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How And When To Perform A Brake Fluid Flush On Your Car

Brake fluid flushes are essential to the overall health of your car’s braking system. Old or dirty brake fluid can lead to problems with your brake calipers, ABS sensors, and other important brake components. In addition, old fluid has a higher moisture content which can lead to a soft or spongy brake pedal. The timing of your brake fluid flushes depends on your specific vehicle, although the recommended timing is usually anywhere from two to four years. If you suspect you might be due for a brake fluid flush, keep reading! We will help you understand when to perform a flush as well as how to do the job yourself. Let’s dive in!

What Is A Brake Fluid Flush?

A brake fluid flush is a process by which old brake fluid is flushed from the system and replaced by new brake fluid. Keeping new fluid in the system is crucial to keeping everything working properly and running smoothly. Some auto repair shops use special tools to flush the fluid from the system, although it can also be performed with a few basic hand tools. At a high level, the process involves removing all the old fluid from the brake fluid reservoir, refilling the reservoir with new brake fluid, and pushing the new fluid into the brake lines as the old fluid exits.

You might be thinking that this process sounds just like a brake fluid change. That’s because it is! There is no real difference between a brake fluid flush and a brake fluid change when both are done properly. A complete brake fluid change should remove all the old fluid from the lines and replace it with new fluid as well. Some people might perform a brake fluid change by simply removing the old fluid from the reservoir and refilling it with fresh fluid. However, bleeding the system to remove all the old fluid is crucial, and that step should always be done as part of a complete fluid change.

How To Flush Brake Fluid

You can have an automotive repair shop perform a brake fluid flush on your vehicle, but you can also do the task yourself. Flushing your brake fluid is not extremely difficult, especially if you have some mechanical knowledge. A partner is helpful but not required if you have the right tools. Here are the steps you should take to perform your own brake fluid flush.

— Remove Old Fluid

You will first need to remove all the old fluid from your brake fluid reservoir, which is usually located on top of the master cylinder. A suction pump or even a turkey baster works well for this task. Suction as much of the old fluid as possible out of the reservoir. You can then use an old rag or paper towel to finish removing the remaining fluid. Wipe out the bottom of the reservoir to remove any dirt or debris that might be in there. Make sure that you are careful not to spill any of the brake fluid onto your vehicle. Brake fluid is highly corrosive, and it will damage your paint almost immediately. If you drip brake fluid anywhere, make sure to thoroughly clean it right away. Once you have completed this step, it’s time to add the new fluid!

— Add New Fluid To System

Next, you will want to refill your brake fluid reservoir with new brake fluid. Your owner’s manual should specify the type of fluid to use. The most common types of fluid are DOT 3 and DOT 4 fluid, but some vehicles might require a special type of synthetic fluid. Always follow your manufacturer’s recommendation when selecting the right type of fluid. Filling your car with the wrong fluid can decrease brake performance or even damage parts of your brake system. Once you have added new fluid up to the fill line of the reservoir, you can move to the final step of the brake fluid replacement job.

— Bleed System & Top It Off

The final step includes flushing all the old fluid from your brake system components, including the brake lines, calipers, ABS system, and anything else that could be holding fluid. As the old fluid is flushed out, the fresh brake fluid from the reservoir will be pulled into the system. This part of the process is where it is nice to have a helper. If you don’t have a helper, then you will need a brake bleeder tool to help you complete the job on your own.

If you have a helper, they will only need to press and release the brake pedal. Start by finding the bleeder screw on the brake caliper farthest from the master cylinder. Usually, this will be at the rear passenger wheel. Attach a hose to the bleeder screw and run the hose into an overflow cup or bucket. Have your helper press the brake pedal and maintain constant pressure on it. Then loosen the bleeder screw and allow the old fluid to flow out of the line. Retighten the bleeder screw before your helper releases the brake pedal. Repeat this process until you see fresh new fluid flowing out of the bleeder screw. Move to the next wheel and repeat until you have performed the bleeding process on all wheels. Keep an eye on the brake fluid level in the reservoir during the bleeding process, and make sure to keep the fluid topped off. A low brake fluid level will pull air into the system, and that would require you to start the bleeding process entirely over again.

If you don’t have a helper, don’t worry! You can still bleed your own brake system, but you will need a brake bleeder tool. Simply locate the bleeder screw and attach the hose from the bleeder tool onto the screw. As you loosen the screw, you will use the bleeder tool to suction the old fluid from the line. After the bleeding process is complete, make sure you top off the fluid level in the reservoir, and you are done! You just performed an important piece of car maintenance on your own!

Symptoms Of Needing A Brake Fluid Flush

So, how do you know when you need a brake fluid flush? There are several signs that you can watch for that may signal the need for new brake fluid. Something as simple as your new brakes squeaking doesn’t usually signal a problem, but some symptoms do point to the need for new fluid. If you notice any of these symptoms, then you should head to a local service center right away.

