Mercedes-Benz GL-Class: Braking - ABS (Anti-lock Braking System) - Driving safety systems - Safety - Mercedes-Benz GL-Class Owner's ManualMercedes-Benz GL-Class: Braking

If ABS intervenes when braking, you will feel a pulsing in the brake pedal.

If ABS intervenes: continue to depress the brake pedal with force until the braking situation is over.
To make a full brake application:

depress the brake pedal with full force.

The pulsating brake pedal can be an indication of hazardous road conditions, and functions as a reminder to take extra care while driving.

WARNING Do not pump the brake pedal. Use firm, steady 
Do not pump the brake pedal. Use firm, steady brake pedal pressure instead. Pumping the brake pedal defeats the purpose of the ABS and significantly reduces braking effectiveness.

    Important safety notes
    Observe the "Important safety notes" section. ABS regulates brake pressure in such a way that the wheels do not lock when you brake. This allows you to continue steering the vehicl ...

    Off-road ABS
    An ABS mode specifically suited to off-road terrain is activated automatically if the offroad drive program is activated or the LOW RANGE off-road gear is selected. At speeds below 18 mph(30 km ...

    See also:

    Brake Fluid
    The brake master cylinder reservoir is filled with DOT 3 brake fluid. See Engine Compartment Overview   for the location of the reservoir. There are only two reasons why the brake fluid ...

    Brake Adjustment
    Every time the brakes are applied, with or without the vehicle moving, the brakes adjust for wear. ...

    Active light function
    The active light function is a system that moves the headlamps according to the steering movements of the front wheels. In this way, relevant areas remain illuminated while driving. This allows ...