The Signs and Causes of Low Brake Fluid

Last updated on December 16th, 2022 at 12:20 am

Low brake fluid is a common issue that can affect the performance of your vehicle’s brakes. It is important to recognize the signs and understand the causes of low brake fluid in order to properly address and resolve the problem. In this blog, we will discuss the signs and causes of low brake fluid and what you can do to prevent it.

Table of Contents

What is a brake fluid?

Brake fluid is a type of hydraulic fluid that is used in the brake system of a vehicle. It is responsible for transferring the force from the brake pedal to the brake calipers, which in turn apply pressure to the brake pads and rotors to slow down or stop the vehicle. Brake fluid is typically made from a mixture of glycol-based fluids and other chemicals that are designed to be stable and non-compressible, which is important for the proper functioning of the brake system. It is typically stored in a sealed container in the vehicle, and is typically checked and refilled by a mechanic during regular maintenance or service.

HOW DOES BRAKE FLUID WORK?

Brake fluid works by transmitting the force from the brake pedal to the brake calipers through a system of brake lines and hoses. When the brake pedal is pressed, it pushes on a piston in the brake master cylinder, which forces the brake fluid through the brake lines and into the brake calipers. The brake calipers contain pistons that are forced outward by the pressure of the brake fluid, which in turn applies pressure to the brake pads and rotors. This slows down or stops the vehicle by creating friction between the brake pads and rotors.

Brake fluid is important because it is non-compressible, meaning that it maintains its volume and pressure when subjected to force. This is important because it ensures that the force from the brake pedal is transmitted evenly and consistently to the brake calipers, allowing the brakes to function properly. Additionally, brake fluid is designed to be stable and not deteriorate over time, which helps to maintain the performance of the brake system and prevent damage to the brake components.

What Are the Signs of Low Brake Fluid

There are several signs that can indicate low brake fluid levels in a vehicle. Some of the most common signs include:

A soft or spongy feeling in the brake pedal: This can happen because low brake fluid levels can cause air to enter the brake lines, which can make the brake pedal feel less responsive and require more force to stop the vehicle.
The brake warning light comes on: In most vehicles, the brake warning light will come on when there is a problem with the brake system. This can be caused by low brake fluid levels, among other things.
Grinding or squealing noises when braking: Low brake fluid levels can cause damage to the brake components, such as the brake pads and rotors. This can cause grinding or squealing noises when the brakes are applied.
A burning smell when braking: If the brake pads are worn down or damaged due to low brake fluid levels, they can produce a burning smell when the brakes are applied.
The vehicle pulls to one side when braking: If one side of the brake system has low fluid levels, it may not be applying the same amount of pressure as the other side. This can cause the vehicle to pull to one side when the brakes are applied.

If you notice any of these signs, it is important to have the brake system inspected by a mechanic as soon as possible to determine the cause and address any issues.

What Causes Low Brake Fluid Levels

There are several potential causes of low brake fluid levels in a vehicle. Some of the most common include:

Leaks in the brake system: One of the most common causes of low brake fluid levels is a leak in the brake lines or hoses. These can occur due to wear and tear on the brake system, or as a result of damage caused by a collision or other accident.
Faulty brake master cylinder: The brake master cylinder is responsible for transferring brake fluid from the brake pedal to the brake calipers. If it is not working properly, it may not be able to supply the brake calipers with enough brake fluid, leading to low levels.
Incorrect fluid level: In some cases, low brake fluid levels can be the result of an incorrect fluid level when the brake system was initially filled. If the brake fluid was not filled to the proper level, it can lead to low levels over time.
Brake fluid absorption: In some cases, brake fluid can be absorbed by the brake system’s rubber seals and hoses. This can cause the brake fluid level to gradually decrease over time.
Brake fluid boiling: If the brake system becomes too hot, it can cause the brake fluid to boil and turn into a vapor. This can cause the brake fluid level to drop, and can also cause air to enter the brake lines, which can affect the performance of the brakes.

It is important to address any issues with low brake fluid levels as soon as possible in order to prevent damage to the brake system and maintain the performance of the brakes.

How Do I Check My Brake Fluid Level

To check the brake fluid level in your vehicle, you will need to locate the brake fluid reservoir. This is typically located near the brake master cylinder, which is usually found near the back of the engine compartment on the driver’s side of the vehicle.

Once you have located the brake fluid reservoir, you can check the level of the brake fluid in the following way:

Clean off the top of the brake fluid reservoir to remove any dirt or debris.
Check the level of the brake fluid in the reservoir using the markings on the side of the reservoir. The brake fluid level should be between the minimum and maximum markings.
If the brake fluid level is below the minimum marking, you will need to add brake fluid to the reservoir.
To add brake fluid, remove the cap from the reservoir and slowly pour the brake fluid into the reservoir until it reaches the maximum marking. Be careful not to overfill the reservoir, as this can cause problems with the brake system.
Once you have added the brake fluid, replace the cap on the reservoir and check the level again to make sure it is at the correct level.

