2 Symptoms Of Low Or Oxidized Brake Fluid
Just like every other driver, you've regularly replaced your brake pads and rotors when your brakes began causing performance issues. However, you've failed to also flush and replace your brake fluid. The brake fluid that flows throughout your vehicle is the lifeblood of your braking system. When your brake fluid is low or oxidized, these three issues will hinder your braking performance:
Soft Brake Pedal
When you first drove your vehicle, your brake pedal could bring you to a stop with almost no pressure. However, as you continued to use your brakes over the last several months or years, you've had to apply slightly more pressure to your pedal to achieve the same stopping performance.
Although many people attribute this issue to worn brake pads or rotors (which are also capable of causing this issue), the extra pressure required to bring your vehicle to a stop will be partially caused by your aging brake fluid. Although topping off your brake fluid reservoir will partially fix your soft, squishy brake pedal, you'll need to completely flush and refill your brake system to get your pedal back to normal.
Decreased Stopping Power
When you activate your brakes, you aren't just pressing your foot down on your pedal—you're pumping your master cylinder and sending brake fluid through your brake lines and into your brake assemblies. However, this hydraulic process is even more complex than it sounds. When your master cylinder pumps brake fluid throughout your lines, it increases the pressure of the fluid.
If you vehicle is low on brake fluid, then your master cylinder won't fully pressurize your fluid when you press on your pedal since there's empty space in your lines or fluid reservoir. As a result, you'll have to apply more pressure to your brake pedal to slow or stop your vehicle.
If your brake fluid is oxidized, which occurs when it experiences significant temperature fluctuations or absorbs moisture in the air, then it simply cannot be compressed as well as it could when it was new. Even though your fluid reservoir may be full, the stopping power of oxidized fluid simply doesn't compare to new fluid.
How To Prevent Brake Fluid Oxidation
Although you can easily tell when your vehicle is running low on brake fluid by checking the line on your brake fluid reservoir (located along the firewall on the driver's side of your engine bay), detecting dirty or oxidized brake fluid can be an extremely difficult task.
Instead of using only the age of your fluid to determine when you need a brake fluid flush, have your brake fluid electronically tested by your local mechanic every year. If you frequently drive along mountains, tow trailers, or under other conditions that increase the wear on your brake system, then have your fluid tested every six months. By doing so, you'll be able to detect signs of wear or oxidation well before your fluid causes performance issues.
Additionally, since fluid oxidation occurs as a result of moisture contamination, make sure your brake fluid reservoir's cap is always properly sealed. If your reservoir cap is slightly loose, then air will enter your reservoir each time you pump the brake pedal. If your cap is partially damaged, missing a gasket, or unable to create an airtight seal, then head to your local auto parts store to purchase a replacement.
If you're experiencing a soft pedal or a noticeable decrease in stopping performance, then have your fluid tested and replaced if necessary. Don't wait until these symptoms begin posing a serious threat to your safety to arrange for brake service. If you do, then you'll risk being involved in a car accident that may cause permanent injury or even death.