Did you know that most brake fluids absorb moisture and that fluid with a moisture content that is above 3-4% should be changed? As the concentration of moisture increases, it causes a sharp drop in the brake fluid's boiling point. This can be dangerous in today's high heat brake systems, particularly those with ABS. JEGS Brake Fluid Tester allows you to quickly determine the amount of moisture in your brake fluid so that you know when to change it.