Honda Civic Service Manual: Engine Cooling

Engine

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Coolant Replacement (R18A9)

1. Radiator Cap 1. Wait until the engine is cool, then carefully remove the radiator cap. ...

See also:

Honda Civic Owners Manual. Accessories
When installing accessories, check the following:  Do not install accessories on the windshield. They can obstruct your view and delay your reaction to driving conditions.  Do not install accessories over areas marked SRS AIRBAG, on the sides or backs of the front seats, on ...