Mercury Montego 2007s Owner's Manual page 249

Maintenance and Specifications
8. Add coolant/water mixture
through the thermostat housing
opening until full at housing
opening.
9. Install the thermostat housing
bleed plug. Install metal pin by
pushing into the slot.
After any coolant has been added, check the coolant concentration, refer
to the Checking engine coolant section. If the concentration is not
50/50 (protection to –34° F [–36° C]), drain some coolant and adjust the
concentration. It may take several drains and additions to obtain a 50/50
coolant concentration.
Whenever coolant has been added, the coolant level in the coolant
reservoir should be checked the next few times you drive the vehicle. If
necessary, add enough 50/50 concentration of engine coolant and
distilled water to bring the liquid level to the proper level.
249
2007 Montego (mgo)
Owners Guide (post-2002-fmt)
USA (fus)