Leak Down Tester
A diagnostic tool that identifies air leaks within engine cylinders.
A leak-down tester pressurizes individual cylinders with compressed air and measures how much escapes. Listening for hissing helps locate leaks through valves, piston rings, or head gaskets. Unlike compression tests, this method provides a percentage of leakage, offering a more precise diagnosis. It's a standard practice for pre-purchase inspections and engine rebuild assessments. Consistent results across all cylinders indicate a well-sealed engine. This test complements compression testing for complete mechanical analysis.
Related Diagnostic Guide
This topic is part of CHEPQ’s system-level diagnostic framework.
For a broader understanding of how this component is analyzed in real-world diagnostics, refer to the following guide:
Applying This Knowledge in Practice
The diagnostic principles discussed above are commonly applied in real-world vehicle diagnostics. To put this knowledge into practice, explore professional automotive diagnostic tools designed to support system testing, fault analysis, and troubleshooting across modern vehicles.