Rain brake support: How does this system work?

RBS - Rain Brake Support
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The rain brake support (or RBS in short) is a system of automatic drying of the brake discs, which helps to shorten the braking distance of the car. When driving in the rain, a water film forms on the brake discs, which reduces the effect of the brakes by delaying their onset.

The brake discs must first push out the water film or dry it to achieve the maximum braking effect.


How does the RBS system work?

With its function, the RBS system shortens the start-up time of the braking effect so that it can ensure short-term contact of the brake pads with the brake discs.

Just placing the brake pads on the discs will allow the brake discs to dry out, ensuring proper braking and, therefore, maximum braking effect. The system works completely automatically, and the driver may overlook its function.

The rain brake support is one of the active safety elements because it tries to prevent accidents by shortening the car's braking distance during adverse rainy weather.

How to turn on brake disc drying?

This system works automatically but needs a signal from the wipers and data on the car's speed for activation. If the wipers are on and the car travels at a speed higher than approximately 70 km/h, the rain brake support is active. This speed may differ between various manufacturers.

However, if the car driver wipes the windshield only once, the brake pads will only touch the discs once, and the brake discs will dry out only once. The system is then automatically deactivated.

Video animation of the RBS system