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:

    Hood and engine compartment
    Turn the handle located under the left side of the dash approximately 20-25 degrees clockwise to release the hood lock. Lift the hood slightly. Press the release control (located under the r ...

    Bluetooth streaming audio (BT)
    The vehicle's audio system is equipped with Bluetooth , which makes it possible to play streaming audio files from a Bluetooth device such as a cell phone or personal digital assistant (PDA). N ...

    Polishing and waxing
    • Normally, polishing is not required during the first year after delivery, however, waxing may be beneficial. • Before applying polish or wax the vehicle must be washed and dried. Tar spots can ...