Brake Fluid: Everything you deserve to Know

Every time you apply the brakes on the car, brake fluid, sometimes referred to as hydraulic fluid, is being used. Since the braking system is one of the essential safety components of a vehicle, it should be properly maintained. The fluid is what allows the brakes to function effectively.

In order to stop the car, the brake fluid transfers the force from the depressed brake pedal into pressure and distributes it to the front and rear brakes. No pressure can be produced to bring the car to a complete stop without braking fluid. If there are any leaks or the fluid has not been changed frequently, there may be problems with the road.

Examine the brake fluid reservoir beneath the hood to see how the braking fluid is holding up. There have to be signs displaying the correct fluid level. It is time to add brake fluid if it is at a lower level than usual.

Check the owner’s manual as it differs for each vehicle to learn the suggested interval for refilling the fluid.


Types of Brake fluid

Brake fluid comes in three major varieties: DOT3, DOT4, and DOT5. The most popular braking fluid is DOT3. It has a lower boiling point and a glycol base. In contrast, DOT4 is more effective than DOT3 since it has a greater boiling point. 

Contrarily, the silicon-based fluid known as DOT5 does not absorb water. Out of the three types of brake fluid, it has the highest boiling point. 

On motor vehicles, it is not frequently utilized.


What are the most typical issues with brake fluid?

Brake fluid concerns historically resulted from moisture leaking into the fluid, however servicing problems with fluid today differ from those of 20–30 years ago. In truth, modern flexible brake hose design methods have mostly solved the problem of brake fluid moisture incursion, therefore moisture in brake fluid today isn’t much of a servicing concern.

Brake fluid can now be reliably tested to identify when it needs to be replaced. This is due to the fact that the most frequent problems are caused by the depleted additive package and high quantities of dissolved copper in modern braking fluids. 

The amount of dissolved copper in brake fluid is a good sign for the additive package in brake fluid. Internal brake system component corrosion and possibly sludge buildup may occur when the additive package of brake fluid is depleted.


What is brake fluid Corrosion?

Brake fluid doesn’t corrode by itself, however internal brake hydraulic components may corrode if the additive package, a component of the brake fluid, is exhausted or disintegrates and leaves insufficient anticorrosive inhibitors in the brake fluid.


How Can I Tell If I Need to Change My Brake Fluid?


Burning smell and loud noises

If your car is emitting any significant burning odors, it should be a red flag. The scent could simply be the result of an intense downhill braking battle, but it could also indicate that your entire fluid supply has been burned and has to be replaced.


ABS Light Illuminate

When the ABS dashboard light comes on, you should check your brake fluid and think about replacing it. If everything seems to be in order, there are a few other causes for your ABS light to be on.

Allow your car to cool off after smelling something, then check your fluid. It’s definitely time to think about replacing your brake fluid and having your brakes serviced if you hear a loud screeching, squealing, or squeaking sound emanating from your brakes.


Ineffective Braking

Your breaks need to be responsive and snappy. Your vehicle’s brakes need to be serviced if this isn’t the case or if you’ve noticed a sudden change in how well they’re working. Warped rotors, low or dirty brake fluid, worn brake pads, and other sorts of system wear and tear can all contribute to an abrupt decline in quality.


Changes to the brake pedal

Your brake fluid is probably low or needs to be replaced if your brake pedal isn’t behaving as it once did. When pressed, your brake pedals may feel spongy, bouncy, mushy, or loose.


Myths About Brake Fluid


Myth 1: It’s never necessary to replace the brake fluid.

When the copper content in braking fluid reaches 200 PPM (parts per million) or higher in current vehicles, it needs to be serviced. By doing this, the brake fluid’s additive package and the security it provides will be renewed.


Myth 2: Changing more than half of the braking fluid in a system is practically impossible.

The Firestone Complete Auto Care brake fluid exchange procedure includes draining the old fluid from the master cylinder, refilling it, and then draining the fluid from all four wheels (done in accordance with the manufacturer’s instructions), which eliminates the majority of the old fluid. 

To confirm that there is no or very little copper left in the system, the fluid is then examined once more using the test strip.


Myth 3: Any kind of car can utilize any kind of braking fluid.

Different automobiles with various brake systems require various fluids. Our professionals will make sure that the right fluid is put in your car in accordance with the manufacturer’s recommendations.


Myth 4: All that is ever required to ensure that fresh fluid is in the system is to simply change the master cylinder fluid.

Simply replacing the master cylinder fluid won’t be adequate to remove enough fluid to allow the new fluid to provide the essential protection made possible by the right additive package.


Myth 5: It’s never necessary to replace the brake fluid.

When the copper content in braking fluid reaches 200 PPM (parts per million) or higher in current vehicles, it needs to be serviced. By doing this, the brake fluid’s additive package and the security it provides will be renewed.



For your safety and the safety of your car, brake fluid is crucial! Additionally, it’s advisable to check that your brake fluid isn’t preventing you from maintaining your safe driving practices.

Don’t take any chances when it comes to your car’s brakes; it’s always better to be safe than sorry. It’s vital to keep in mind that when it comes to your car’s braking system, you want to get your car scheduled as soon as possible for a comprehensive inspection or service.


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