Honda Civic Service Manual: Radiator

Thermostat Housing Removal and Installation (R18Z1)

1141B6 1. Radiator Cap 1. Wait until the engine is cool, then carefully remove the radiator cap. ...

Radiator Connecting Pipe Removal and Installation (K24Z7)

1141E7 1. Radiator Cap 1. Wait until the engine is cool, then carefully remove the radiator cap. ...

See also:

Honda Civic Owners Manual. Changing the Engine Oil and Oil Filter
You must change the engine oil and oil filter regularly in order to maintain the engine's lubrication. The engine may be damaged if they are not changed regularly. Change the oil and filter in accordance with the maintenance message on the information display*/driver information interface*. ...