If a hydraulic governor has been refilled with oil, the engine should be operated until it reaches normal temperature, then the air should be purged, and the __________.

Correct Answer: Option C — compensating needle valve should be adjusted to stabilize operation

After servicing and bleeding a hydraulic governor, operating parameters stabilize once normal temperatures are reached. Final adjustments to the compensating needle valve are required to eliminate hunting or sluggishness, thereby ensuring steady-state engine speed control.