The Model 3/Y braking system is filled with DOT 3 fluid at the factory. If your brakes reach a high temperature, which they will with spirited road driving or when on track, DOT 3 may boil resulting in loss of performance and a 'long pedal'. Replacing the DOT 3 fluid with high performance DOT 4 will guard against this. 

We recommend Castrol React Performance DOT 4 for road and occasional track use. If you intend to track your car regularly, you should consider using Castrol React SRF, which is widely acknowledged to be the best brake fluid available.

The Model 3/Y requires approx. 1.5 litres of new brake fluid to replace the existing fluid completely. We recommend draining the system and flushing with a small amount of new fluid before refilling and bleeding, so you will need to order at least 2 x 1 litre bottles.

Castrol React Performance DOT 4 is a high boiling synthetic brake fluid which far exceeds the requirements of the SAE J1704, FMVSS 116 DOT 3 and DOT 4, ISO 4925 and JIS K2233 specifications. This product has been formulated from mixed polyalkylene glycol ethers and borate ester together with other high performance additives and inhibitors which give ultimate system protection against the effects of corrosion and high temperature vapour lock. Castrol React Performance DOT 4 brake fluid is designed for use in all brake systems particularly those which are exposed to extreme conditions such as high performance vehicles and race conditions.

Castrol React SRF Racing brake fluid is a high performance brake fluid of special value in competitive motor sport where extreme braking conditions are encountered. It is an exclusive Castrol product registered under patents in many countries. Castrol React SRF Racing exceeds US Federal Standards FMVSS 116 DOT 3 and DOT 4, ISO 4925, JIS K2233 and current SAE J 1703 specifications.

Castrol React SRF has been especially formulated to maximise braking performance under arduous competitive conditions. In order to achieve the optimum benefits in such applications, advanced materials have been employed in a unique and patented Castrol formulation. The use of Castrol React SRF should be restricted to not more than eighteen months before draining and refilling for maximum efficiency. Prolonged use in excess of the recommended period may give rise to a deterioration in performance at very low temperatures. Castrol SRF is suitable for all disc and drum brake systems with the exception of those for which mineral oil is prescribed.

Note: 2 x 1 litre bottles required to fully flush the brake system in a Model 3/Y.

*** Sorry, but we are unable to ship brake fluid outside the UK ***