Oil Leak and Valve Guide Seal Test

The cylinder leakage detector tests for engine oil leaks and checks the valve stem seals for leakage.
1. Plug all crankcase openings except the one used for connecting the leakage detector.
2. Connect the detector to a crankcase opening (an oil level indicator tube is convenient). Adjust the air pressure to approximately 34 kPa (5 psi).
3. Using a solution of liquid soap and water, brush the solution along the gasket sealing surfaces and bearing seals. Look for bubbles or foam.
4. Remove the spark plugs and rotate the engine slowly with a wrench. Check for large amounts of air escaping into the cylinders as each exhaust valve and intake valve opens.
5. The spark plugs on the leaking cylinders will probably show deposits of burned oil.