In the brake hydraulic system, the heat causes moisture to condense. This moisture is absorbed by the brake fluid, preventing boiling and subsequent brake failure. Brake fluid also prevents corrosion and lubricates moving parts.

The ability of brake fluid to maintain fluidity at low temperatures and to withstand boiling at high temperatures must pass testing. It must effectively control brake system corrosion and be compatible with other brake fluids, components, and braking system components.

Are Different Types Of Brake Fluids Compatible With One Another?

A particular kind of fluid is designed to work with specific car braking systems. It is essential that the vehicle use that specific type of fluid for the remainder of its service life. This is significant because the internal brake system parts have been chosen, tested, and designed to work with that specific fluid. DOT 3 and DOT 4 fluids are both glycol-based, but because their chemical make-ups differ, they have different effects on the system. It is crucial to continue using the exact brake fluid that the manufacturer advises in order to guarantee that the system functions as it should.

Understanding The Different Types Of Brake Fluid

Brake fluid is referred to by “DOT” and a number. The Department of Transportation (DOT), a federal agency, is in charge of regulating the requirements for brake fluid in motor vehicles in the United States. For the safety of everyone, these regulations guarantee uniform product quality.

A higher boiling point exists for each number. The most common DOT3 or DOT4 fluids used in American vehicles are amber in color, similar to light beer. They are hygroscopic, which is the technical term, and contain glycol, which allows them to absorb moisture from the atmosphere. The top of your bottle should be tightly screwed on, and you shouldn’t need to open the master cylinder reservoir. For this reason, most master cylinder reservoirs are transparent. Brake fluid’s performance will deteriorate over time as a result of its propensity to absorb moisture and the heat produced during braking. It will turn acidic, encouraging the growth of debris and rust in the system, which can clog valves in an expensive ABS system.


DOT 3 is by far the most widely used. A very long time has passed since it was last used. DOT 3 has a boiling point of 401 degrees Fahrenheit when it is fresh, but when it has completely degraded, it is only 284 degrees. This greatly increases the likelihood that your brake fluid will boil. This process can be sped up by using hard brakes, driving steadily downhill, towing, or racing.

Because DOT 3 is so corrosive, extreme caution should be used. It will take paint off, so clean up should be done right away with soap and water or a straightforward degreaser.

Dot 4

European automakers are the main users of DOT 4, but other automakers are starting to use it more frequently. DOT 4 brake fluid comes in a variety of forms, but compared to DOT 3, it has a higher boiling point. Starting at 446 degrees Fahrenheit, these boiling points are. The acids that can develop from moisture are lessened by additional DOT 4 additives.

It is not advised to mix DOT 3 and DOT 4 even though they can technically be. Since DOT 4 is twice as expensive as DOT 3, most people would see little advantage in switching. Make sure you use the right kind of DOT 4 because there are various varieties.

Some vehicles made in Europe and the United States use DOT 4. In Mercedes and Volvo, DOT 4 Plus is utilized. Some BMW models employ DOT 4 Low Viscosity. DOT 4 Racing typically includes a blue color as well.

Dot 5

The boiling point of DOT 5 brake fluid, which is silicone-based, is a very high 500 degrees Fahrenheit. To distinguish it from DOT 3 and 4’s amber hues, it typically has a purple hue. While it does become foamy and the air bubbles are much harder to bleed out, it does not absorb water as much as brake fluids with a glycol base. Because of this, ABS systems shouldn’t use DOT 5.

DOT 5 costs four times as much as DOT 3 and cannot be combined with any other fluid.

Dot 5.1

With a boiling point similar to DOT 4 racing brake fluids, DOT 5.1 is a glycol-based brake fluid. Colors range from clear to amber typically. Although it can technically be mixed with DOT 3 or 4, it is not advised. Around 14 times as much money goes into DOT 5.1 as DOT 3 does.

How to Choose The Right Types of Brake Fluid

When Should I Change It Out?

The manufacturer typically specifies how frequently brake fluid should be changed, but this can change depending on the fluid type.

99% of the car-park utilizes brake fluid that is glycol based and is highly hygroscopic, which means that they absorb moisture from the atmosphere. Brake hoses’ porosity allows brake fluid, which is hygroscopic, to absorb moisture from the environment. This worsens its state and lowers the boiling point. As a result, brake fluid that has been in a car for at least three years has a much lower boiling point than fresh brake fluid from a bottle that has not been opened. Low boiling points, as previously mentioned, cause a reduced response when braking and, in some cases, the Vapour Lock, where pressing the brake pedal has no effect. Vapour Lock occurs when moisture in the brake system turns to steam when heated significantly, causing “compressibility” of the brake fluid Ideally, brake fluid should be clean and clear. Brake fluid that is dark and cloudy has accumulated impurities and needs to be replaced.

Which Brake Fluid Is Ideal For My Car?

To select the proper DOT-rated fluid for your vehicle, consult the service manual. Brake malfunction could result from using DOT-rated fluid in a different way than what is advised.

90% of the vehicles on the road today are technically compatible with DOT 3, DOT 4, and DOT 4 Low viscosity brake fluids that are glycol-based.

The majority of vehicles that use glycol-based fluid, including the newest models and those equipped with anti-lock braking systems (ABS), can use Brembo DOT 4 brake fluid.

We advise using Brembo DOT 4 LV (Low viscosity) brake fluid in vehicles of the most recent generation that have traction control systems (ESP, ASR, TCS, EBD) or ABS systems for stability. Even at very low temperatures, Brembo DOT 4 LV (Low viscosity) brake fluid maintains uniform viscosity. The fluid must maintain its viscosity and flow smoothly in these electronic systems where it passes through valves with incredibly small passageways in order to transfer pressure precisely and instantly.

Brembo advises using DOT5.1 fluids, which have higher boiling points and can withstand higher braking temperatures, for drivers of high-performance cars. However, because of its unique properties, DOT5.1 fluids require more thorough maintenance than DOT 4 fluids.

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