See also:

Checking the Engine Oil
Engine oil is essential to the performance and service of the engine. It is suggested that you check the oil level at least once a week in normal use and more often if you are on a trip or driving ...

Air conditioning refrigerant
Check the air conditioning lines and connections for leakage and damage. ...

Vacuum crankcase ventilation hoses
Inspect the surface of hoses for evidence of heat and/or mechanical damage. Hard and brittle rubber, cracking, tears, cuts, abrasions, and excessive swelling indicate deterioration. Particular att ...