HAYES DOT 5. 1 BRAKE FLUIDHydraulic disc brakes need to be bled every year or so in order to make sure your brakes are working optimally. The fluid in your brakes will start to become gummy which lowers your braking performance. The Hayes DOT 5. 1 Brake Fluid is designed to work with Hayes brakes and any brake that uses DOT 5. 1 fluid. It is available in both 16oz and 4oz sizes. Features Available in two sizes including 16oz and 4oz Designed for brakes that use DOT 5. 1 fluid | Hayes | Dot 5. 1 Brake Fluid 4Oz