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What Can Cause Your Brake Light To Come On

Any time a light on your dashboard illuminates, such as the check engine light, it’s likely to ruin your day. A brake light though may send you into a panic. What causes the brake light to come on may be something minor, meaning it may not be necessary to pull over and have your car towed to the shop. Still, if your brake light is on, your car is communicating that the brake system needs attention. Let’s look at what often causes the brake light to come on.

When the brake pedal is pressed, the force that is created is transferred to the brakes via brake fluid. Because brakes need a significant amount of force to stop your vehicle, the pressure must be magnified. With the use of friction and resistance, the brakes transfer the motive energy into heat energy with hydraulic force. The fluid moves through the brake lines to create the pressure needed to force the brake shoes or pads to press on the rotors or drums to stop the vehicle.

Brakes are imperative to the safety of your vehicle and it’s important to make sure they are in good operating condition. The brake light can illuminate for any number of reasons if the parking brakes are the cause, for example, you can simply disengage it to deactivate the light. However, an expert will need to determine what causes the brake light on the dash to stay on. The most common reasons your brake light is on:

  • The Parking Brake is engaged
  • Brake Fluid is low or leaking
  • Worn brake pads
  • The ABS System has failed
  • Brake lights burned out
  • Faulty sensors

Parking Brake Engaged

Many vehicles are equipped with a sensor that is able to determine whether the parking brake is engaged or not. If the parking brake is on, even if it appears not to be, the sensor will cause the brake light to illuminate to let the driver know it is engaged. Driving with the parking brake on can result in damage to brakes by overheating, wearing down the lining of brake shoes or pad, or compromising the integrity of the brake fluid.

Brake Fluid Low or Leaking

A sensor placed in the master cylinder is able to determine the level of fluid within the system. When the level falls below where it should be, the sensor triggers the brake light. Maintaining a proper level of brake fluid is essential to your brake’s operation. Often found under the hood, the plastic brake fluid reservoir is made to help you identify the level of fluid in the system without removing the cap (as you would with your oil reservoir). This helps to prevent moisture or dust from entering the system, contaminating the fluid.

Brake system warning light in car dashboard

Low brake fluid can also be a sign of worn brake pads. As the material wears from the friction, the brake fluid forces the pistons out against the pads into the brake disc, to help create enough stopping power. As a result, this causes the brake fluid to fill the gap, reducing the fluid in the reservoir. Replacing the brake pads may resolve the issue.

If the brake pads are not worn, it’s possible a leak is the cause of the reduction in brake fluid. A technician will need to inspect the brake fluid reservoir, brake lines, connections, valves, brake mechanisms, and rubber hoses. If you identify a clear or orange-tinged fluid leaking onto the ground, the vehicle should be inspected immediately.

Worn Brake Pads

Many vehicles are equipped with a sensor that alerts drivers when their brake pads are worn, by activating the brake light or by producing a screeching sound. Don’t wait to replace your brake pads. Over time, the friction material wears out resulting in metal to metal contact with the rotors, which can permanently damage brake components and result in costly repairs.

ABS System

Troubles within the ABS system can cause the brake light to come on. If the brake fluid is full and the parking brake is not engaged, a technician will need to scan the vehicle’s internal computer for codes in order to repair the issue.

Brake Light Bulbs

Most vehicles have many bulbs in the brake lights. Even if one bulb burns out, the vehicle’s computer may recognize a change in the circuit and switch on the brake light.

Faulty Sensors

The sensors that measure brake fluid levels and determine if the parking brake is engaged, can fail, producing false errors and illuminating the brake light. A technician specializing in brake systems should inspect the vehicle to determine which sensor has failed and replace it properly.

Brake problems are a serious issue, if the warning light is accompanied by vibrations or brake noises, don’t hesitate to get your car inspected at an auto center. If the brake system doesn’t feel right, fails to respond immediately, the brake pedal goes to the floor, or you need to pump the brakes to stop, avoid driving at all costs and have your vehicle towed to a service center right away.

Brakes are one of the most important safety features on your vehicle. If you’re concerned about the state of your brakes, a Certified Technician should check to ensure they are functioning properly. Brake Experts, like the kind you’ll find at Sun Devil Auto, are exactly what you need for honest, straightforward advice on how to care for your brakes. Our experienced technicians will perform a brake inspection that includes a measure of the thickness of the rotors and drums and the brake pads and shoes, as well as a check for leaks in the hydraulic system, absolutely free! Our Technicians are ASE Certified and possess the experience to repair and maintain all areas of your vehicle, especially brakes. Stop into a Sun Devil Auto today and see for yourself!