What is the purpose of a cylinder leak down gauge?

A cylinder leak down gauge is specifically designed to assess the integrity of an engine's cylinder sealing. It works by pressurizing the cylinder with compressed air and measuring how much air escapes. This allows technicians to determine if there are any issues such as worn piston rings, leaking valves, or head gasket failures. Proper sealing is essential for optimal engine performance, efficiency, and power output; thus, identifying leaks plays a crucial role in diagnosing engine health.

The other options do not relate to the function of a cylinder leak down gauge. Measuring fuel pressure pertains to the fuel delivery system and ensures that adequate fuel reaches the engine. Verifying oil levels in the crankcase relates to lubrication and engine operation but does not involve cylinder sealing. Measuring coolant temperature is important for understanding engine cooling systems but also does not connect to the purpose of assessing cylinder integrity.