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. It is designed for use in all brake systems, particularly those exposed to extreme conditions. This product is formulated from mixed polyalkylene glycol ethers and borate esters, along with high-performance additives and inhibitors that provide ultimate system protection against corrosion and high-temperature vapor lock. The formulation sustains a higher vapor lock point than conventional glycol ether-based fluids throughout the product's service life. Castrol Brake Fluid DOT4 is fully compatible with other fluids meeting FMVSS 116 DOT3 and DOT4; however, to maintain its superior performance, avoid mixing with other brake fluid products. All conventional brake fluids degrade during use, so it is strongly recommended to change Castrol Brake Fluid DOT4 according to the vehicle manufacturer's advice, or every 2 years if no specific advice is given. Exercise caution when handling, as spills on paintwork can cause damage; rinse affected areas with water immediately without wiping. This fluid should not be used in braking systems recommending mineral oil-based fluids, such as certain Citroen systems (where Castrol LHM plus is suitable) or Rolls Royce vehicles (for which Castrol CHSMO Plus is approved).