Brake Fluid Change vs Flush – Change It or Flush It?

Although most car owners treat it as such, the brake fluid is not imperishable. Just like the transmission fluid, engine oil, and any other car fluid, it needs a replacement or topping up at some point. 

This leads us to the question, “What is a brake fluid change vs flush?” Well, these two terms refer to the same thing.

A brake fluid flush or change is when the old brake fluid is completely drained and replaced with a new one.

Read on to learn how this procedure is carried out and how it differs from brake fluid flushing. 

What Is a Brake Fluid Change?

This process involves draining all the old fluid and replacing it with new brake fluid. More specifically, a brake fluid replacement follows these steps:

Step 1: Draining old brake fluid

Your mechanic will start by locating the brake master cylinder. This is the part that channels the pressure produced by the brake pedal to the braking system. Once they locate it, they’ll remove the cap and drain most of the old brake fluid. 

Step 2: Clean the reservoir 

The next step involves cleaning the brake fluid reservoir. This is done by wiping the inside of the reservoir with a clean rug. Doing so helps to get rid of any debris or dirt that might contaminate the new brake fluid.   

Step 3: Changing the brake fluid

The next step involves filling the master cylinder with the new, fresh fluid. Usually, the fluid is added up to the “MAX” or “FULL” line. 

If you’re doing this yourself, don’t be quick to put the cap back on. That’s because you need to put enough new fluid in to ensure all of the old fluid has been removed. Chances are, you’ll have to top up the new brake fluid a couple of times. 

You now have a rough idea of how brake fluid changes are done. The question is, are they as important as oil changes? Or, can you skip them? Well, the answer is Yes, they are equally important so you shouldn’t neglect them. 

As you’ll learn later in the article, a brake fluid change reduces corrosion and helps to get rid of deteriorating braking fluid. This, in turn, ensures that your car’s braking system works efficiently. There aren’t any negative consequences of changing the brake fluid. 

What Is a Brake Fluid Flush?

A brake fluid flush is the same as a brake fluid change. Put simply; flushing also refers to draining old fluid and replacing it with new one. It’s only that this process is known by different terms depending on where you come from. 

What Is the Difference Between a Fluid Change and a Fluid Flush?

As already mentioned, a fluid change and a fluid flush mean the same thing. These terms are usually confused with a brake fluid bleed. 

In the bleeding process, the aim is to remove enough brake fluid so as to get rid of any air bubbles present in the brake lines

Too many air bubbles can impede the brake system from working optimally. This explains why the bleeding process is done more regularly than brake fluid flushes. In fact, any time your mechanic changes the brake pads, shoes, or rotors in your vehicle, they’re likely to do a brake bleed as well. 

Also important to note is that the four brakes in a vehicle are bled individually. In other words, each brake is bled one at a time so as to prevent air bubbles from entering the braking system. 

Are Brake Fluid Flushes Necessary?

If you want your brake system to work properly, then brake fluid flushes are mandatory. The main reason for flushing is the fact that it gets rid of deteriorating or old brake fluid.

There are two reasons why the braking fluid deteriorates or goes bad, namely, moisture absorption and contamination. Here’s a more detailed breakdown of the two:

Absorption of moisture

Fun fact: most vehicles use a glycol-based brake fluid which is naturally hygroscopic. What this means is that it easily draws the moisture present in atmospheric air. 

According to experts, the moisture absorption rate of this fluid falls anywhere between 1.5 and 3% and it only gets higher if you live in humid areas. Unfortunately, there’s no foolproof way to prevent this moisture from entering the braking system through parts like the braking hose, joints, and seams. 

When this moisture gets trapped in the brake system, it starts to boil due to the surrounding heat. 

The result is the formation of gas bubbles in the brake lines that compromise the system’s efficiency. Specifically, they cause the brake pedals to have a soft, spongy feeling and corrode metallic parts of the brake system. 


Another reason why brake fluid goes bad is contamination. Here’s the deal, some components of the braking system wear out over time. 

A good example is the rubber element found in the wheel cylinders, calipers, and master cylinders. As it wears out, the tiny bits of rubber that chip off end up in the brake fluid, causing contamination. 

Whether the bad fluid is caused by contamination or moisture absorption, it’s bound to compromise the efficiency of the brake system. This is why a brake flush is necessary. 

What Happens if You Never Flush Brake Fluid?

Without a flush, the moisture that ends up in the brake system will start to build up. The higher the moisture content, the less efficient the braking system will be. Eventually, you’ll experience a total brake failure. 

How Often Should Brake Fluid Be Changed or Flushed?

You should flush the brake fluid in your vehicle once every 2 years or 30,000 miles.

Most vehicle manufacturers include this information in the owner’s manual. So ensure you go through it before deciding on the frequency.

In addition, you should watch out for signs such as:

A soft or springy brake pedal

If your brake pedal feels a little bit springy or loose, it’s likely that the brake fluid needs flushing. The main culprit behind this is air penetrating into the brake lines. This then hinders the fluid from flowing freely, giving the pedal a soft or spongy feel.

Slowed braking performance

Ideally, the braking system should respond swiftly and instantly. If this mechanism is taking too long to respond, consider getting brake services as soon as possible. 

Unresponsive brakes are often the result of worn brake pads and damaged rotors.

However, this can also be caused by an underlying problem such as worn tire treads or bad brake fluid. A car expert will be able to examine each component and pinpoint the exact cause.

Weird noises or smell when braking

If you notice an unusual sound or smell each time you press the brakes, you should get the entire system inspected. This could be happening because the braking fluid is burnt, contaminated or its level is too low. Whatever the cause, be sure to consult a professional.

Cost to Consider 

If you’re looking to replace or flush your braking fluid, expect to spend $90 to $200. The price varies widely because of differences in brake fluid brands and the cost of labor. 


Have you been wondering about the difference between brake fluid change vs flush? Well, the two terms mean the same thing; hence, they can be used interchangeably. 

The brake flushing process involves draining your current brake fluid and replacing it with a new fluid. This should be done every 30,000 miles or 2 years (whichever occurs first) and preferably by a professional mechanic. 


Dean Alvarez, TireForge Head Author

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