How To Test Your Brake Fluid Correctly

Think about how many times you use your brakes on an average drive, now think about how often you are likely to check your brake pads and discs, these parts both have visual indications of wear and tear, brake fluid however will often go unnoticed therefore unchanged.

Bendix Dot 3 and 4 Brake Fluids are Hygroscopic, meaning they will absorb moisture when exposed to air. The brake fluid absorbs moisture to prevent it from pooling and causing corrosion on metal components.

In order to determine the moisture content of your vehicles brake fluid, a test of the fluid’s boiling point must be performed. There are a number of testing tools available, however, some may not be as accurate as others.

Testers that use a conductivity measurement to produce a theoretical boiling point are not considered accurate as each tester is not calibrated to the manufacturer’s product it is being used on.

Bendix recommend using a fluid tester that boils a sample of the product to determine if the boiling point is above or below the manufacturer’s specified minimum boiling point. Bendix Dot 3 and Dot 4 Brake fluid have a minimum wet boiling point of 140 °C and 155 °C respectively.

It is important to remember that the system will continue to absorb moisture before the next service, so it is recommended to change brake fluid regularly to ensure your vehicle is safe.