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:

    Fuel filler door
    Press the button on the light switch panel (see the illustration on page 67) when the vehicle is at a standstill to unlock the fuel filler door. Please note that the fuel filler door will remain ...

    Passenger compartment filter
    Replace the cabin air filter with a new one at the recommended intervals. Please refer to your Warranty and Service Records Information booklet, or consult a trained and qualified Volvo servic ...

    Child seats
    Please refer to page 42 for information on securing child seats with the seat belts. ...