Menu Close

8 Signs of Low (or Contaminated) Brake Fluid


It is quite a concern if your brake light or ABS light comes ON because it is the number one sign behind having a low brake fluid. If your brake pedal starts feeling spongy or it goes all the way to the floor, stop driving your car and tow it to the nearest mechanic!

The hydraulic braking system will not work properly if the brake fluid is LOW or missing. It needs to build pressure in order to function properly and stop your car.

If there is NO pressure, your car is NOT stopping!

In this case, pressing a brake pedal will NOT activate calipers that push brake pads against rotors and stop your car. This means that your braking will be difficult or impossible.

You really don’t want to get to this point and should have your mechanic check your fluid levels out as soon as you notice any of the signs mentioned below. It is also a good idea to have all your fluids checked and topped off on a regular basis.

If your brake pedal is sinking and goes straight to the floor, the first thing you want to do is look for a brake fluid leak:

The top reasons behind difficult braking are:

  • Low or contaminated brake fluid
  • Air in the brake system
  • Damaged Brake Lines
  • Sticky Brake Calipers
  • Worn out brakes
  • ABS problem

How are you notified of a low brake fluid problem?

  1. Brake or ABS light on your dashboard. Although it does not always mean low brake fluid, it will certainly notify you that you need to perform a brake inspection.
  2. Brake pedal problem. If your brake pedal goes to the floor, or braking feels spongy or mushy, there is a big chance that you have a problem with your brake fluid being low.
  3. Fluid puddles next to wheels. Check under the car for puddles next to wheels and if you have them, it is very possible that your brake fluid is leaking.

What happened to brake fluid? First of all, you may have a leak somewhere, which includes lines, hoses, and master cylinders.

In normal conditions, you should NOT lose your brake fluid and only need to top it off during a regular maintenance schedule. Also, if you have been driving with worn-out brakes for a while, it is possible that your brake fluid is depleted.

Why is my brake hard to press? As time goes on, your brake fluid will become dirty and nasty. Good, clean braking fluid is light golden-brown in color and if you see that it is thick and dark, your whole braking system needs to be flushed.

Once your brake fluid is changed and bled, you should have no problem depressing your pedal. Here are some low brake fluid signs (or symptoms):

Symptoms of a low brake fluid

Here are some warning signs of your brake fluid getting too low:

#1. The brake or ABS light is ON

A light brake with an exclamation mark inside of a circle or ABS light is a good notification that something is wrong with your brake system. This doesn’t necessarily mean that you are low on braking fluid, but if you ARE, it will notify you about it.

#2. Low brake fluid levels

This is a clear sign that your brake fluid is low if you check it visually. If you find out that you do NOT have any brake fluid or it is at an extremely low level. Do NOT drive your vehicle and tow it to the service station.

In this situation, your brakes should be checked as well. If your brake fluid is not significantly low, then you can top it off by following the steps mentioned below.

#3. Brake fluid puddles

Having your brake fluid simply leaked out of your brake system is another reason behind its low levels. Your leak could be either internal or external:

  • External leaks will leave an oil-like residue next to your wheels.
  • Internal leaks are more complicated. If you are clearly losing brake fluid but there are no puddles, you may have an internal leak. In this case, you have to deal with more than just a leak, but a damaged brake booster.

If your leak is external, then the puddles will form next to your wheels. Color would be light golden-brown, with viscosity similar to oil.

#4. Brake pedal failing

If you notice that your brake pedal is not pressing down, as usual, there could be a problem with low brake fluid. In this case, when you press your brakes down, it will feel softer, or even go all the way to the floor without doing any braking.

#5. Noise from the braking system

Due to increased friction, when you press the brakes, unusual noises can alert you that your braking fluid is getting low. Take your car to the mechanic ASAP and have your braking system checked out!

#6. The smell from the braking system

If you notice a burning smell coming from your braking system, this could mean that your brake fluid is overheating due to the low quantity of it. It cannot distribute the heat evenly among the brake pads and therefore starts heating up.

#7. Your new brakes are squealing

If it’s not time to change your brakes yet, but they are squealing and squeaking already, you may have a problem with uneven wear and tear on your brake pads. This is usually caused by not having enough brake fluid and your brake pedal is not being pressed with the same amount of power.

#8. Vehicle vibration

If your vehicle is rumbling and vibrating when you use your brakes, this is another sign of low brake fluid.

How to check your brake fluid

  • Step 1. Locate a brake fluid reservoir, which is generally located in the engine compartment at the driver side of the vehicle (where the brake pedal is).
  • Step 2. Check the level of your fluid. If you have a clear reservoir, then there should be a line on the outside marked “full”. In older vehicles, consult the owners’ manual.
  • Step 3. Check the color and viscosity of your fluid by dipping a screwdriver inside. If your fluid is really thick and dark, it needs to be changed. You can also use a brake fluid test kit (paid link) and wait for the color change of a strip.
  • Step 4. Add brake fluid to the “full” line and do NOT overfill. The brake fluid that is recommended specifically for your vehicle should be used.
  • Step 5. Close the reservoir by tightening the cap.
  • Step 6. Wash your hands! Brake fluid is a toxic solution, so make sure you don’t rub it in your eyes or spill it on the paint job of your car.

** Note. After opening a new bottle and refilling, do NOT keep the used bottle with leftovers. Due to the hygroscopic nature of brake fluid, as time passes by, the liquid will not be in a proper useful condition after the seal is broken.

Here is how you can check the level of your brake fluid:

How to refill your brake fluid

  • Step 1. Locate brake master cylinder reservoir.
  • Step 2. Suction the fluid out with a vacuum pump.
  • Step 3. Refill the reservoir with fresh brake fluid (make sure the type is correct).
  • Step 4. Place drain pan under each wheel, starting from the farthest away from the master cylinder (at the rear wheel). A brake bleeder kit (paid link) could also be used.
  • Step 5. Have somebody depress the pedal as you loosen a bleeder valve. To access bleeder screws you will probably need to jack up your car.
  • Step 6. As fluid slows down (or no air bubbles are visible), close the bleed valve.
  • Step 7. Have your assistant release the brake pedal.
  • Step 8. Add more fresh brake fluid to the reservoir.
  • Step 9. Repeat the process at each wheel as many times as needed.

After all is done, top off the reservoir and put the cap back. Test the brake pedal and now you can drive your vehicle.

** Important! Your brake fluid needs to be compatible with your vehicles and you can typically find this information on the reservoir cap of your brake fluid container or owner’s manual (commonly DOT3 or DOT4).

Final Thoughts

If your brake fluid is leaking (especially internally), this could mean a problem NOT only with worn out or damaged lines and other braking components, but it probably created some other problem inside your vehicle. Low brake fluid could also mean that your brake pads need to be checked and may be replaced.

All fluids (including brake fluid) should be checked as a part of the regular maintenance process by your mechanic. If your brake fluid is dirty or discolored, this could also give you problems with your brakes.

Any time you replace your brakes, your brake system should be flushed out completely, because dirt particles in your brake system could seriously damage the new pads.

You don’t really have to refill the brake fluid yourself! Here are some pros, if the process is too messy for you:

Attention! This article is for informational purposes ONLY and is NOT a replacement for professional advice! ALWAYS consult your local specialist for an appropriate solution to your problem. All statements, prices, contact information, recommendations, and reviews contained herein came from sources that we believe to be reliable, but the accuracy or completeness thereof is not guaranteed. Please contact the service provider for complete details and updates.

Leave a Reply

Your email address will not be published. Required fields are marked *

Hit Counter
wp stats