The Signs of Low Brake Fluid, Causes, Symptoms and How To

If the car starts showing the signs of low brake fluid, it can cause the brakes to not work at all. There are countless instances that the vehicle brake system saves lives from road-related accidents. Count that one instance when someone suddenly crosses the pedestrian lane when the red light switched to green light. Or that one night you are a bit tired from work that you have to press the pedal when you felt dizzy.  

The Brake Fluid, Hydraulic Brake System 

The purpose of the brake system is to prevent accidents. It is a closed system where its effectiveness depends on the condition of its parts and the hydraulic fluid. The hydraulic fluid must run in the system sealed, shut, and free from any other forms of liquid and contaminants such as grits and air.

Related: how to resent ABS light

What does brake fluid mean and what it does? Brake fluid sometimes referred to as hydraulic fluid, is used to move the parts of a brake system. Brake fluid should reach certain standards to work effectively.

  • It must stand a high temperature.
  • It must be free from contaminants like water, air, and dirt.
  • The system must have good working parts.
  • A constant viscosity in brake fluids will adapt to changes in temperature.
  • Brake fluid must keep a low level of compressibility.
  • The brake fluid is stored in a tank called the master cylinder. When you press the pedal, the piston depresses the liquid in the master cylinder. It forces the fluid to travel along the pipelines or slave cylinders. These slave cylinders are paths that lead to the cylinders located the wheels. The fluid is distributed to the whole system.

    The pressure from the fluid causes the rotor to squeeze with the brake pads. Brake pads come in contact with the wheels to slow it down and eventually stop it from moving.

    To put it simply, pressing the pedal pushes the brake fluid down to the mechanisms of the brake system to apply pressure to the rotor. The rotor, once it made contact with the brake pads, the wheels will stop moving.

    Read Next:

    Low Brake Fluid Symptoms

    Generally, the brake fluid can last as long as the vehicle is working. Given that the entire system seals the fluid, there are no reasons that brake fluids cannot work the way it should be. Here are 5 signs of low brake fluid. 

    1. The ABS or Anti-lock Braking System light turns on.

    It’s an indication that you need to add more brake fluid or completely flush the fluid out and replace it.

    All about tail lights and brake lights not working

    2. The master cylinder shows brake fluid is below the minimum level.

    3. You are having trouble pressing the pedals.

    Pressing the pedal once should be enough to push fluids to make the brake pads work. If you’re pressing it more than once, you are in trouble. Put your vehicle on the side and check the master cylinder.

    4. Annoying noises.

    If you have no idea how will low brake fluid cause noise, think again. Low brake fluid causes squeaking. Low brake fluid noise is an indication that parts like brake pads are damaged. The repetitive applying of force causes damaged parts.

    5. Leaks.

    Leaks are indications that there are damages in the parts of the brake system. The system should be completely sealed. Leaks cause excessive loss of brake fluid which results in more pressure applied when pressing pedals.

    The brake system has to sustain enough level of brake fluid to keep it working. Avoid implications when you’re not driving low with brake fluid. The followings are what happen when the signs start showing.

  • Driving safety risks
  • Less driving focus
  • Brake system failure
  • Decrease in mileage
  • Higher maintenance requirement

  • Causes of Having Low Brake Fluid

    1. The brake system is contaminated.

    The parts have the chance to get contaminated during the replacement of brake system parts. It happens when moisture gets through the brake lines.

    2. The parts are damaged when the brake system has gone under repair.

    Brake systems are often repaired under circumstances. Once you will need to replace the rotor disc, align the wheels, change the brake pads, and replace the cylinders. These types of jobs will seal off the brake system. The chances of acquiring air on the system are high.

    3. Changes in the temperature.

    During changes in temperature, the brake fluid must have a constant viscosity to get it working properly. It is essential for vehicles with traction control, stability control, and anti-lock braking system.

    To Learn The Tips on Bleeding ABS Module Without Scan Tool, Please Click Here

    How Do You Regularly Check the Level of Brake Fluid?

    1. Find the brake fluid level in the master cylinder. It is usually topped with a screw-capped lid made of plastic. Old models have metal lids. 
    2. For vehicles with ABS, pump your brakes 25 to 30 times. Although you will need someone to help you with this one. Check the wheels after to see if there are leaks.
    3. Before pulling off the cap, make sure that it’s free of dirt. Dirt will infiltrate the brake system. 
    4. Check the level of brake fluid from the master cylinder. There’s a measurement indicator that shows if it’s the brake fluid is low.
    5. If you can’t find it yourself, call your service advisor for help and correct diagnosis.

    Things to do if the Brake Fluid Level is Low

    1. Adding brake fluid

    If the brake fluid is low, can I add more?
    Yes. A little amount of brake will work if you cannot pump your brakes in the meantime. Drive the vehicle to mix the new fluid with the old one. Make sure that the brake fluid is the same as the old one!

    2. Flushing the brake fluid out

    Flush the brake fluid out when the brake fluid is contaminated. Replace the brake fluid at once.

    3. Replacing with a new brake fluid

    Make sure the screw cap is clean. Fill it with the new brake fluid. Let it mix through driving.

    Low Viscosity Brake Fluid vs. Regular?

    Different vehicles vary on the brake fluid’s viscosity requirement. You can check the manual or ask your service advisor which best fit for your vehicle model.


    Bring your vehicle to your technician regularly. Regular maintenance saves you from more repairs. Check your brake level and signs of low brake fluid regularly. It pays to prioritize your safety. Lastly, drive safely!


    SIGNS TO NEED MORE BRAKE FLUID - newtonscarcare
    Hydraulic brake -

    Leave a Comment