Final answer:
The pressure indicator on a hydraulic pump measures the pressure in psi. Normal operation pressure ranges from 0 to a few hundred psi, while the maximum pressure is the limit that the pump can handle without damage.
Step-by-step explanation:
In the context of hydraulic pumps, the pressure indicator refers to the measurement of pressure in pounds per square inch (psi). The lower and upper limits of normal operation pressure depend on the specific system, but they typically range from 0 to a few hundred psi. The maximum pressure is the highest limit that the pump can handle without causing damage, which can vary depending on the pump's design and specifications.