Honda 1992 Civic Sedan Owner's Manual page 115

Cooling System
RADIATOR CAP
2. Turn the radiator cap counter-
clockwise, without pressing
down on it, until it stops. This
relieves any pressure remaining
in the cooling system.
3. Remove the radiator cap by
pushing down and turning
counterclockwise.
Maintenance
RESERVE TANK
4. The coolant level should be up to
the base of the filler neck. Add
coolant if it is low.
5. Put the radiator cap back on.
Tighten it fully.
6. Pour coolant into the reserve
tank. Fill it to halfway between
the MAX and MIN marks. Put
the cap back on the reserve tank.
Do not add any rust inhibitors or
other additives to your car's
cooling system. They may not be
compatible with the coolant or
engine components.
Replacing Coolant
The cooling system should be
completely drained and refilled
with new coolant according to the
time and mileage recommendations
in the maintenance schedule. Only
use recommended antifreeze.
Draining the coolant requires
access to the underside of the car.
Unless you have the tools and
knowledge, you should have this
maintenance done by a skilled
mechanic.