NuBrakes Blog Brake Fluid Flush: Five Signs You May Need One Image

Brake Fluid Flush: Five Signs You May Need One

A brake fluid flush replaces your old brake fluid with new brake fluid and should be done every 30,000 miles or every 2 years to keep your brakes effective. When you press down on the brake pedal, brake fluid goes from the master cylinder into the brake lines which activate the brake pistons to apply pressure from the pads to the rotor.

When the vehicle uses a disc brake system, that fluid travels to brake caliper pistons. These hydraulic pistons squeeze brake pads against the wheel rotor to create friction and stop the vehicle.

In a drum brake system, pressurized brake fluid forces a set of brake shoes against drums to stop the wheels.

There are two types of brake fluid flushes, regardless of whether the braking system uses drum or disc brakes:

  • Chemical flush: a cleaning operation in which a chemical such as denatured alcohol is used to flush the brakes and restore the condition of brake fluid.
  • Routine maintenance flush: old or dirty brake fluid is completely drained and replaced with clean brake fluid.

How Does the Process Work?

When bringing an automobile to the service shop, the technician will identify the brake fluid reservoir and drain all of the old fluid before replacing it with new brake fluid. To do so, the car will need to be lifted and all four wheels removed to eliminate remove all of the old fluid from the brake valve. Tubing linked to the brake valve on one end empties the flush into a prepared container.

While one technician cracks open the valve, a second technician pumps the brakes and holds down the brake pedal. This process will dump the old brake fluid into the waiting container. The color of the old brake fluid should appear dark, but the new brake fluid should appear yellow depending on the type of brake fluid used.

The "flushing" procedure is repeated until the container indicates that fresh, clean brake fluid is reaching the brakes. Before the wheels are put back on the automobile, this operation will need to be completed on all four brakes. Afterward, a road test should be performed to ensure that the brakes are in good working order.

Although it is possible to change brake fluid at home, a mechanic with a brake-flushing machine can do it faster and more thoroughly. If opting for the do-it-yourself method, use high-quality brake fluid. Also, be aware that exposing brake fluid to the outside air can contaminate brake fluid quickly as it can collect water vapor.

Why is a Brake Fluid Flush Important?

Glycol-based braking fluid is used widely in production vehicles and is "hygroscopic," which means it collects moisture that is always present in the air. Engineers estimate that absorption rates range from 1.5 to 3% in areas with normal atmospheric pressures per year.

That rate can be considerably higher in humid climates. There's no way to prevent moisture from entering the lines through small gaps in braking hoses, seams, joints, and other components, so flushing the braking system with clean brake fluid regularly can safeguard these vital components against deterioration.

Keep in mind that brakes convert energy (forward motion) into friction, which gives off heat. That heat from the brake pads and rotors ultimately reaches the brake fluid in the hoses and pipes. Brake fluid begins to boil at lower and lower temperatures as it absorbs more water. Therefore, a brake fluid flush replaces the old brake fluid in the master cylinder reservoir, restoring additive package levels, removing impurities, and improving brake performance.

Five Signs That You Need a Brake Fluid Flush

Brake fluid is one of those "out of sight, out of mind" automobile components often overlooked until something goes wrong. Keep an eye out for these five symptoms that your brake fluid needs to be flushed:

  • A Soft, Bouncy, or Spongy Brake Pedal

    If the brake pedal feels soft, spongy, loose, or even bounces upon applying pressure, this can be an indicator that brake fluid needs to be replaced. Also, if the pedal must be engaged all the way before the vehicle slows or stops, it's time for a brake fluid change. Spongy brakes are caused when, over time, air enters the gaps in the brake line due to low brake fluid. This can result in a frightening and potentially dangerous experience.

  • ABS Dashboard Light

    The appearance of the ABS dashboard light usually results from a low quantity of brake fluid and indicates that the anti-lock braking system is malfunctioning, which usually prevents the wheels from locking up when braking to prevent skids and lost traction. This should be remedied as soon as possible to prevent accidents.

  • Braking Performance Is Ineffective

    Brake response should be swift and sensitive to ensure safety in an emergency. Anything that impedes a car’s ability to slow down or stop indicates that the brakes need to be serviced. Warped rotors, worn brake pads, or a problem with another brake system component are all possibilities.

    An underlying problem, such as deteriorated tire tread, shocks, or struts, could also be the reason for ineffective braking. Nonetheless, these issues may also indicate the necessity for clean brake fluid.

    A specialist can inspect the brake system and determine the best course of action to restore fully-responsive brake function.

  • Strange Sounds or Odors While Braking

    Strange noises accompanying the pressing of the brake could mean a lack of brake fluid or another problem with the brake system. Scraping or grinding noises are also common causes for alarm.

    Burning odors when braking could indicate that the brake fluid has been burned out. In this case, stop the car at a safe location and allow it to cool down. Seek advice from a professional mechanic and plan a servicing visit at the earliest opportunity. Driving with burned brake fluid can cause more catastrophic problems, like brake failure.

  • Routine Maintenance

    Regardless of any specific incidents, rely on the suggested brake fluid replacement plan which is typically every 30,000 miles or every 2 years, to ensure that there is a reduced opportunity for issues to surface. Keep in mind that driving habits also play a role in routine maintenance frequency. Driving shorter routes with frequent braking may necessitate more frequent brake fluid flushes.

    Any brake fluid information particular to the make and model of a vehicle can be found in the owner's handbook.

Final Thoughts

A brake fluid flush helps preserve brake efficiency and prevent corrosion by replacing old or contaminated brake fluid. As brake system components deteriorate over time, changing the brake fluid regularly can not only make your automobile safer, but will also improve the life of your brake components and save money in the long run.

If you are looking for the most convenient automobile service experience, NuBrakes makes brake repair convenient and affordable for everyone by combining our mobile model with the personal, friendly touch of our certified brake repair technicians.

We believe in delivering more than just brake repair, we believe in providing the very best customer service, customer experience, and company culture for every member of our team. Contact us today to get a free quote from our team.


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