Can You Really Go 2 years Without Changing Brake Fluid?

Modern cars have such advanced systems that allow them to continue running even if there’s an issue. Unfortunately, one of the most neglected parts is the brake fluid.

So what happens if you don’t change the brake fluid? 

Well, the number one effect is a decrease in the car’s braking performance. Brake fluid tends to absorb water over time.

This reduces the hydraulic pressure needed to provide stopping power and causes some of the brake systems’ parts to rust. 

If you don’t change your brake fluid often enough, you risk the entire system failing.

Read on to learn more: 

What Does Brake Fluid Do for a Car?

The brake fluid is responsible for converting force – applied on the brake pedal – into the hydraulic pressure needed to slow down or stop a car.

The entire process takes place through a series of steps. 

Once you step on the brake pedal, the first thing that happens is that this force is amplified by a vacuum booster. The vacuum booster is located right behind the pedal. 

The amplified force causes the master cylinder to kick into action, pushing pressurized brake fluid through the brake lines. The more you press on the pedal, the more pressurized the brake fluid.

This, in turn, accelerates the stopping force

Once the fluid flows through the brake lines, it ends up in the calipers. Each wheel has a brake caliper, and this is the part that houses the pistons and brake pads.

So once the brake fluid reaches this component, it activates the pistons. 

These pistons thrust the brake pads against a rotating rotor.

The action of the brake pads rubbing against the rotor produces enough friction on the wheels, causing them to slow down and ultimately stop. 

Now, the only reason why the brake fluid is able to set the pistons into motion is because it’s in pressurized liquid form; thus, incompressible.

If the heat within the braking system causes this fluid to reach its boiling point, it would turn into gas. And unlike liquid, gas is compressible.

So, it would hinder the fluid’s capability to transmit the hydraulic pressure required for braking power. 

Causes of Brake Fluid Breakdown

There are a lot of reasons why your brake system might lose its performance with time, but the following 3 are the most common.

1. Moisture Absorption

Brake fluid is hygroscopic, meaning it readily absorbs moisture from different sources without changing its volume.

The accumulation of moisture leads to a lower boiling point, which makes it unsuitable for intense braking.

Repeatedly pressing the brake pedal can cause bubbles to start forming in the brake master cylinder and affect the internal pressure transmission.

This phenomenon is called brake fade and potentially has severe repercussions in terms of the overall safety and performance of the vehicle.

Generally, the problem manifests in the form of darkened color, so it’s quite important to ensure that moisture absorption is kept to a minimum and not ignored.

2. High Temperatures

The braking system generates substantial heat during normal operation as the brake pads rely on friction to stop the car.

Over time, this heat can cause the brake fluid to break down chemically, which naturally reduces the effectiveness and performance of your car’s brake system.

Temperature degradation is among the primary causes of brake failures during intercity travel because the temperatures can quickly exceed certain limits during the continuous use of hydraulic brakes.

Some other factors that also increase the temperature of brake fluids and cause the aforementioned issues are frequent acceleration/deceleration, towing heavy loads, and driving on tricky terrain.

All in all, it’s integral to keep an eye on any color changes in the brake fluid if your vehicle is heavily used for long distances or on rocky terrain.

Investigate any red flags and make sure that your front brake lines and fluids are in incredible condition for the best performance.

3. Contamination

This is the final reason. Dust, dirt, and debris can find their way into the brake fluid reservoir and lead to blockages or affect the brake fluid’s ability to function optimally. 

Naturally, that’s bad as it can negatively impact the fluid’s performance under pressure and may put lives at risk as the car won’t stop even after you keep on pressing the brake pedal.

How Long Can I Go Without Changing Brake Fluid?

It’s recommended that you change the brake fluid every couple of years. The specific frequency depends on the type of braking fluid you have, mileage, driving conditions, and manufacturer’s requirements. 

As a general rule of thumb, you should replace/ change your brake fluid every two to three years or every 30,000 miles.

However, you’ll want to check the vehicle owner’s manual as it may provide different recommendations. For instance, some manufacturers provide a mileage-based interval of every 45,000 miles. 

To err on the side of safety, have a professional mechanic inspect your car’s braking system from time to time. This way, they’ll let you know when it needs a change and whether the rest of the brake’s components are in good condition. 

Is It Really Necessary to Change Brake Fluid?

Yes, it’s necessary.

If you’ve been wondering whether a brake fluid change is necessary, the answer is a resounding yes.

To understand why this is so important, let’s look at what happens to this fluid over time. 

What Happens to Brake Fluid over Time?

Brake fluid degrades over time. The friction generated by the braking system causes the fluid to wear down and become thinner; hence, reducing its efficiency.

Furthermore, brake fluid is hygroscopic – a technical term meaning that it readily absorbs moisture from the atmosphere.

With time, it absorbs excessive moisture which subsequently reduces its boiling point. 

The lower the brake fluid’s boiling point, the faster it evaporates when exposed to intense heat. And as we saw earlier, this automatically interferes with its ability to provide the hydraulic pressure required for braking performance. 

Another risk that occurs when brake fluids absorb moisture is corrosion. An excess amount of moisture can corrode the master cylinder, brake lines, calipers, and other components of the brake system. 

Can Brake Fluid Go Bad?

Yes, it can

The brake fluid is housed inside a sealed system to prevent contact with moisture and other impurities. 

