Question 37 UFIV01 - Chief Engineer - UFIV

The Correct Answer is C ### Explanation for Option C (Correct) **C) The engine driven pump (H) drive belt is broken.** The engine-driven pump (H) is the component responsible for automatically recharging the accumulator (A) while the main engine is running. If the drive belt for this pump is broken, the pump cannot turn, meaning it cannot generate the high-pressure fluid necessary to maintain the accumulator in a fully charged state. Since the system works when charged manually (via the hand pump) and the engine successfully starts, we know the accumulator and starter components are functional. The failure to maintain the charge while running directly isolates the problem to the automatic charging mechanism, which is the engine-driven pump and its drive system. ### Why Other Options Are Incorrect **A) The hydro starter (C) pistons are worn.** Worn pistons in the hydro starter (C) would primarily affect the downstream usage of the pressure, resulting in the engine failing to start, or starting weakly, due to internal leakage. Since the engine successfully starts, the starter is operating adequately. This wear would not directly prevent the pump from recharging the upstream accumulator. **B) The unloading valve (I) is set for too high a pressure.** The unloading valve (I) controls the maximum pressure the accumulator can reach. If it were set too high, the system would struggle to reach that elevated maximum pressure, but it would still achieve the necessary operational charge pressure unless the pump failed entirely before reaching the setting. If the system were failing to charge at all, the valve is more likely set too low (releasing pressure prematurely), or the pump is not functioning—a broken belt (C) represents a complete pump failure. **D) The full-flow filter (G) is bypassing the element.** Filter bypass occurs when the filter element is clogged, allowing oil to flow around the element to prevent pump starvation. While bypassing the filter indicates a need for maintenance and results in dirty oil, it does not significantly restrict the flow or pressure output of the pump enough to prevent the accumulator from being charged successfully. The pump is still supplying fluid, just unfiltered fluid.