Check the listing for details. Multi-Function Cylinder Leak Down Tester Gasoline Engine Compression Gauge Test. Condition: New. Listed at 34.98 USD. 【Features】: it is used to detect many common faults of the engine, such as piston ring wear, cylinder head crack, valve wear and cylinder head seal burst. It checks the amount of leakage in the engine cylinders and helps determine the source of the leakage. 【General accessories】: It is very suitable for testing trucks and models with minimum clearance. Check the leakage of the four stroke engine. 【How the leak tester works】: once the leak tester is connected to one of the cylinders, compressed air (0-100 psi) enters the cylinder through an integrated pressure regulator. Diagnose by observing the amount of leakage shown on the cylinder leakage gauge and listening to the leakage at all points of the vehicle system. It is not applicable to shallow cylinders.