What is an important practice for accurate testing with a cylinder leakdown tester?

Listening carefully to all external orifices for audible leaks is crucial when using a cylinder leakdown tester because it allows the technician to identify the specific source of any air loss within the engine. When conducting a leakdown test, the technician introduces compressed air into the cylinder and then listens for hissing sounds or leaks from various locations, such as the intake manifold, exhaust system, or crankcase. Each of these areas can indicate different issues; for instance, a leak from the intake might suggest a problem with the intake valves, while a leak from the exhaust could indicate issues with the exhaust valves.

This practice provides immediate, observable feedback on the condition of the engine's components and allows for effective diagnostics. Such detailed listening helps the technician pinpoint problems that may need repair or further investigation, ultimately informing better service decisions.

In contrast, measuring engine pressure with a gauge, observing oil levels, or checking battery voltage, while important practices in their own right, do not directly contribute to identifying leaks during a cylinder leakdown test. They pertain to other aspects of engine health but do not assist in diagnosing air leaks within the combustion chamber itself.