Why is My Brake Fluid Green?


A change in color brake fluidshows that the fluid has been contaminated. However, the brake fluid comes in different colors, which is used to differentiate the types of brake fluid available. However, you need to change the brake fluid when you have a light yellow brake fluid that turns green or a thicker yellow color. Let’s go in depth to get your answer, why is my brake fluid green?

why is my brake fluid green

Why Is My Brake Fluid Green?

When you realize that you have green brake fluid, it is a sign that you need to change the brake fluid. Brake fluids are essential chemicals that the brake system needs to function correctly. It has to be in good condition to work with the brake, and when it starts showing bad brake fluid color, like green, it has gone bad.

When you see a green fluid in your brake fluid reservoir, it means it has been contaminated. The brake fluid’s chemical component can break down after being used for a long time. When this happens, it reacts to parts of the brake, reservoir, and more, causing it to change color. The copper level increases drastically when the fluid reacts to the brake parts, primarily metal parts.

When the copper level in the fluid is high, it instantly turns green and needs to be changed immediately. Some of the causes of this can also be traced to the parts of the brakes. Some of these parts need to be checked regularly.

In addition, you can have a colored brake fluid if it is exposed to external contamination like moisture. The larger the water content in the fluid, the higher its boiling point, which could change the color of the fluid. It could also cause the brake not to function as it should and also result in overheating. While checking the liquid, maintain safety precautions as brake fluid is harmful to skin.

What Color Should Be Brake Fluid?

Brake fluid is meant to be a transparent liquid with a bit of yellow coloring. As the brake fluid is used, the yellow color becomes more pronounced. When the fluid begins to change color, then it means that it is terrible.

However, not all brake fluid comes in light yellow, depending on the type of brake fluid you use will determine its color. Some brake fluids come in light green, blow, red and more.

There are various types of brake fluid, which may include the following:

1. Dot 3

The brake fluid is made from glycol-based fluids but has a lower boiling point than other brake fluid types. It only lasts for a short time and can break down after 20,000 miles of use. It comes in light green, red, or blue.

2. Dot 4

Dot 4 is also a glycol-based fluid with a better boiling point when compared to dot 3. It can last up to 60,000 miles. Dot 4 brake fluid color is light clear yellow or deep red.

3. Dot 5

This brake fluid type is more advanced than Dot 3 and 4. It is a silicone-based fluid. Dot 5 brake fluid color has a clear purple appearance.

4. Dot 5.1

Dot 5.1 has the highest boiling point of about 500F. It appears as yellow, blue, or, most times, crystal clear. This brake fluid answers the question is brake fluid clear, as it appears crystal clear most times.

How Do You Tell If Your Brake Fluid Is Contaminated?

If you suspect that your brake fluid may be contaminated, it is pretty easy to confirm it through the symptoms that your vehicle will show. Below are some signs that your vehicle will show that its brake fluid is contaminated.

1. Sluggish brake response to the brake pedal

2. The brake or ABS warning light will come on

3. Brake pedal will require more force before the brake response

Also, you can check the brake fluid to confirm if it is contaminated. When brake fluids are contaminated, their color will change. The color becomes thicker and more pronounced when it is contaminated.

You can check if your brake fluid is contaminated by looking into the reservoir. It is located in the master cylinder. Ensure to park your car well and leave for a few minutes for the engine to cool down and the liquids to settle. Open the cap of the reservoir and take a look at the liquid. It is contaminated if it has changed color or has a thicker yellow or blue color.

In addition, observe for other contamination like oil. The oil does not mix well with the brake fluid, so you can see the oil floating on the fluid in reserve.

Dirty Green Brake Fluid You Tube

What To Do If You Find Green Brake Fluid?

The best way to deal with contaminated brake fluid is to drain the fluid by bleeding the brakes. By doing this, you can flush all the bad brake fluid out of the brake system; after that, you can fill it with new fluids.

Before bleeding the brakes, ensure first to suck out all the brake fluid from the reservoir. The reservoir contains about 20% of the fluid, which can contaminate the new fluid if not removed.

Also, consult your vehicle manual to avoid further contaminating the brake system when bleeding the brakes. If you cannot do it yourself, consult a professional to help.

Furthermore, it would be best if you determined the cause of the change in the color of brake fluid. It could be a result of a damaged part of the brake. By doing this, you can avoid contaminating the new fluid you will use.  

Conclusion

Why is my brake fluid green? When you have your brake oil green, it means that the liquid has been contaminated. Once you notice this, you need to drain the fluid out of the brake system by bleeding the brakes. Contaminated fluid will damage your brake and make it highly sluggish, which could be dangerous when driving.

Ensure the brake fluid is changed at its recommended period to avoid problems with the system.

Akindayini Temiloluwa

I am Akindayini Temiloluwa, an automotive expert writer and car enthusiast. I have over three years of experience in the automotive writing niche and have completed over 300 pieces of content from 50 projects. I have vast knowledge and skill in vehicle repairing, all mechanical work, car upgrades and maintenance. My goal as an automotive content writer is to simplify the most challenging concepts for my readers, help them self-diagnose what may be wrong with their vehicles and offer real value for their time.

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