Brake fluid is crucial to the safe operation of your vehicle. This fluid is a type of hydraulic fluid used in hydraulic brake systems in vehicles. It is used to transfer force into pressure, and to amplify braking force. Simply stated, when you apply your foot to the brake pedal, brake fluid transfers this force into pressure to the front and rear brakes and stops the vehicle. It works because liquids are incompressible. A brake fluid flush is a procedure that removes old fluid from your brake system and replaces it with fresh brake fluid.
In this post, we will cover what a brake fluid flush is, how often you will need to do it, and how much it will cost. We will also highlight the how to get a brake fluid flush done.
What Is a Brake Fluid Flush?
A brake fluid flush involves draining out contaminated or old fluid from your brake system and replacing it with clean and fresh brake fluid. Flushing helps maintain the health and effectiveness of your vehicle’s brakes.
But What Does Brake Fluid Do?
Brake fluid amplifies and transmits the force you apply when you press down on the brake pedal.
When you engage the brake pedal, that force activates the brake master cylinder. In turn, the brake master cylinder forces the brake fluid along the brake lines to reach the brakes at each wheel.
If your car uses a disc brake system, a plunger inside the master cylinder pushes pressurized fluid into the brake caliper pistons. These hydraulic pistons then squeeze brake pads against the wheel rotor to create friction. And this frictional force helps stop the car. On the other hand, in a drum brakes assembly, pressurized brake fluid acts on the wheel cylinder that pushes a set of brake shoes against drums to stop your wheels.
Irrespective of whether you use drum brakes or disc brakes, there are two kinds of brake fluid flushes:
- Chemical flush: a decontamination procedure where a chemical like denatured alcohol is used for brake flushing and renewing your brake fluid quality.
- Routine maintenance flush: involves draining out the old or dirty brake fluid entirely and replacing it with clean brake fluid.
Now that you understand what a brake fluid flush is, let us go over why it is so critical for brake performance:
Why A Brake Fluid Flush Is Necessary
Your brake system comprises several working parts.
Many of these parts are linked together using brake lines and hoses, which use brake fluid to transmit and amplify forces. That is why it is essential to ensure that the brake fluid retains its quality and does not hamper the functioning of your other brake parts.
And this is where a brake fluid flush comes in. It helps you:
Maintain the Quality of The Brake Fluid
As brake fluid ages with repeated use, chances are that it will get contaminated with material from various parts of the brake system, like:
- Debris
- Metal
- Rubber
- And more
When this happens, it can limit the pressure transmitting capacity of this hydraulic fluid and reduce your stopping power. As the contamination gets excessive, your hydraulic brake system could go out of service which simply means when you press your brake pedal the car does not stop.
Moreover, the additive package in your brake fluid gets depleted over time.
What is that?
The additive package combines corrosion inhibitors, anti-rust compounds, and pH balancers into the brake fluid stored inside your master cylinder. This prevents the fluid from corroding your car’s parts.
Once the additive package level drops, corrosion can build up in the internal brake system and compromise brake functioning.
Conducting a brake fluid flush replaces the bad brake fluid in the master cylinder reservoir with fresh brake fluid to restore additive package levels, remove contaminants, and ultimately improve brake performance.
Prevent Moisture Build Up
Brake fluids are hygroscopic, meaning they tend to absorb moisture.
As the brake fluid encounters several brake system components, moisture content can be detrimental to their functioning.
Why?
The moisture absorbed by the brake fluid can lead to corrosion of several brake parts (for example, the brake calipers, brake rotors, etc.) since many of them are made of metal. And this corrosion can disrupt the functioning of your braking system.
Performing a brake fluid flush eliminates the moisture-laden fluid by using fresh brake fluid in its place to prevent corrosion and ensure the optimal health of other brake components. If these components are exposed to contaminants from the old brake fluid for prolonged periods, they could get damaged and lead to costly repairs.
Flushing the brake system regularly to add clean brake fluid can protect these crucial components from degradation by keeping moisture and debris at bay.
