What is Brake Fluid and How Does it Work?

If you’ve ever wondered what makes the brakes in your car work, there are a lot of factors at play. Not only are there multiple parts that make up your car’s brake system, but some of the brake components require lubrication and pressurization to work. That is why your car needs brake fluid.

Brake fluid is the fluid in your car that creates and transports pressure to your car’s brakes. When you press down on your brake pedal, pressure is created within the brake lines. Your brake lines attach to your brake calipers, which is where the braking actually happens. The calibers use the pressure to clamp down on the wheels and force the car to slow down.

Without brake fluid, there would be no way for your car to transfer pressure to your car’s brakes. The brake fluid is necessary for the brake pedal to communicate with the actual brakes. The brake line uses hydraulic pressure from the brake fluid to create this braking phenomenon.

How to Check Brake Fluid

If you’re concerned that you might have a brake fluid leak, it’s smart to look further into the matter. Leaking brake fluid symptoms include squeaky brakes, difficulty braking, or fluid puddling under your car. Of course if you can push your brake pedal to the ground or your car simply won’t brake, there may be a greater problem.

To check your brake fluid levels, you’ll first need to pop the hood of your car. Next you’ll need to locate your brake fluid reservoir. This is the tank that holds your car’s brake fluid.

The brake fluid reservoir can usually be found on the driver side of the engine bay. Look out for the brake fluid reservoir cap which will have some important information on it. Just remove the cap and see if your brake fluid meets the required level shown by the reservoir tank.

If your brake fluid levels are low, then you may need to add more. Brake fluid is circulated from the reservoir tank to the brake calipers, but unused fluid is circulated back into the reservoir.

Over time, the brake fluid begins to break down and get dirtied. By passing through different hoses and tanks, your brake fluid starts to get dirty. Dirt, rust, and metallic particles cause the brake fluid to turn a darker color and be less effective.

Types of Brake Fluid

Depending on the make and model of your car, there may be recommended brake fluids for you to use.

For beginners, there are generally two different types of brake fluid – Glycol ether brake fluid and Silicone based brake fluid. If you’re wondering what color is brake fluid, it is almost always a clear-yellow color. Old or bad brake fluid will be a dark brown and almost resemble oil.

Glycol ether brake fluid is also referred to as synthetic brake fluid. This is the most common type of brake fluid used today. It is used in a majority of cars on the road. These fluids are often sold as DOT 3 brake fluid. They are composed of polyalkelyne glycol ether as well as other glycol that are essentially a form of antifreeze.

Other forms of synthetic brake fluid are DOT 4 brake fluid and DOT 5.1 brake fluid. These fluids contain borate which increases the boiling point for greater strength in the heated engine bay.

Synthetic brake fluids, or glycol brake fluids, are known to absorb water over time. This weakens the brake fluid and the water can make its way into different components of your brake system. If this happens, your brake line will start to deteriorate.

Silicone brake fluid differs from synthetic or glycol brake fluids by not being absorbent. The silicone base keeps moisture from being absorbed into the brake fluid which keeps your brake lines healthier. Silicone brake fluids can compress under high temperatures which can cause your brake line to be less effective.

How to Flush Brake Fluid

If you wondering how to flush brake fluid reservoir, it is actually a quick and easy task. All you have to is pop the cap off the master cylinder of your brake fluid reservoir. Next, insert a turkey baster or another small pump and extract the old brake fluid.

The cost to flush brake fluid is essentially $0 because it’s something you can do yourself with tools at home.

How to Replace Brake Fluid

Once you’ve flushed the old brake fluid out of your master cylinder, you are ready to replace the brake fluid. You will need to buy replacement brake fluid that best suits your car, so make sure to search for what brake fluid should I use before pouring anything into your car. Your brake fluid reservoir cap will also tell you which brake fluid you need to use.

Once you have the proper brake fluid, all you need to do is begin pouring it into the brake fluid reservoir. You can stop once the fluid level reaches the recommended level as shown on the cap or reservoir itself.