Brake Fluid SL DOT 4

Brake fluid SL DOT 4.
Contents: 1 liter.

When you apply the brake, the brake fluid ensures that the force is transferred from the brake pedal to the wheel cylinders. This requires a fluid. The brake fluid is very thin, so that it can easily move through narrow hoses and passages.

It is very important that the 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. These can be up to 500 degrees Celsius. The boiling point can be exceeded if, for example, you stop the car after prolonged braking. When brake fluid boils, vapor bubbles form which, unlike liquid, are compressible. The result: the brake system can build up less pressure and the performance of the brakes deteriorates drastically. In addition, brake fluid is hygroscopic, and since our classics do not have a 100% sealed system, water and corrosion will enter the system over time, which is why it is very important to replace the brake fluid every two years.

Brake fluid has two types of boiling point: dry (the boiling point of new, still-packaged brake fluid) and wet (the boiling point after absorbing about 3.2% water). In addition there are four different types of brake fluid, identified by a DOT number (Department of Transportation). The higher this number, the higher the boiling point of the brake fluid concerned.

The brake fluids are formulated on a polyglycol basis;

DOT 5 has the highest boiling point and is made on a silicon basis.

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

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

For our classics we use DOT 3 and DOT 4, as prescribed by Volkswagen, but how will you know which DOT to use for your car? It is very simple: the more heavily your brakes are usually loaded, the higher the boiling point of the brake fluid should be. Heavy vehicles and sports vehicles therefore benefit from a DOT 4 brake fluid with a high boiling point, and for standard brake systems DOT 3 is sufficient.

Mixing DOT 3 and DOT 4 is not recommended, although it does no harm to mix a higher version with a lower one.

Comes in a classic tin package.

Attention: Some manufacturers of brake parts recommend using only a specific brake fluid. Please note this. If this is the case, it is mentioned in the description.