Castrol Brake Fluid DOT4 is a high boiling synthetic brake fluid which far exceeds the requirements of the SAE J1703,SAE J1704, FMVSS 116 DOT 4 , ISO 4925 and Jis K 2233 specifications. Castrol Brake Fluid DOT4 is designed for use in all brake systems particularly those which are exposed to extreme conditions. Application This product has been formulated from mixed polyalkylene glycol ethers and borate esters together with other high performance additives and inhibitors which give ultimate system protection against the effects of corrosion and high temperature vapour lock. The formulation has been developed such that the vapour lock point can be sustained at a higher level than conventional glycol ether based fluids during the service life of the product. Castrol Brake Fluid DOT4 is fully compatible with other fluids meeting FMVSS 116 DOT3 and DOT4 however , in order to maintain the superior performance characteristics of Castrol Brake Fluid DOT4 , avoid mixing with other brake fluids