Brake Fluids

High performance isn’t just about making cars go faster. It’s also about ensuring they stop safely.

Check it | change it | trust it

Never take a break from checking brake fluid. Make it part of every service.

At Castrol, and in Castrol partner workshops, we know high performance isn’t just about making cars go faster. It’s also about ensuring they stop safely. But even though brake fluid maintenance should be done as part of the regular vehicle service, 1 in 4 vehicles on the road have been found to have ineffective brake fluid. ^[1] The problem is that brake fluid absorbs moisture as it ages. As little as 3.5% water can reduce brake fluid effectiveness by up to 40%.

^[1] Periodica polytechnica transportation engineering. Operational tests of brake fluid in passenger cars, June 2019

Check it

Most manufacturers recommend a brake fluid change every 24 months (or 24,000 miles) but at Castrol we suggest checking at every service. Ideally with a professional testing machine.

Change it

Anything over 2.5% water content we’d recommend draining and changing the brake fluid. Over 3% water content and changing is essential.

Trust it

Castrol brake fluids are available in a range of formulations to suit every type of vehicle and driving situation.

Our fluids are engineered to have higher boiling points than standard fluids, providing extra assurance of brake fluid performance.

Giving you, and your customers, confidence that the vehicle can stop safely when out on the road. Or even out on the racetrack.

Never take a break from checking brake fluid.

Make it part of every service.

* Based on comparison of Castrol portfolio dry boiling point vs. ISO 4925

^Wet boiling point is temperature at which a dot fluid begins to boil after it has absorbed 3.7% Water by volume (equates roughly to 2 years service).

What do brake fluid DOT ratings mean?

All forms of brake fluid are given a DOT rating. DOT simply stands for ‘Department of Transport’, which sets the safety regulations for the acceptable performance of different brake fluids.

The DOT ratings given to brake fluids are based on the liquid’s dry and wet boiling points. As a rule of thumb, the higher the boiling point, the longer the lifespan of the brake fluid