But over time, moisture and debris in the surrounding environment can penetrate into the brake lines and other parts. Similarly, some of the system’s components can wear out causing the fluid to interact with impurities and go bad. 

What Happens if You Drive With Bad Brake Fluid?

Driving with bad brake fluid is risky as it reduces your car’s stopping capability. The moisture that has accumulated in the brake fluid will begin to boil. This is because of being exposed to intense heat and pressure from hard braking. 

Once it boils, it vaporizes, sending the resulting air through the brake lines. And since gas is compressible, the brake pedal will go down farther as soon as you step on it. 

Gradually, the pedal will lose its firm texture; further reducing the car’s ability to stop. This can be dangerous if you encounter an emergency situation where you need to stop abruptly.  

How Long Can You Go Without Brake Fluid Flush?

There’s no clear-cut answer to this as it depends on the quality of the old brake fluid.

If the fluid hasn’t absorbed too much moisture, you might be able to get away with it. However, you’ll experience a couple of issues, such as increased stopping distance, or brake lockup. 

A brake lockup means that the wheels continue being dragged on the road’s surface even though they’ve stopped spinning

This happens because the friction inside the brake system has surpassed the friction between the tires and the road, and it’s likely to occur when you drive with bad brake fluid.

Meanwhile, increased stopping distance means that the car takes longer to come to a complete halt

If you don’t change or flush your brake fluid at all – despite experiencing these issues – then you risk total brake failure. This means that the car refuses to stop despite continued efforts of pressing the brake pedals. 

Tell-Tale Signs That Your Brake Fluid Needs Topping Up

man looking underneath the hood of car

Not sure whether the brake fluid reservoir needs a top-up? There are some obvious signs that hint at this issue, namely: 

  • ABS dashboard light – have you noticed the abs system light turns on and remains so for a while? If you have, it’s likely that your brake fluid needs a replacement or topping up.
  • Strange noises and smells – if you notice a strange smell or noise every time you step on the brake pedal, it’s likely that the car has a low brake fluid level. Ensure you get your car checked to avoid further issues.
  • Spongy brake pedal – does the brake pedal feel spongy or bouncy? If it does, you’re likely dealing with a brake fluid leakage. The brake system could be causing the fluid to leak. As a result, there’s less hydraulic pressure causing the pedal to feel soft and bouncy. 
  • Poor braking performance – under normal conditions, the brake system should respond instantly. If you’ve noticed slower or decreased response, it could be that the system needs a top-up of new brake fluid.  

How Often Should Brake Fluid Be Flushed?

Changing the brake fluid is the only way to ensure that your brake remains at peak performance at key moments.

The problem is to know when it should be done!

First thing first, it’s important to be clear that there is no time limit on the brake fluid in your car.

Be it 2 years or 4, the old brake fluid can continue to perform if it maintains its chemical structure and is free from all contaminants.

You can generally tell when you need fresh brake fluid by checking its color.

Significantly darker brake fluid means that it’s no longer suitable or safe for your vehicle and should be immediately changed.

Apart from the color, it’s also a good practice to note down the mileage while changing the brake fluid regularly.

While it’s not necessary, and a qualified mechanic will be able to tell you more, it’s recommended to change the brake fluid every 30,000 to 50,000 miles.

For regular-use cars, this distance is usually covered in 2 years, which further fuels the narrative that brake oil should be changed on a time-based interval.

However, the truth is that it’s got more to do with the distance.

How Much Does It Cost for Brake Fluid Flush?

The cost of a brake fluid flush ranges between $80 and $200.

The price differs significantly depending on whether you’re going for a DIY change or hiring a mechanic to perform the whole process.

Brake fluid prices range from $6 to $39 per quart.

Meanwhile, mechanics charge anything between $150 and $200 per hour. 

Best Practices for Brake Fluid Maintenance

Maintaining control of your brake performance is an easy task if you adhere to a few easy tasks. Here are a few things you can do to change the brake fluid and ensure it doesn’t give up on you.

1. Follow Manufacturer Recommendations

Always adhere to the manufacturer’s guidelines regarding brake fluid replacement.

Consult your vehicle’s owner’s manual to determine the recommended brake fluid change schedule based on your specific make and model.

2. Regular Brake Fluid Inspections

Have a qualified mechanic inspect your vehicle’s brake fluid regularly.

They can assess the condition of the fluid, check for contaminants or moisture buildup, and determine if a replacement or brake system flush is necessary.

3. Quality Brake Fluid

Ensure that your mechanic uses high-quality brake fluid that meets or exceeds the specifications recommended by the vehicle manufacturer.

High-quality brake fluid can resist moisture absorption and maintain stable performance over a variety of conditions.

4. Address Brake Fluid Leaks

If you notice any signs of brake fluid leakage, such as low brake fluid levels or visible, contaminated brake fluid, or puddles under your vehicle.

Then have that issue promptly addressed by a professional mechanic. Brake fluid leaks can compromise the entire braking system and should not be ignored.


If you’ve been wondering what happens if you don’t change the brake fluid, the answer is a decrease in your car’s braking performance.

Failure to change means that any moisture and debris in the fluid continue to build up. 

This then leads to a host of issues, such as internal corrosion of the metal parts and a decrease in the brake fluid’s boiling point. Both of these compromise your car’s stopping power.

To avoid this, get brake fluid changed every 2 to 3 years or 30,000 miles (whichever comes first).


Dean Alvarez, TireForge Head Author

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