Q: How does brake fluid get dirty?

asked by on

How does brake fluid get dirty?

One way that brake fluid becomes contaminated is when moisture is absorbed by the brake fluid through rubber brake lines. This moisture will break down the brake fluid and cause rust in the brake system. Excess moisture in brake fluid will increase its temperature because the boiling point of water is lower than that of brake fluid. When this happens air gets into the brake lines and the brakes may become less effective. Brake fluid that has been contaminated by water or moisture can also weaken the master cylinder and caliper rubber seals and lead to brake leaks and an overall failure of the brake system. This type of contamination most commonly occurs in an environment that is particularly humid and in conditions of heavy braking. Another way that brake fluid becomes contaminated is when grime and debris from the brake system accumulates in the brake fluid. Over time, the heat that is generated from braking causes the brake fluid to break down and become contaminated. Brake fluid should normally be changed every two years but this is something that may already be included in the maintenance schedule for your vehicle. Pay close attention to the color of your brake fluid. Normal brake fluid should be a light yellow color and look almost clear, while contaminated brake fluid looks dark brown or black in color.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1,000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. How does brake fluid get dirty?

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Brake lines need bleeding.

If the brakes need excessive pressure to stop the car then you could have an issue with the brake booster is not working or leaking vacuum. the brake pads and rotors could be glazed and would require excessive stopping force...

Q: Break fluid leak

Hello, This may suggest that your brake pads are worn and due to be replaced or that you have a leak somewhere in your brake hydraulic system. The brake reservoir has a sensor inside that detects when the brake fluid...

Q: power steering is leaking / I have the pump/ pressure hose / belt

Any rubber component on a vehicle system is typically leak prone after about a 6 year lifetime particularly, for example, if you break the seal that a rubber hose in a power steering system makes to a nipple (on pump...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...