Brake Fluid Basics: What It Does, How It Works, and When to Change It?

When you press your pedal, do you ever wonder what happens behind the scenes that brings your car to a complete halt? At the heart of this crucial process lies brake oil, a key in ensuring road safety. But the question arises: How exactly does this brake oil function? When do you need to change it? Will answer these questions in today's article. However, before diving deep into the details make sure to join the 91Wheels WhatsApp community to never miss out on any automotive updates.

What Is Brake Oil? How Does It Work?

Brake oil is a liquid that transmits the force from your brake pedal to the brakes, which slows down your vehicle. So, when you press the brake pedal, the fluid transfers the force to the brake components. The brake oil is incompressible; the whole process relies on it. This incompressible nature helps in precise and immediate force transmission when you press the pedal.

Types Of Brake Oil

• DOT 3: It is the most common brake oil in the market. DOT 3 is a glycol-based oil, which has a dry boiling point of 205 degrees Celsius while the degraded DOT 3 can stand only up to 140-degree Celsius. A lower boiling point will lead to overheating and can hamper your braking.
• DOT 4: It is also a glycol-based brake oil and offers a higher boiling point of 230-degree Celsius than DOT 3. This oil has some additives over the DOT 3 version, which makes it suitable to reduce moisture inside the system.
• DOT 5: This brake oil is slightly more expensive than all. It is a silicone-based oil that can even sustain temperatures up to 260 degrees Celsius. Unlike glycol-based oils, it does not absorb water, but it has different issues like foam formation. Formation of lather (foam) is quite easy on this brake oil but removing it is harder than you think.
• DOT 5.1: This brake oil can with stand the highest temperatures up to 260 degrees celsius. It is made from a mix of borate ester and glycol ether. Despite its high-performance capabilities, it shares some characteristics with DOT 3 and DOT 4, such as absorbing moisture over time.

When You Should Change It?

The frequency of changing the brake oil depends on the vehicle and driving conditions. However, there isn't any specific standard interval to change brake oil. Your vehicle might show signs; you shouldn't miss those. Here are a few:-

• Spongy or Soft brake pedal: If you notice that your brake pedal feels soft, or spongy or you have to push it to the floor to slow down the vehicle, this is a sign you need to change the fluid.
• ABS Warning light: If you see an ABS light in your instrument cluster, it might be a braking issue that you need to check.
• Reduced Braking Performance: If you notice your car is taking a longer distance to stop or reduced response of the brake pedal, it means you need to check with the oil.

How To Top Up Brake Fluid?

Maintaining the correct brake fuel is very important for your car. But the question remains: How to top up the brake fluid? Here's a step-by-step process that you can follow:-

• Ensure your vehicle is parked on a flat surface and the engine is switched off
• Open the bonnet and identify the brake fluid reservoir, typically found at the end of the engine bay
• Check the fluid levels in the reservoir. It usually has the MIN and MAX markings on it to indicate the fuel level
• Check your user manual to check the appropriate fuel type for your car's brake
• Top up the recommended brake fluid using a funnel, and avoid crossing the MAX marking

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