Alpha Guard 4 is made from high molecular weight poly alkaline glycol ethers and borate esters, to give a high boiling point fluid of G 4 quality. The formulation has been developed in a way that the vapor lock point can be sustained at a higher level than conventional glycol ether-based fluids during the service life of the product. It contains inhibitors to prevent the corrosion of metallic brake components and to reduce oxidation at increased temperatures.