Can Brake Fluid go Bad?

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Important Tips on Changing Your Brake Fluid
Yes, brake fluid can go bad by absorbing moisture which leads to the accumulation of contaminating elements in the fluid. As your brake fluid attracts moisture, performance is reduced. Like all fluids in your car, brake fluid needs to be checked whenever you have the engine oil changed, yet it remains a maintenance item that many drivers ignore.

Don't Ignore Your Brakes!

Check your owner's manual to see when the automaker suggests your brake fluid should be drained and replaced and also to find out the specific kind of brake fluid your car uses. The service professions at Lithia Motors suggest that it is best to replace the brake fluid every two years so that your brakes continue to perform properly.
 
Some drivers ignore their brakes until they begin to fail due to thin brake pads. They just keep driving until they hear the squealing or grinding that means the brake pads are so thin that the calipers are contacting metal when the driver stomps on the brakes. Because being able to stop your vehicle is one of the most important functions of your car, it's extremely important to keep up with brake maintenance.
Al Lithia Motors our factory trained service technicians perform a multi-point inspection of your vehicle every time we change the engine oil and filter. This includes inspecting your brake fluid, your brake pads and rotors. When checking the brake fluid reservoir, the tech can check to determine if water has contaminated your fluid. If it has, we suggest the system will be drained and replaced with new brake fluid, then the brakes will be bled to get rid of any air bubbles in the system and checked to make sure your brakes are functioning as they should.
Why does Brake Fluid go Bad?
Many brake fluids such as DOT 3 and DOT 4 are known to be very hygroscopic; a term meaning that certain chemicals absorb moisture when exposed to air. Moisture can be absorbed in your brake fluid through the brake lines or the brake fluid reservoir even when the car is not being driven. Brake fluid can absorb moisture when it is poured into the brake reservoir or through daily use.
Why is the Boiling Point of Brake Fluid important?
After one year of service, your brake fluid will absorb approximately two percent of water and that decreases the "boiling point" of your brake fluid. When using the brakes, the brake pads grip the rotors to slow the vehicle. This causes the pads to get extremely hot and that heat is transferred to your brake fluid. In fact, your brake fluid can reach 390 degrees Fahrenheit. At that point, the fluid is boiling hot.


As you know from boiling water, as liquid begins to boil, air bubbles form and air in the brake lines leads to spongy brakes. When the brake fluid is heated passed its boiling point over and over, it causes braking to be less and less effective (known as brake fade). That is why the boiling point of your brake fluid is important.
 
Brake fluid manufacturers test the fluid for the Dry Boiling Point (ERBP) and the Wet Boiling Point (WERBP).
  • Dry Boiling Point measures the brake fluid boiling point of fresh new fluid right out of the container before it has been contaminated by water.
  • Wet Boiling Point measures the brake fluid boiling point after it has reached its average operating temperature and has a water contamination of 3.7 percent.
The minimum requirement for DOT 3 fluid is 284 degrees Fahrenheit and DOT 4 fluid's minimum requirement is 311 degrees Fahrenheit.
How long does Brake Fluid last?
Brake fluid manufacturers seal the bottles of brake fluid at the factory so that no air or moisture can contaminate the new fluid. That is why there is no expiration date on a sealed bottle of brake fluid. Shelf life depends on when the bottle has been opened and the amount of moisture it is exposed to. Most manufacturers suggest that an open bottle of brake fluid should be used within three months, and it should be discarded within a year. Also keep in mind that more moisture is absorbed through brake hoses and seals in areas known for high humidity in the air.




What does it feel like when you use the brakes?
A great indicator that it is time to have your brake fluid checked is that your brake pedal feels spongy or travels down nearly to the floorboard when you apply the brakes. That could mean your brake fluid has collected moisture or air in the lines. When you apply the brakes, the pedal should feel like you are pressing down on something solid.
Let Lithia Help
Don't forget, your brake fluid needs to be changed every two years. Let the trained professionals at your local Lithia Motors Service Center check your brakes the next time you stop by for an engine oil change. We'll check your brake pads and rotors, check your fluid, and if needed, drain and replace your brake fluid with the proper fresh DOT-approved fluid, bleed the brakes, and get you back on the road with many safe miles of driving ahead of you. Your safety is important to us because we want to keep you as a customer for life!