Which of the following statements about a hydraulic elevator system is not true?

Counterweights are a feature of traction elevators, not hydraulic elevators. In hydraulic elevator systems, the operation relies on a hydraulic fluid mechanism. The elevator cab is raised and lowered using a piston pushed by hydraulic fluid, rather than utilizing counterweights to balance the weight of the cab.

The other statements reflect true characteristics of hydraulic elevators. The hydraulic system indeed functions through the movement of fluid, which is fundamental to its operation. Periodic maintenance is essential for all types of elevators, including hydraulic systems, to ensure safety and reliability, as wear and tear can pose risks if not properly maintained. Energy efficiency comparisons generally favor traction elevators over hydraulic systems due to the latter's energy consumption, especially for moving heavier loads over greater distances.