Brake Fluid Color

It’s important to check the brake fluid color occasionally. Brake fluid powers the hydraulic component in the anti-lock braking system (ABS).  Any force applied to the brake pedal is sent to the wheel cylinders or callipers. Because of the pressure that is built up in the brake line, the pistons are able to move.  Vehicles are brought to a halt by the friction created when pistons force the braking pads toward rotors or drums. Why it works so well in the brake system because it is a non-compressible fluid.

An additional crucial function is performed by brake fluid. It prevents rust and corrosion from forming on your braking system’s components and acts as a lubricant. Since it’s a hygroscopic fluid, meaning it absorbs moisture and prevents it from penetrating other parts like the calipers or the braking lines and causing corrosion. 

brake fluid topup

Brake Fluid Color Appearance and Possible Colors

New brake fluid color can be any of several colors, including clear, amber, blue, red, or green. As you top off your brake fluid, you can observe it in the clear reservoir located in your vehicle’s engine bay.

However, dark or even black brake fluid is possible. In a word, no good can come from that. If your brake fluid color is black, you need to get a new bottle. The presence of impurities, such as debris, dirt, or moisture, that have eroded off the component’s inner during usage, is indicated by a darkening of the brake fluid. You can also Bleed brakes by yourself.

Different Types of Brake Fluid

The brake fluid is required when servicing or replacing the brake pad or master cylinder itself. There are four major types of braking fluids currently available on the market marked as DOT 3 brake fluid, DOT 4 brake fluid, DOT 5 brake fluid, or DOT 5.1 brake fluid. It’s interesting that the colors vary across types of braking fluid. 

All grades of DOT brake fluid share the same color, especially DOT 3, DOT 4, and DOT 5. As time passes, the color fades to grey or brown. Heat, wear on the rubber brake lines, humidity, and time all contribute to a gradual darkening of the brake fluid.

DOT 3 Brake Fluid

Poly glycol is the main ingredient in DOT 3 braking fluid. It was one of the earliest braking fluids created, but as more modern brake fluids have become available, its use has declined. Its minimum dry boiling temperature is 205 degrees Celsius while it has a maximum wet boiling point of 140 degrees Celsius.

Depending on the temperature and humidity, this braking fluid can absorb anywhere from 1% to 2% water. Standard driving conditions are best for this brake fluid, which is best used in light vehicles and domestic cars. This brake fluid has a low boiling point because it readily takes moisture from the surrounding air. The official brake fluid color of DOT 3 brake fluid is transparent bluish-clear. This brake fluid works well with all other types of braking fluid.

DOT4 Brake Fluid

DOT4 also uses poly glycol as the base material. The lowest temperature at which it will boil when dry is 230 degrees Celsius while the wet boiling point is 155 degrees Celsius.  Brake fluid is utilized in modern cars of greater and medium size. The same holds true for vehicles that tow or travel at high altitudes, have anti-lock brake systems, or have powerful braking systems. 

In addition to absorbing moisture and decreasing ERPB, brake fluid is an essential safety component (boiling point). You need to be careful with the fluid because it can damage the car’s finish. DOT 4 brake fluid has an almost mineral-clear hue with a trace of yellow. 

DOT 5 Brake Fluid

Unlike DOT 3 and DOT 4, DOT5 brake fluid uses silicone as the base material. It allows the brake fluid to boil at 180 degrees Celsius when wet and 260 degrees Celsius when dry. While it’s widely used on cars owned by people who only drive them on the weekends or for special occasions. DOT 5 brake fluid has no compatibility with other types of brake fluid. 

It doesn’t soak up moisture, so it won’t ruin your car’s finish. Rubber components would also find this fluid more friendly. The fluid’s high air absorption rate results in a spongy pedal feel. It is, therefore, not suited for racing automobiles as it’s too compressible when presented with high temperatures.

There will be significant dynamic corrosion, freezing, or gassing if water or moisture successfully penetrates into this braking fluid. As water is denser and does not combine well with silicone fluids, it is not a good choice for ABS. As a result of foaming and aeration, this brake fluid is extremely compressible even during normal braking conditions. The effect is a soft, spongy braking feeling. 

DOT 5.1 Brake Fluid

DOT 5.1 is another poly glycol braking fluid, but the brake fluid color is amber. It can be heated to a lowest boiling point of 270 degrees Celsius when dry and a maximum boiling temperature of 190 degrees Celsius when wet. 

It is compatible with both DOT3 and DOT4 braking fluids. With a higher boiling point, DOT 5 brake fluid is superior to those two brake fluids. DOT5 brake fluid absorbs atmospheric moisture, lowering its boiling point. However, it may damage your paint when directly exposed. 

Checking Brake Fluid

Now you know that brake fluid starts out a pale yellow as it ages to a brownish color. Seeing brake fluid under your car or near the wheel wells is a sure sign of a leak that requires immediate handling.  To ensure that your vehicle’s brake is well-lubricated, you need also to know how to inspect its fluid and determine its age. This can be achieved by:

First, raise the car’s hood and find the master cylinder; this is where the brake fluid reservoir will be. If you don’t know where this is, look in the manual that came with your vehicle.

Next, make sure the fluid level is between the lowest and highest tic markings by checking it. If the brake fluid level drops dangerously low, you should immediately begin filling it.

Finally, examine the brake fluid color if you have any doubts. It has to be flushed and replaced if it has turned a dark brown color and is oily.