While performing a cylinder leakage test, technician A says that 20% leakage is acceptable. Technician B says that a cylinder will show too much leakage if the piston is not at TDC on its compression stroke. Which technician is correct?

Question

Quizplus · Accepted Answer

Technician A is correct because a general rule of thumb is that up to 20% leakage can be considered acceptable in many engines. Technician B is also correct because performing a cylinder leakage test with the piston not at Top Dead Center (TDC) on its compression stroke can result in inaccurate readings, showing excessive leakage due to the valves being open or not fully seated.

While Performing a Cylinder Leakage Test, Technician a Says That