In brief
ZF's Conventional Steering Gear description includes relief valves limiting hydraulic pressure. This protects the system rather than providing an arbitrary assistance boost.
Useful to know
ZF's Conventional Steering Gear description includes relief valves limiting hydraulic pressure. This protects the system rather than providing an arbitrary assistance boost. [1]
Pressure being present does not establish correct operation. Diagnosis requires specified values and conditions; higher pressure does not automatically mean better or safer steering.
Sources
For further detail and to check the information: