How Often to Change Brake Fluid

A critical element in your car's braking system is the hydraulic fluid that's involved. But it's surprising to see that it is also one of the most neglected aspects of your car.

Having a good idea about how often to change brake fluid is essential, as this quite quickly could turn into a life and death situation.

Brake Fluid

But before that, it's necessary to understand why braking fluid possesses such great importance. Most modern cars use a hydraulic braking system, this, in other words, helps apply the brakes to each wheel at the same time and the same force. Avoiding the car from skidding as one wheel locks out while the other keeps spinning.

To achieve that synchronized braking, the braking fluid comes to light. This fluid is the blood of the entire braking system; without it, the system would fail. As you apply the brakes, it pushes the fluid. The fluid, in turn, provides pressure to the braking pads that help bring the vehicle to a stop.

How Often to Change Brake Fluid

Why Is It Necessary to Change the Brake Fluid?

Brake fluid isn't like any other liquid; it's a combination of glycol and several types of nonpetroleum fluids. This means that the fluid has to pass a set of aspects before it can be used in your car. They must have high boiling points, high freezing rates, oxidization resistant, and cannot damage rubber parts.

All these aspects must be present in your braking system to meet federal laws. However, as time passes, these fluids lose their potency. Due to aging, the braking fluids are subject to natural components such as air, moisture, and dirt.

This can turn out to be extremely harmful to your brakes as the compromised fluids have a lower boiling point, a freezing rate that has risen, and increased corrosiveness. All this could lead to a fatal event, so as they say, better safe than sorry.

When Should It Be Replaced?

We've established that braking fluid can go bad, but it's necessary to be able to recognize when correctly replacing it would be appropriate. To understand this, there are a few factors that you must consider.

• Manufacturer Recommendations

Like most, you probably throw that instruction book away even before you leave the dealer parking lot. If this is you, then you'll have some research to go through to find the recommended time for replacing your brake oil.

Even though it's the same mechanism being used in most vehicles, the schedule to replace your brake oil tends to differ from manufacturer to manufacturer.

For example, Chevrolet asks for a change at every 45000miles, Honda and Volkswagen recommend a replacement every three years, whereas Mercedes Benz asks you to change it every 20,000 miles.

We recommend that you listen to your manufacturer as they know the workings of your vehicle better than anyone. Their recommendations are based on extensive testing and research. However, on average, brake oil should be replaced every two years or 24,000 miles up to every 3years or 36,000 miles.

• When It Changes Color

It's essential you check your brake fluid from time to time to check for anything out of the ordinary. Brake fluid comes in a clear transparent color or a slightly amber look. In case there is rust present in the fluid, it will cause a reddish hue in the liquid. If this is true, then the brake oil should be replaced immediately.

• Change in Pedal Feel

Muscle memory is crucial when it comes to driving; it helps you in situations where quick thinking isn't the option. However, this same muscle memory also helps to detect the slightest of disturbances.

When moisture enters your brake oil, it causes the boiling point to fall. This, in turn, might cause the fluid to expand, leading to a change in the feel of the brake pedal. This can also increase the stopping time required. All these are indications to replace or flush out your brake fluid.

• Testing

Even if it's difficult for you to understand whether your brake oil needs flushing out, you can carry out a simple test on your brake oil periodically.

Tests can be conducted right from home using test strips or electronic brake fluid tester kits. This will let you know at what level of moisture the brake fluid should be changed.

Video on How to Change Your Brake Fluid


Brake fluid isn't similar to engine oil, where you have to change it regularly. This makes determining how often to change brake fluid an extra bit difficult. However, it's highly recommended that you follow the above-mentioned factors.

Replacing the fluid might require you to cough out about $100 to your repairmen. But that's better than spending several hundreds of dollars replacing the brake lines, calipers, and other components that might be damaged due to corrosion.


John D. Archer is a mechanical engineer and writer based on the area of automotive accessories at, A resident expert and professional, John is passionate about all things automotive and loves to share his knowledge. He has good experience in all kind of automotive accessories. He has worked as a chief mechanical engineer in some reputed automotive garage firm.

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