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:

    Children should be seated safely
    Volvo recommends the proper use of restraint systems for all occupants including children. Remember that, regardless of age and size, a child should always be properly restrained in a vehicle. Yo ...

    Symbols
    Wear protection gogg See owner’s manual for details Keep away from children Corrosive No smoking, no open flames, no sparks Explosion Recycle properly ...

    Whiplash Protection System (WHIPS) – front seats only
    The Whiplash Protection System (WHIPS) consists of specially designed hinges and brackets on the front seat backrests designed to help absorb some of the energy generated in a collision from the ...