Product description

When you apply the brake, the brake fluid ensures that the force exerted on the brake pedal is transmitted to the brake cylinders in the wheels. This requires a fluid because fluids are not compressible, so any pressure force is transmitted directly. Brake fluid is also very thin, making it easy to pass through pipes and narrow passages.

It's very important that brake fluid has a high boiling point, because the modest amount of brake fluid in your car has to withstand the very high temperatures that occur during braking (up to 500 degrees). The boiling point may be exceeded if, for example, you stop the car after prolonged braking. When brake fluid begins to boil, vapour bubbles form. Unlike liquid, these vapour bubbles are compressible. The result is a drop in pressure in the braking system, and brake performance deteriorates considerably. What's more, brake fluid is hygroscopic, and as our classics don't have a 100% dense system, water and corrosion penetrate the system over time, making it all the more important to replace brake fluid every two years.

Brake fluid has two types of boiling point: dry (the boiling point of new brake fluid) and wet (the boiling point after absorption of around 3.2% water). In addition, there are four different types of brake fluid, indicated by a DOT (Department of Transport) number. The higher the number, the higher the boiling point of the corresponding brake oil.

Brake fluids are formulated with polyglycerol;

DOT 5 has the highest boiling point (also above 5.1) and is formulated from silicon.

DOT 3 has a dry boiling point of 190°C and a wet boiling point of 140°C.

For other numbers, the following applies: DOT 4 (205/155), DOT 5.1 (230/180) and DOT 5 (260/210).

For our classic cars, we use DOT 3 and DOT 4, as Volkswagen also prescribes, but how do you know which DOT to get for your car? It's very simple: the heavier the load on your brakes, the higher the boiling point the brake fluid should be able to withstand. Heavy and sporty vehicles therefore benefit from DOT 4 brake fluid with a high boiling point, while DOT 3 is sufficient for standard braking systems.

It is not recommended to mix DOT 3 and DOT 4, although it is not dangerous to mix a higher version with a lower one, especially not the other way round.

DOT 3 has a blue color, which can be mixed with yellow DOT 3. The mixed color then turns green, but has no effect on performance - apart from color, it's identical.

Supplied in a 1-liter classic look can.

Note: Some brake parts manufacturers only recommend the use of a certain brake fluid, so please follow this advice. If this is the case, it will be mentioned in the description.