It’s unsettling to see your brake light illuminate on the dashboard. This warning indicator often signals a problem within your vehicle’s braking system, and understanding the cause is crucial for safety. One common reason for the brake light to turn on is low brake fluid.
There are primarily two main reasons why your brake fluid level might be low, triggering the warning light. The first is due to the natural wear of your brake pads over time. As brake pads become thinner with use, more brake fluid is drawn into the calipers to compensate for the reduced pad thickness. This gradual process leads to a decrease in the brake fluid reservoir level, eventually activating the brake light sensor.
Another potential cause, especially if you drive aggressively or frequently brake hard, is boiling brake fluid. When brake fluid overheats, it can boil, becoming thinner and potentially leaking out of the bleeder valves. This fluid loss also results in a lower reservoir level and consequently, the brake light turning on. Boiling brake fluid can also damage your calipers.
Using the correct type of brake fluid is important. While DOT 3 brake fluid might resolve the immediate issue of low fluid, it has a lower boiling point compared to DOT 4 and DOT 5.1 fluids. For enhanced braking performance and to prevent fluid boiling, especially under demanding driving conditions, consider upgrading to DOT 4 or DOT 5.1 brake fluid. However, avoid using DOT 5, which is silicone-based and not compatible with most standard brake systems. Motul RBF600 is a widely recommended high-performance brake fluid if you frequently engage in hard braking.
Instead of simply refilling brake fluid every time the light comes on, it’s essential to diagnose the underlying cause. Determine if worn brake pads are the issue or if you need a brake fluid with a higher boiling point. Addressing the root problem, whether it’s replacing worn pads or upgrading your brake fluid, is a more effective long-term solution to prevent the brake light from repeatedly turning on and ensures your braking system operates reliably.
