Power brakes function only when the engine is running

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:
Coolant
Location of the coolant reservoir
Normally, the coolant does not need to be
changed. If the system must be drained, consult
a trained and qualified Volvo service technician.
See page 357 for i ...
Air vents in the dashboard
A - Open
B - Closed
C - Horizontal airflow
D - Vertical airflow
Direct the outer air vents toward the side windows to defrost. ...
Exterior
Partly because it was designed specifically as a sedan, the S80 looks
dramatically different than its squared-off predecessors. The compact grille
extends forward and is accented by a prominent V ...
