Heavy Duty Power Steering Systems

The hydraulic power steering systems used on trucks today are basic systems. A pump provides a movement of fluid through a system at a measured rate. The activation of valves to divert the flow by turning the steering wheel causes the fluid, which is non-compressible, to create pressure that is then used to move the piston in the steering box. This causes the sector shaft to turn and through the pitman and steering arm, turns the wheels.

Power steering pumps provide a flow of non-compressible fluid at a constant measured rate. Valves in the system, either in a control valve on the drag link or within the steering gear box itself, direct the flow through areas of restriction. This creates pressure since the volume of flow remains the same. The pressure created is used to push internal components or sometimes external rams to assist in moving the wheels one way or the other. The most important component in the system is the fluid. The fluid used should always be the manufacturer’s approved specifications for the system. (See fluid recommendations) The rest of the system is designed to move and contain the fluid. This is the Pump, reservoir, hoses, gear box and valves. These components are designed to work as a system and must be matched to function properly.