What should an aircraft technician do if they suspect a hydraulic lock?

In the scenario where an aircraft technician suspects a hydraulic lock, the correct action is to pull the propeller to relieve pressure in the cylinders. Hydraulic lock occurs when fluid accumulates in one or more cylinders, preventing the piston from moving freely. This situation can prevent the engine from turning over during starting attempts and may lead to severe engine damage if not addressed properly.

By pulling the propeller through its full range of motion, the technician can evacuate the fluid from the locked cylinder, allowing the piston to move freely again. This method is a safe way to relieve the condition without damaging the engine components.

Other actions, such as starting the engine at a higher RPM or turning off the fuel to crank the engine, could lead to further complications or damage if the engine does not start due to the hydraulic lock. Performing a full engine disassembly is too extreme and unnecessary unless there are indications of more severe internal damage after the hydraulic lock is addressed.