To assess the tightness of which component by pressing on it?

• A. Radiator hose
• B. Engine belt
• C. Alternator pulley
• D. Water pump

Answer: (B)

The tightness being checked is the drive belt. You test it by pressing on the belt in a flat span between pulleys and measuring how much it deflects. A properly tensioned belt should have only about half an inch (roughly 1 cm) of give when you press it. If you can push it in much more, the belt is too loose and can slip, which may cause the alternator to stop charging, the water pump to stop circulating coolant, or the power steering to lose assist—especially under engine load. If there’s no give at all, the belt could be too tight and put extra strain on bearings and the belt itself.

Other components are checked differently: the radiator hose is pinched to feel for cracks or softness; the water pump is inspected for leaks and proper mounting; and the alternator pulley is checked for wobble or play rather than belt deflection. Regularly inspecting belt condition and tension helps prevent belt slip or premature wear.