What is the purpose of a Cylinder Leakage Test?

The purpose of a Cylinder Leakage Test is to identify and quantify leaks in the combustion chamber compared to the results obtained from a compression test. This test involves applying air pressure into the cylinder while it is at top dead center on the compression stroke. By measuring the amount of air that escapes and where it escapes from (such as the intake or exhaust valves or through the piston rings into the crankcase), mechanics can determine the condition of the internal components of the engine.

A Cylinder Leakage Test provides more detailed information about the engine's sealing capabilities than a compression test alone. While a compression test measures the overall pressure in the cylinder, the leakage test pinpoints specific areas of concern, which is crucial for diagnosing issues that may not be apparent through compression testing. This makes it an essential tool for maintaining engine health and performance.