So, a compression test is a “dynamic test” (engine moving). Learn how it works, what the results mean, and how to diagnose engine health like a pro. You fill one of your cylinders with compressed air and measure how much of it is leaking out of the cylinder
Understanding Leakdown Tests
What is a leak down test
A leak down test is a method of using compressed air and a specialized gauge set that reads differential pressure to evaluate the condition of an engine’s cylinders, pistons and rings, and valves and seats without disassembling the engine.
The cylinder leak down test allows diyers and professionals to assess the integrity of an engine’s internal components This test, indispensable for measuring the capability of an engine to hold pressure, is an integral part of any thorough engine health assessment due to its ability to pinpoint issues that rob you of power and reliability. Leak down is the percentage of compression that is lost by the engine, and every engine has some Like a compression test, a leak down test is accomplished by replacing a spark plug with the tester hose
Unlike a compression test, a leak down tester has two gauges and requires a compressed air source One of the gauges on the tester shows the pressure at which the cylinder is being pressurized.
