When it is wet, a thin film of water coats the brake disks, meaning the service brake responds poorly. During a journey, dry braking improves the response time of the service brake because the brakepads strip the water film off the brake disks.
Function requirements
Engine in operation
Drive train operational
Brake and traction system functional
No brake intervention by a driver assistance system
Vehicle speed > 50 km/h
Windshield wiper system switched on
Function
In order to strip the water film from the brake disks, the brakepads are applied to the brake disks for a brief period (approx. 1.1 s) with a brake pressure of p = 1 bar.
After dry braking, the brakepads return to their default position.
Dry braking is performed cyclically and without any driver intervention.