— Soft Brake Pedal

If your car’s brake pedal feels soft or spongy, it could be due to old brake fluid. Brake fluid is hygroscopic, which means that it absorbs moisture. Over time, your old brake fluid will have a fairly high moisture content because of this. Remember that brake fluid is a hydraulic fluid. This means that it does not compress when placed under pressure. Water, on the other hand, does compress under pressure. So, when moisture gets in your brake fluid, you might notice that your pedal feels soft. This is because the moisture is compressing in the brake system instead of completely putting pressure on the caliper pistons. Moisture in a hydraulic system is not good, so a soft pedal might signal the need for new brake fluid right away.

— Decrease In Braking Performance

Old brake fluid can lead to a decrease in braking performance for a number of reasons. First, as already mentioned, brake fluid is hygroscopic. As it absorbs moisture, the hydraulic braking system performance begins to degrade. You may notice that your stopping power has decreased. Contaminants in the old fluid can also damage ABS sensors and other important safety features of your car’s brakes. While a decrease in performance could signal the need for new brake pads or new brake rotors, it could be something as simple as old fluid causing the problem. While the cost of new brake pads is slightly higher than a fluid flush, you can usually get a brake pad replacement for under $300.

— ABS Light

If you see the brake light on your dash, then you have a clear sign of a problem. The ABS light in your vehicle is frequently caused by old brake fluid. As debris and contaminants in the old fluid are pushed into anti-lock braking system components, they can malfunction. Corrosion can also start to form inside your brake lines and cause debris to enter those sensitive ABS sensors. If this happens, you might also incur the cost of a brake line replacement. A problem with a sensor or any other ABS component will cause the light to illuminate. Not only will you need a brake fluid flush, but you may have to replace an ABS sensor as well to fix the problem.

— Visibly Dirty Brake Fluid

Take a look at the brake fluid in your fluid reservoir. It should look fresh and clean. The fluid itself should be almost clear, although it does have a slightly yellow tint to it. If the fluid looks like coffee, then it’s time for a fluid change or a flush! Your brake fluid should not be dark brown, and it definitely should not have a burned smell to it. Similarly, if you can see any debris particles or dirt in the fluid, then you should change it right away.

— Overheating Brakes

Brakes produce a massive amount of heat during normal operation, but they can also get too hot. This can happen when coming to a long stop or constantly using your brakes, like riding down a mountain road. If you notice the smell of burning rubber, your brakes are probably overheating. Brake fluid has an extremely high boiling point, but it should be replaced immediately if it does boil. Brake fluid that gets too hot no longer functions properly, and you will want to perform a brake fluid flush as soon as possible.

How Often Should I Flush My Brake Fluid?

Thankfully, brake fluid flushes do not need to be performed as frequently as engine oil changes. However, most manufacturers have recommended intervals for a brake fluid flush. For most vehicles, you will need to perform a brake fluid flush every 30,000 to 45,000 miles or every three to four years. Some manufacturers, like Toyota, recommend a flush every two years or 20,000 miles. For optimal performance, you should always refer to your owner’s manual for your manufacturer’s recommendation. As long as you stick to the maintenance schedule that your vehicle manufacturer recommends, then you should have no issues with old fluid causing problems with your brakes. If you have any questions about the proper interval, then you can always contact the service department at your dealership for assistance.

Cost Of A Brake Fluid Flush

A brake fluid flush is not an overly expensive car repair. In most cases, a brake fluid flush should cost you anywhere from $100 to $200. Some high-end vehicles may cost more than that, especially depending on the type of brake fluid they require. Generally, this job only requires about an hour of labor, and the brake fluid needed for the job is not that expensive. You can save some money if you decide to perform the work yourself. In most cases, you can purchase the brake fluid required for the flush for about $20. Remember to make sure and buy the proper fluid that your vehicle needs!

The Bottom Line

Brake fluid flushes are a vital part of car care that many people often overlook. However, old brake fluid can lead to many issues, like a decrease in braking performance or damage to anti-lock braking system components. Flushing the old fluid from your system and replacing it with clean new fluid is not an extremely difficult task, and it will help ensure that your car’s braking system runs smoothly for years to come.

Frequently Asked Questions

Is it really necessary to change brake fluid?

Yes, changing your brake fluid is an important part of car maintenance that should not be overlooked. Keeping fresh fluid in your system is important to the overall health of your car’s braking system. Old fluid can lead to a decrease in stopping distance, and it can damage parts of your system, like ABS sensors and even brake calipers. Performing a brake fluid flush is not that expensive, so you should not ignore this important maintenance item.

How often does your brake fluid need changing?

In most cases, brake fluid only needs changing every three to four years or 30,000 to 45,000 miles. Some manufacturers recommend a more frequent interval of every two years or 20,000 miles. You should consult your owner’s manual for specific recommendations on your vehicle. Always follow the interval specified in your owner’s manual.

What happens if you don’t change brake fluid?

Failure to change the brake fluid in your vehicle can lead to damage to your car’s brake system. Old fluid can also cause a decrease in braking performance and an increase in your vehicle’s stopping distance. This could put you in a dangerous situation if you need to make a sudden stop to avoid an accident. Changing your brake fluid is not extremely difficult or expensive, so you should not ignore this task.

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