Brake fluid flushes are helpful, but how do you know when your vehicle needs a brake fluid flush service?
Symptoms That Indicate That You Need a Brake Fluid Flush
Here are some signs that indicate that you might need a brake fluid change:
Leaky Brake Fluid
If you notice a brake fluid leak, you could require an immediate brake fluid flush.
A brake fluid leak reduces the braking force that can be transmitted through the brake line.
To confirm your brake fluid level, you can look at the brake fluid reservoir located in your engine bay. Typically, you will find the brake fluid reservoir near the engine compartment. You can refer to your car owner’s manual to find the exact location.
However, if you do not feel confident about confirming a brake fluid leak on your own, you can reach out to an auto mechanic for help. They can come to your driveway, evaluate the brake fluid level, and carry out a brake fluid flush if needed.
Contaminated Brake Fluid
Clean brake fluid looks somewhat golden, light brown, amber, or clear. If you find that the brake fluid is much darker or dirtier, you might need a brake fluid flush soon enough.
This can happen due to excessive brake fluid aging or contamination from rubber, rust, or other debris that gets clogged in the brake line.
If this is the case, take your car to an auto repair shop or have an auto mechanic come to you to perform a quick brake fluid flush service and get your brake system back in perfect condition.
Brake Pedal Feels Soft
At times, when you are applying brakes, you might feel that your brake pedal is spongy.
If brake fluid absorbs too much moisture, air pockets containing water vapor are created when these fluids get exposed to hot temperatures. And these air pockets reduce the effectiveness of your vehicle’s brakes and lead to a soft feeling brake pedal.
When this happens, your brakes will not respond the way you want them to and can turn into a significant safety hazard.
If you notice a spongy pedal, request a brake system inspection immediately. An experienced mechanic can then flush your vehicle’s brake fluid to remove any moisture present in the brake lines and add moisture-free, fresh fluid.
How Often Do You Need a Brake Fluid Flush?
There is no fixed rule as to how often you will need fluid flushes.
Most professional mechanics would recommend that you perform a brake fluid exchange every 30,000 miles or 2 years. This should help you overcome most of the after-effects of aging and bad brake fluid.
You can also check your vehicle owner’s manual for a more specific estimate on how often you would need a brake flush.
However, your timeline for flushing the vehicle’s brake fluid can get accelerated if you are someone who regularly uses the vehicle’s brakes aggressively, such as in stop-and-go traffic.
How Much Does a Brake Fluid Flush Cost?
For an auto repair shop the costs of performing a brake fluid flush can range between $90 and $200. For the DIY home mechanic it may only cost up to about $20 for a large bottle of brake fluid; and hope that no further repairs are required.
It usually depends on your choice of new brake fluid and the auto repair labor costs in your area. Moreover, it can also depend on the year, model, engine, and make of your vehicle.
What Happens During a Brake Fluid Flush?
For best results, it is recommended that you take your vehicle to an auto repair shop for brake service.
During a brake fluid flush, your mechanic would:
- Locate the brake fluid reservoir.
- Drain out the contaminated and old fluid.
- Clean out any debris left in the braking system.
- Check whether any other brake components like the brake calipers, brake pads, or brake rotorswill need to be replaced.
- Carry out brake fluid replacement with high-quality, fresh fluid.
- Remove any air trapped in the brake lines using a bleeder.
- Verify that the brake system is working correctly.
It only takes an experienced mechanic 15-30 minutes to complete, so you can save yourself some time and stress.
Finally
Brake flushing involves removing all the brake fluid from the system and getting all-new, clean fluid inside. Brake bleeding just means removing enough brake fluid to get air bubbles out of the brake lines. Corrosion and rust can cause structural damage to your braking system, leading to costly repairs. Regular brake fluid service can prevent these deeper system issues from occurring. Remember, brake fluid is what is between your brake pedal and the brakes at all four wheels. Make brake fluid a part of your regular maintenance routine, and replace the brake fluid when necessary to keep you and your passengers safe.
