The fluid in your hydraulic brakes doesn't last forever and needs to be changed every year or so. Many brakes use specific brake fluids that are not compatible with each other, so make sure you pick the proper fluid. The Maxima Bike Racing DOT 5.1 Brake Fluid is a high-performance brake fluid designed to lubricate and protect critical brake system componentry while providing reliable stopping power. It features an anti-vapor lock formulation that maintains responsiveness and performance by fighting both water contamination and vaporization. It resists corrosion, oxidation, and is compatible with SBR, EPDM, and natural rubbers. This fluid mixes with other DOT 3, DOT 4, and DOT 5.1 brake fluids.