When maintaining the brake system of your vehicle, you need to monitor your brake fluid color regularly. Brake fluid will take some years to go bad when you are using the brake system in the right way.
Both vehicle users and drivers must know the color of brake fluid to help you in knowing exactly when the brake fluid needs to be replaced.
Brake fluid color will differ depending on the type of brake fluid you are using. Some of the things that will make a brake fluid change its color are regular heating, banging rubber brake lines, moisture, and aging.
What Is Brake Fluid?
Brake fluid is a hydraulic fluid. When you press down on the brake pedal, it transfers that force to the calipers or wheel cylinders.
That movement creates pressure in the brake lines, and that’s what moves the pistons. The pistons push the pads or shoes against the rotors or drums to create friction and stop your car. It’s a non-compressible fluid, which is why it’s so effective in the brake system.
Brake fluid also has another important job. It lubricates and protects the parts of your braking system from corrosion.
It’s known as a hygroscopic fluid, which means that it traps moisture molecules so they can’t corrode parts internally like the brake lines and calipers, which could cause an unexpected brake problem down the line.
What does brake fluid do?
Brake fluid is the liquid chemical solution utilized in modern automobile hydraulic braking systems. It helps to stop your car by transferring the pressure from your foot on the brake pedal to the brake pads.
The brake pads then press against the rotors, slowing down or stopping the car. It would take a lot more force and pressure to stop your automobile manually without brake fluid.
Understanding Brake Fluid Colors
The color of brake fluid can indicate its condition. Generally, new brake fluid is clear, amber, bluish, red, or greenish.
However, brown or black brake fluid signifies damage and should be replaced. A brake fluid color chart is essential for car owners to determine if the fluid is in good or bad condition.
Brake fluid, when new and fresh in the system, typically appears as a clear, amber, bluish, red, or greenish color.
This can be observed in the transparent reservoir located in your engine compartment where you add brake fluid. However, it is important to note that brake fluid can also turn brown or black, which is a cause for concern.
Clear
Clear brake fluid, with a hint of yellow or golden, is the ideal color for fresh fluid. It indicates that the fluid is clean and free from contamination.
Amber
Amber brake fluid is another normal color for new brake fluid. If your fluid appears amber, it suggests that the fluid is still in good condition and doesn’t require immediate attention.
Bluish
Bluish brake fluid, similar to the color of windshield washer fluid, is also considered normal for new fluid. This color signifies that the brake fluid contains the necessary additives and is functioning properly.
Red
Red brake fluid is another acceptable color for new fluid. This color indicates that the fluid is of the correct composition and can effectively perform its intended function.
Greenish
Greenish brake fluid, similar to antifreeze, can also be seen in new brake fluid. This color is not a cause for concern and indicates that the fluid is suitable for use in your braking system.
It is essential to closely monitor the color of your brake fluid as it can provide valuable insights into the condition of your braking system.
Different Brake Fluid Types
When replacing a master cylinder or brake pad, you need to purchase a bottle of brake fluid. There are three types of brake oils, which include DOT 3, DOT 4, DOT 5, and DOT 5.1.
These brake fluids have different colors. DOT 3, DOT4, and DOT 5 brake fluids have the same color.
The color will change to black or brown over time. The brake fluid color will change due to regular heating, aging rubber brake lines, moisture, and aging. Let us discuss the different brake fluids for automotive in this brake fluid color guide:
DOT 3
The DOT 3 brake fluid is a poly glycol-based product. It was among the first brake fluids to be developed, but it has lost its popularity over the years due to the introduction of more advanced brake fluids. It has a boiling point of 205°C minimum.
Its wet boiling point is 140°C. This brake fluid will absorb around one to two percent water depending on the operating conditions and climate.
The brake fluid is most suitable for light trucks and domestic cars for normal driving. This brake fluid absorbs moisture from the environment, thus reducing its boiling point.
DOT 3 brake fluid has a clear bluish color when it is new. It is well-compatible with all the other brake fluids apart from DOT 5.
