FAA Powerplant Written Practice Test

What position should the piston be in to remove pushrods from an engine?

1. Bottom dead center

2. Top dead center after the intake stroke

3. Top dead center following the compression stroke

4. Mid-stroke completion

The correct answer is: Top dead center following the compression stroke

To safely remove the pushrods from an engine, the correct position for the piston is top dead center following the compression stroke. At this position, both the intake and exhaust valves are closed, which means there is no pressure in the combustion chamber. This is crucial because if the valves are open or there is residual pressure in the cylinders, force may be exerted on the pushrods, making them difficult or unsafe to remove. Positioning the piston at top dead center after the compression stroke ensures that all moving parts are in their resting position, minimizing the risk of any unintended movements or damage. This precaution helps facilitate safe maintenance procedures and protects both the engine components and the technician performing the work.