How Often Should I Change My Brake Fluid?

Between all of the other maintenance items to keep track of, less thought-about services like brake fluid flushes can be pushed to the back burner. Despite this, brake fluid is one of the most important fluids and maintenance items on your vehicle, especially for safety. 

While it’s understandable most people focus on the life of their rotors and pads, the fluid plays just as large a role in stopping your vehicle and needs to be treated with that importance during servicing. In this article, we’ll go over the job of brake fluid in your system, the symptoms of old brake fluid, the cost of a flush, and how frequently you should have yours changed. 

What is Brake Fluid?

Ballista, CC BY-SA 3.0 http://creativecommons.org/licenses/by-sa/3.0/, via Wikimedia Commons

Like power steering fluid, brake fluid is hydraulic, meaning it’s used to amplify and transfer force from one point to another. In this case, it’s the brake pedal transferring and amplifying force to the pads that are pushed against the rotors to create friction. 

Over time, brake fluid can encounter several issues that can reduce its effectiveness. The largest issue with brake fluid is that it’s hygroscopic, meaning it absorbs moisture from its surroundings. This becomes an issue when moisture builds up within the brake lines and corrodes the sensitive components and lines it runs through. 

Water in your fluid is also an issue for it’s boiling point. Brake fluid naturally has a higher boiling point than it will ever reach in normal conditions, however when it’s diluted with moisture, the water can begin to boil at lower temperatures and lead to bubbles and air pockets within your fluid. As fluid becomes aerated, it won’t retain the same hydraulic properties and can affect your ability to brake. If your brake pedal feels “spongy”, it could be due to aeration in your brake fluid. 

Brake fluid may also leak from faulty lines or other seals, depriving your brakes of the fluid they need to safely stop your vehicle. If you see visible leakage on your master cylinder or brake lines, you should have your system inspected as soon as possible before the issue worsens. 

Symptoms of Bad Brake Fluid

The effects of old or contaminated brake fluid show themselves in several ways, but here are some symptoms you should keep an eye out for that may be warning you of the problem.

  • Soft or spongy brake pedal
  • The brake pedal sinks to the floor
  • Leaks around lines and master cylinder
  • Unusual noises and smells when braking
  • Decreased braking performance
  • Illuminated brake warning light on the dashboard

What Does a Brake Fluid Flush Cost?

Brake fluid flushes are best completed during regular brake jobs, as it can be cheaper to roll it in with services like pad and rotor replacements. However, as a standalone service, you can expect to pay anywhere between $100 to $200.

The price of your flush depends on many factors, including the vehicle itself, fluid capacity, and the type of fluid needed. 

Brake caliper and rotor

How Often Should I Have My Brake Fluid Changed?

In general, brake fluid flushes should be carried out every 2-3 years. The best source of information on brake fluid intervals though is the manufacturer themselves. Checking your owner’s manual, a trusted online source, or calling the dealer directly will give you an accurate picture of the proper interval.

That isn’t to say you should always wait for the maximum amount of time either. If you’re experiencing any of the above symptoms, it’s worth inspecting your fluid (or having a professional do so) to see if that could be the source of your issue. 

Brake Services at Sun Automotive

If you need fluid flush or any other brake service, trust the experienced technicians at Sun Automotive! Our team has the proper training and equipment to properly take care of your vehicle’s braking system, ensuring you can always slow down safely. We have four locations: two in Eugene, and one in both Springfield and Junction City. Give us a call or schedule online today to speak with our friendly advisors!