Ford Focus 2004 Owner's Manual page 210

Cooling system reservoir
The ignition must be
switched off before working
in the engine compartment.
Under some operating conditions,
the cooling system fan may
continue to run for several
minutes after the engine has been
switched off. This is quite normal.
Take care not to get any fingers or
clothing such as ties or scarves
caught in the fan.
To avoid scalding, never
remove the cap from the
coolant reservoir when the engine
is hot. Do not restart the engine
until the problem has been
eliminated.
The coolant level is visible through
the translucent reservoir. The
coolant level should be between the
MIN and the MAX mark when the
engine is cold. Hot coolant expands
and may, therefore, extend beyond
the MAX mark.
The coolant should be added when
the engine is cold. If coolant has to
be added when the engine is hot,
first wait 10 minutes for the engine
to cool. Unscrew the cap slowly.
Any pressure will escape while you
are turning the cap. Fully remove
the cap.
Maintenance
202