What pressure reading indicates that the pressure is too low in the hydraulic system?

The correct pressure reading that indicates the hydraulic system is too low is below 750 PSI. In hydraulic systems, maintaining specific pressure levels is critical for proper operation, as they ensure efficient functioning of hydraulic components such as pumps, actuators, and control surfaces.

A pressure reading below 750 PSI signals a potential failure or malfunction within the hydraulic system. Operating at or above this threshold typically ensures that the system can effectively transmit power and operate its components. Pressure below this recommended level could lead to inadequate performance of the hydraulic system, potentially impairing the responsiveness and effectiveness expected during operation.

Other thresholds, such as the ones indicated by the other answer choices, might represent different operational parameters but are not indicative of the critical low-pressure malfunction threshold that would necessitate immediate action or inspection to prevent system failure.