What transforms your foot pressing on the pedal into the force that stops your vehicle? A crucial part of that process occurs in your brake lines. The brake fluid within these lines generates the hydraulic pressure needed to activate your brakes. If the brake fluid level drops too low, the brake lines struggle to build enough pressure, causing the pedal and other components of your braking system to work harder to stop the vehicle. A significant loss of pressure can lead to brake failure.
Common Brake Fluid Issues
Hydraulic pressure in your brake lines can decrease for several reasons related to various brake components, but three common themes are:
1. Brake Fluid Loss
2. Air in the Brake Lines
3. Old or Contaminated Brake Fluid
Regardless of the specific issue, the first step is always to conduct a brake inspection.
How Does Air Enter Your Brake Lines?
Over time, normal wear and brake fluid leaks can cause a vehicle’s brake fluid level to drop. This drop creates a vacuum that allows air to enter the brake lines. The brake line system isn’t perfectly airtight, and every time someone checks the brake fluid level, it is exposed to the air.
What Happens When Brake Fluid is Old or Contaminated?
Brake fluid contains additives to prevent corrosion and degradation. Like motor oil, it should be changed periodically to maintain its protective qualities. Brake fluid can become contaminated as it absorbs moisture from the air each time the cap to the master cylinder is removed. Over time, this moisture can lead to rust and corrosion of the internal metal parts of your brake system.
Why Is My Brake Fluid Low?
Brake fluid levels can drop due to leaks or normal brake operation. As brake pads or shoes wear down, they create more space between themselves and the brake rotors or drums. More brake fluid is then required to fill this space and reach the wheels, leading to a decrease in fluid levels.
What Happens When Brake Fluid is Low?
Low brake fluid can lead to air entering your brake lines, resulting in a spongy pedal. This can escalate to a critical loss of hydraulic pressure and potential brake failure. If the low fluid level is due to normal operation, the decline will be gradual; however, allowing it to get too low can introduce air into costly components like your anti-lock brake system. If you suspect a brake fluid leak, you may not know how quickly your brake performance could diminish. If you notice any changes in your brake response or signs of a leak, have your brakes inspected as soon as possible.
What Color is Brake Fluid?
Fresh brake fluid can range from colorless to light brown or amber, while older fluid often appears darker brown. Deteriorating brake fluid can contain debris that may erode the seals of your master cylinder and brake calipers over time. However, color alone isn’t a reliable indicator of when to replace your brake fluid.
Instead of depending on color to gauge when to change the fluid, the Automotive Maintenance and Repair Association’s (AMRA) Motorist Assurance Program (MAP) recommends having brake fluid tested by a qualified technician. Monty’s Automotive can assess your brake fluid for the depletion of corrosion inhibitors and check for incorrect fluid types, among other things.