It is important to use the correct type of brake fluid when adding fluid to the reservoir. Check your vehicle’s owner’s manual or ask a mechanic to determine the correct type of brake fluid to use. Using the wrong type of brake fluid can cause damage to the brake system and affect the performance of the brakes.

How to Bleed Your Brakes

Bleeding the brakes is a process that involves removing air from the brake system. Air can enter the brake system through leaks or if the brake system is not properly sealed, and it can cause problems with the performance of the brakes.

To bleed the brakes, you will need a helper, a box wrench or socket set, a clean cloth, a container to catch the brake fluid, and a brake bleeding kit. You will also need a quart of the correct type of brake fluid.

To begin the bleeding process:

Locate the bleeder valves on the brake calipers or wheel cylinders. These are usually located on the back of the calipers or cylinders, and are usually marked with a “B.”
Have your helper get in the driver’s seat and press the brake pedal all the way to the floor and hold it there.
Using the box wrench or socket set, open the bleeder valve on the brake caliper or wheel cylinder that is farthest from the brake master cylinder.
Allow the brake fluid to flow out of the bleeder valve until it runs clear and free of bubbles. Close the bleeder valve and have your helper release the brake pedal.
Repeat this process for each of the other brake calipers or wheel cylinders, working your way from the caliper or cylinder that is farthest from the brake master cylinder to the one that is closest.
Once you have bled all of the brakes, check the brake fluid level in the brake fluid reservoir and add more brake fluid as needed to bring it to the correct level.

It is important to use the correct type of brake fluid when bleeding the brakes, and to be careful not to allow the brake fluid level in the reservoir to drop too low, as this can cause air to enter the brake system. If you are not comfortable bleeding the brakes yourself, it is best to have a mechanic do it for you.

WHEN YOU DRIVE WITHOUT BRAKE FLUID, WHAT HAPPENS

This can be extremely dangerous, as it can make it difficult or impossible to stop the vehicle in an emergency. It is important to regularly check the level of brake fluid in your vehicle and to refill it as needed to ensure that your brakes are functioning properly.

FAQS

Q: Is it dangerous to drive with low brake fluid?

A: It is dangerous to drive with low brake fluid because it can affect the effectiveness of your brakes. If your brakes are not functioning properly, it can be difficult or impossible to stop the vehicle in an emergency, which can increase the risk of a collision or other accident.

Q: Can brake fluid be low without a leak?

A: Yes, brake fluid can be low without a leak. There are several potential reasons why your brake fluid level might be low even if there is no visible leak in the brake system. Some possible causes include:

Brake pad or shoe wear: As the brake pads or shoes wear down, they can cause the brake fluid level to drop. This is because the brake fluid is used to transfer the force applied to the brake pedal to the brake pads, which in turn apply pressure to the rotors to slow down or stop the vehicle. As the pads wear down, more fluid is needed to transfer the force, which can cause the fluid level to drop.
Evaporation: Brake fluid can evaporate over time, especially if the brake system is not sealed properly. This can cause the fluid level to drop slowly over time.
Incorrect fluid level: The brake fluid level may be low if it was not properly filled when the vehicle was serviced.

Q: What happens if I don’t top up my brake fluid?

A: If you don’t keep an eye on your brake fluid levels, you could end up with a completely empty reservoir. This will cause your brakes to fail, and could be extremely dangerous. It’s important to check your levels regularly, and to top up as needed.

Q: Is there a warning light for low brake fluid?

A: Yes, there is a warning light for low brake fluid. This light usually comes on when the brake fluid level is low or there is a leak in the system.

Q: Where does brake fluid usually leak from?

A: Brake fluid can leak from several areas of the brake system, including:

The brake master cylinder: This is a component that houses the brake fluid reservoir and is responsible for converting the force applied to the brake pedal into hydraulic pressure. If the master cylinder is damaged or has worn seals, it can leak brake fluid.
The brake lines: These are the tubes that carry the brake fluid from the master cylinder to the brake calipers or wheel cylinders. If the brake lines are damaged or have loose fittings, they can leak brake fluid.
The brake calipers or wheel cylinders: These are the components that apply pressure to the brake pads or shoes, causing the vehicle to slow down or stop. If the seals on the calipers or wheel cylinders are damaged or worn, they can leak brake fluid.
The brake hose: This is a flexible tube that connects the brake caliper or wheel cylinder to the brake line. If the brake hose is damaged or has loose fittings, it can leak brake fluid.

CONCLUSION

We hope you have enjoyed our article about signs and causes of low brake fluid. With this information, we hope that you can avoid any issues with low brake fluid and be sure to top it off when it is running low. So what are you waiting for? Visit our website to learn more about cars.