Castrol React Performance DOT 4 Brake Fluid SpecificationsCastrol React Performance DOT 4 brake fluid has been specially developed for use in the most severe conditions even during sports driving. It has been designed as an alternative to DOT 5.1 fluids for use in high temperatures.With a dry boiling point of 260°C (wet 180°C) it provides optimum protection against the formation of vapour locks while responding immediately to the slightest brake pedal input.Castrol React Performance is suitable for all disc and drum brake systems except those requiring mineral fluid. It exceeds the performance levels of FMVSS 116 DOT 3 and DOT 4 ISO 4925 SAE J1704 and JIS K2233.This product is miscible with DOT 3 DOT 4 and DOT 5.1 fluids but a complete draining and flushing of the system is recommended to preserve the maximum efficiency of Castrol React Performance DOT 4.