Power brakes function only when theengine is running

Power brakes function only when theengine is running  - Brake system - Starting and driving - Volvo XC90 Owners Manual - Volvo XC90

The power brakes utilize vacuum pressure which is only created when the engine is running.

Never let the vehicle roll to a stop with the engine switched off.

If the power brakes are not working, considerably higher pressure will be required on the brake pedal to compensate for the lack of power assistance. This can happen for example when towing your vehicle or if the engine is switched off when the vehicle is rolling. The brake pedal feels harder than usual.

    See also:

    Tire sealing system–temporarily repairing a flat tire
    Temporarily repairing a flat tire is done in two stages: • Stage 1: The hole is sealed by pumping sealing compound into the tire. The car is then driven a short distance to distribute the sealing ...

    Marker lines
    1 - Marker line for a 1-foot (30-centimeter) zone behind the vehicle 2 - Marker line for the clear back-up zone 3 - "Wheel tracks" The solid line (1) indicates a zone within 1 ft (30 ...

    Blower control
    Turn the control clockwise to increase or counterclockwise to decrease the blower speed. If AUTO is selected, blower speed will be regulated automatically and this will override manual adjustment. ...