Whilst most drivers are aware of the importance of engine oil and screen wash, brake fluid is frequently overlooked. Yet this humble fluid plays an absolutely critical role in your vehicle’s ability to stop safely. At Brookes Auto Repair, we check brake fluid condition on every vehicle that comes through our doors — and what we find is often concerning.
What Is Brake Fluid and What Does It Do?
Brake fluid transmits the hydraulic pressure generated when you press the brake pedal through the braking system to the callipers and wheel cylinders. Without it, your brakes simply would not function.
Why Does Brake Fluid Degrade?
Brake fluid is hygroscopic, meaning it absorbs moisture from the atmosphere over time. As moisture content increases, the fluid’s boiling point drops. During heavy braking, the fluid can overheat and vaporise — a condition known as vapour lock — causing the brake pedal to feel soft or sink to the floor. This is a serious and potentially fatal safety hazard.
How Often Should It Be Changed?
Most vehicle manufacturers recommend replacing brake fluid every two years, regardless of mileage. A moisture content test — which we carry out as standard during servicing — can give a more precise indication of condition. If the fluid tests above 3.5% water content, replacement is recommended immediately.
Signs Your Brake Fluid Needs Attention
A spongy or soft brake pedal, a pedal that sinks slowly toward the floor, or a warning light on your dashboard relating to the braking system are all signs that your brake fluid may need attention. Book a brake inspection at Brookes Auto Repair at brookesautorepair.com.
