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  • Writer's pictureAndrew Aragon

The Most Overlooked Car Maintenance Item: Brake Fluid

When you think about car maintenance, you probably consider oil changes, tire rotations, and maybe even replacing brake pads. But have you ever thought about brake fluid?

It’s one of the most crucial, yet often overlooked, components that keep you safe on the road.

However, like any other component of your vehicle, brake fluid doesn’t last forever. Over time, it can become contaminated or lose effectiveness, risking your safety.

brake fluid reservoir

Why Brake Fluid Matters

Your brakes are essential for safe driving, and they rely on brake fluid to function properly. This fluid plays a key role in ensuring your brakes, including the pads, rotors, and calipers, work efficiently. Neglecting brake fluid maintenance can lead to serious problems.

The Role of Brake Fluid in Your Vehicle

Brake fluid has many vital workings in the braking system.

  • It's the critical hydraulic agent that makes everything happen.

  • It's used to apply the brakes to stop the car.

  • It's used by the ABS unit, your Anti-Lock braking system.

  • It's also used by your Traction Control, most times you do not know it is being applied.

What happens if you don’t change out your Brake Fluid?

  • Brake fluid is hygroscopic, which means it attracts moisture from the air. Living in a desert, you would assume that there's no moisture in the air for it to draw from, but there is enough for the brake fluid to be affected. Also the brake fluid reservoir is located in the hot engine bay, and condensation does happens inside the fluid reservoir.

  • Too high of moisture content in the brake fluid will cause the fluid to become more acidic, and acidic brake fluid will start eating away at the metal in the system. Components like the fluid lines, master cylinder, brake calipers and Anti-Lock/Traction control units.

  • High moisture content in the brake fluid lowers the boiling point of brake fluid, which in turn affects the stopping of the vehicle. The brakes naturally generate heat, so the heat transfers into the brake fluid inside the caliper, and then the brake fluid can start to boil which causes you to lose braking ability. Like vehicles coming down a steep mountain road. Brakes are getting very hot, brake pedal becomes spongey or worse yet goes to the floor, causing the driver to lose the ability to brake their vehicle. Not a good scenario to be in at all.

Porsche had a problem in the late 90’s cars as they used a different supplier of brake fluid and the owners of the vehicles didn’t follow Porsche’s recommend flush intervals. A white paste would form in the ABS unit, damaging the hydraulic valves in the unit itself. Turned into a very expensive repair!

How Often Should Brake Fluid be Changed?

  • The most common brake fluid change out recommendations for European cars are every 2 years, or for every 30,000 miles driven, whichever one comes first.

If you're unsure of when the brake fluid was last changed, or where you are at with your mileage tracker, here are some common signs to look out for:

  • Discolored Brake Fluid. Old brake fluid will change from its nice gold color to a black, green, or even red color. This is when the moisture content is very high, 4% or more.

  • If your brake pedal feels almost spongy when you press down on it.

  • Diminished braking, stopping distances become longer.

Green Brake Fluid With Very High Moisture Content That Needs To Be Changed
Green Brake Fluid With Very High Moisture Content That Is Bein Flushed Out.

Where can I get my Brake Fluid Serviced?

The experts at Stuttgart Autohaus will make sure the brake fluid on your VW, Mercedes, Volvo, Porsche and Audi is still performing correctly or needs to be changed, keeping you save on the road.

Call us today at 520-884-8800 or visit us here and let know your concerns.


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