DOT 4
This is another brake fluid based on poly glycol. It has a minimum boiling point of 230 degrees Celsius when dry and a minimum boiling point of 155 degrees Celsius when wet.
The brake fluid is used for higher and medium-sized modern vehicles. It is also ideal for vehicles with ABS systems, high-speed braking systems, towing, and high altitudes.
The brake fluid also grips moisture thus reducing its ERPB (boiling point). The fluid can affect the paint of the vehicle, so you need to handle it with care.
The color of the DOT 4 brake fluid is almost mineral clear with a little composition of yellow. It is compatible with DOT 3 and DOT 5.1.
DOT 5
This is a silicone-based brake fluid. It has a wet boiling point of 180°C and a dry boiling point of 260°C.
It is mostly used on military vehicles and antique and weekend collector vehicles, which sit for a long time. This brake fluid is not compatible with DOT 5.1, DOT 4, and DOT 3.
It does not cause any damage to the paint of your vehicle and does not absorb water. The brake fluid is also compatible with rubber formulations.
The fluid absorbs a lot of air, giving you a poor pedal feeling. It is, therefore, not ideal for racing cars because of its compressibility when faced with high temperatures.
When water gets into the DOT 5 brake fluid, it will cause gassing, freezing, and severe localized corrosion.
This is because water is much heavier and does not mix with silicone fluids, making it unsuitable for ABS. This brake fluid is highly compressible under normal braking formation due to foaming and aeration. This gives you a spongy brake feel.
DOT 5.1
DOT 5.1 brake fluid is also based on poly glycol. It has a minimum dry boiling point of 270°C and a wet boiling point of 190°C. The fluid is ideal for racecars, towing vehicles, and delivery and fleet trucks.
The brake fluid can mix well with DOT 4 and DOT 3. DOT 5 has a higher boiling point than DOT 4 and DOT 3 brake fluids.
This fluid also absorbs moisture from the atmosphere, thus reducing its boiling point. The brake fluid can also cause damage to the paint. DOT 5.1 brake fluid is amber in color.
How To Identify Brake Fluid?
In your vehicle, there are many different fluids being used. It’s important for you to know the difference between engine oil, transmission fluid and brake fluid.
Normally, you can tell the difference based on the color and where it comes from. Here are a few examples of the different colors you may see.
- Brake Fluid: Normally amber or clear, but can be blue-green or red
- Engine Oil: Light brown to black
- Transmission Fluid: Red or brown
- Power Steering Fluid: Red, brown or clear
- Coolant: Orange, green, pink or blue-green
The Importance of Changing Brake Fluid
When it comes to a car’s maintenance schedule, you’ll see brake fluid changes listed in certain intervals.
On average, car manufacturers call for a brake fluid change every three years or 45,000 miles, whichever comes first. You can get your recommended schedule in your owner’s manual.
Here are a few of the most important reasons to stay up to date with brake fluid changes.
- Brake fluid is hydrophilic. Every year it absorbs nearly 3% of its weight, which can cause corrosion and wear on the brake system.
- Brake fluid is also hygroscopic, meaning it draws in air moisture.
- As the brake fluid ages, the boiling temperature decreases, so it doesn’t stand up to the heat the same.
- As the brake fluid ages, it holds pollutants and contaminants that can damage the brake system.
You must also consider the ABS and traction control. These vital safety systems rely on the brakes. If the braking system isn’t working as it should, these two safety features are going to suffer, leaving you at risk.
Furthermore, a regular brake fluid change is going to prevent larger problems from occurring.
If you can keep corrosion out of the brake system, you avoid costly repair bills. In this way, regular maintenance acts as an insurance policy against expensive repair bills.
Not only that but if something interferes with braking ability, you could lose more than just a few dollars.
How Do I Check Brake Fluid?
The master brake fluid reservoir can be found by looking around your vehicle or checking your vehicle’s operating manual.
