What is Shimano Mineral Oil made of?

For cyclists who use hydraulic disc brakes, understanding the type of fluid their brakes use is essential. We will explore Shimano mineral oil, highlighting its characteristics, differences from other brake fluids, and why it is considered the ideal choice for Shimano brakes.

What is Shimano mineral oil?

Shimano mineral oil is a special type of hydraulic fluid that is designed for Shimano disc brakes. It is made of lubricant base oil and some additives that enhance its performance and compatibility with Shimano brake components.

Shimano does not disclose the exact ingredients or formula of its mineral oil, but it claims that it is the only fluid that is compatible with its modern brakes.

How does Shimano mineral oil differ from other brake fluids?

There are two main types of brake fluids that are used for hydraulic disc brakes: mineral oil and DOT fluid.

DOT fluid

It is an automotive brake fluid that meets the specifications of the US Department of Transportation (DOT). There are different grades of DOT fluid, such as DOT 3, DOT 4, and DOT 5.1, that have different boiling points and viscosity.

Mineral oil

It is not regulated by any standards and can vary in quality and composition depending on the manufacturer. Mineral oil is not compatible with DOT fluid, and vice versa. Mixing different types of brake fluids can damage the brake system and compromise its performance and safety.

Related: What is Shimano Parallax?

Advantages of Shimano Mineral Oil over DOT

Shimano mineral oil has some advantages over DOT fluid that make it more suitable for bicycle disc brakes. Here are some of them:

Moisture Resistant

Shimano mineral oil does not absorb moisture from the air, unlike DOT fluid. This means that its boiling point does not change over time and does not require frequent bleeding or replacement. Moisture can lower the boiling point of DOT fluid and cause brake fade or failure in extreme conditions.

Paint and Environment Friendly

Shimano mineral oil does not harm painted finishes, unlike DOT fluid. DOT fluid can strip paint and damage plastic or rubber parts if spilled or leaked. Shimano mineral oil is less corrosive and more environmentally friendly than DOT fluid.

Optimal Compatibility

Shimano mineral oil is compatible with the rubber seals and hoses that are used in Shimano brakes. Shimano brakes have very tight tolerances and require specific parts and tools for servicing. Using a different type of fluid can damage the rubber components and cause leaks or malfunctions.

Read Also: Sram NX vs. Shimano Deore: Compared

Why should you use Shimano mineral oil for your Shimano brakes?

The answer is simple: because Shimano says so. Shimano has been making hydraulic brakes since the 1960s and has extensive experience and expertise in developing brake systems that work best with its own fluid. Shimano tests and optimizes its brakes with its own mineral oil to ensure maximum performance, reliability, and durability.

Maintaining Safety and Warranty

Using a different type of fluid or a third-party mineral oil can void your warranty and compromise your safety. You may not notice any immediate problems, but over time, you may experience reduced braking power, inconsistent lever feel, noise, vibration, or even brake failure.

To avoid these risks, you should always use genuine Shimano mineral oil for your Shimano brakes. You should also follow the recommended service intervals and procedures for bleeding and maintaining your brakes. You can find more information on how to do this on the official Shimano website or consult your local bike shop.

Shimano mineral oil is the lifeblood of your Shimano disc brakes. By using it correctly, you can enjoy smooth, powerful, and reliable braking for years to come.


Shimano mineral oil is a specially formulated hydraulic fluid designed for Shimano disc brakes. It offers advantages such as moisture resistance, paint-friendliness, optimal compatibility with Shimano brake components, and maintaining safety and warranty.

To ensure optimal performance and avoid risks, it is crucial to use genuine Shimano mineral oil and adhere to recommended maintenance procedures. By doing so, cyclists can experience smooth, powerful, and reliable braking for an extended period.

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