Who is correct about the functions of compression and cylinder leakage tests?

Focusing on the functions of compression and cylinder leakage tests, Technician B is correct in that these tests serve distinct but crucial roles in assessing engine health.

Compression tests measure the pressure generated in each cylinder during the compression stroke. This helps to reveal the condition of the piston rings, cylinder walls, and valves. A good compression reading indicates that the engine components are sealing properly, while low readings suggest issues that could stem from wear and tear or damage in these areas.

Cylinder leakage tests, on the other hand, evaluate how much air escapes from a cylinder when it is at the top dead center of the compression stroke. This test provides a more detailed assessment than a compression test. It can pinpoint specific problems, such as leaking valves, blown head gaskets, or worn rings, by measuring the percentage of air that escapes. A higher percentage indicates more leakage and, consequently, more significant issues within the engine.

Understanding the distinct functions of these tests is crucial for diagnosing engine problems accurately. Therefore, acknowledging that Technician B points out the specific applications of these tests emphasizes their importance in engine diagnostics and repair processes.