The reservoir is typically made of a semi-translucent material, letting you catch a glimpse of the brake fluid color and its current level. Thanks to this design, you can check on the brake fluid without opening the cap and letting in moisture-rich air near the brake fluid.
pH Level
Using a pH testing strip can help you find the pH level of your brake fluid, which is kept in check using additive packages.
These additives are essential because a more acidic pH level can lead to the brake lines corroding faster. The ideal range will depend on what brake fluid you have in your vehicle, and any drastic spikes in pH usually mean the additive packages have worn out.
Moisture Content
Most brake fluids can safely have a moisture content of one to two percent. Three percent is serviceable, but very close to being dangerous.
Brake fluid with moisture content over three percent should be flushed. You can check moisture content with an optical refractometer or an electronic brake fluid tester.
Copper
Because the moisture in your brake fluid lines can cause the metal to break down, it releases copper into the brake fluid.
You can use common copper testing strips to check on the amount of copper in your fluid. If it exceeds 200 ppm (parts per million), then it’s time for a flush.
Changes in your brake fluid’s color won’t always spell the need for a flush, but it’ll often be one of the first warning signs.
Other tests will likely be more accurate, and we highly recommend conducting them regularly. If you’re unable to get your hands on these tests though, and your brake fluid has changed color and viscosity, it might be time to replace it.
FAQs.
Q: What Color Is Brake Fluid When It Leaks?
Brake fluid starts from being clear to yellowing and becomes darker with age. You might confuse brake fluid with motor oil, but the brake fluid has a more silky texture compared to oil.
If you see a silky fluid leaking from the vehicle, then it is most likely the brake fluid. Leaking brake fluid is mainly clear or amber when it leaks.
Some of the things that can cause a brake fluid leak are problems in the calipers, worn-out brake pads, loose bleeder valves, leaking in the master cylinder, and a faulty ABS unit.
Q: How Do You Know When Brake Fluid Is Bad?
There are various signs of bad brake fluid. One of them is if the brake pedal starts feeling mushy and soft, making it hard for the car to stop.
This is caused when moisture builds up in the brake fluid, thus causing the fluid to boil under pressure and heat of hard breaking, which causes air to be created in the brake lines.
Another way to know that the brake fluid has gone bad is through its color. Bad brake fluid is brown or black. The color of the brake fluid becomes darker with age. If you notice that it has become dark, then it is time to replace it.
Q: What Happens If Your Brake Fluid Is Dirty?
Dirty brake fluid can change the operation of your brake system. You will feel this from the brake pedal, and it can heat dissipation regularly.
On top of that, having moisture in brake fluids can cause internal corrosion of the master cylinder, calipers, and brake lines.
This will finally cause damage to the brake system. It is, therefore, crucial to keep on checking your brake fluid regularly and change it whenever it starts becoming dark.
Q: Does Brake Fluid Have a Smell?
Brake fluid has a funny fishy smell similar to that of castor oil or fish oil. Having knowledge of how the brake fluid smells can help you know when it is leaking. Brake fluid leaks near the brake pedal, and thus you might notice some fishy smell in your vehicle.
Q: What Happens If the Brake Fluid Is Not Changed?
When you fail to change the brake fluid, it absorbs moisture from the environment. Moisture-laden brake fluid can cause corrosion and rust of the metal components.
This results in rust particles getting to the brake fluid, making it contaminated. Failing to change the brake fluids will affect the operating system of your brake system.
Check the brake fluid regularly for the safety of the braking system. After checking the brake system, ensure you have closed the brake fluid reservoir cap well. Failing to close it well can allow grime, debris, and dirt to get in the braking system.
Conclusion
Most of the brake fluids have a clear, yellowish, and golden color. The color of the fluids darkens as it ages, meaning that it has collected debris and absorbed moisture from the environment.
The number of times you change your brake fluid depends on the type of car and how you use the brake system.
Check the brake fluids regularly and note their colors. Long use of bad brake fluid reduces the performance of your car and may eventually damage the braking system and its components.
If you cannot do it yourself, get a professional mechanic to check the brake fluid color and change it on your behalf to ensure the car’s safety.