HLD350 MK2 and HLD2000 MK2 are hydraulic linear drives designed for boats with mechanical steering systems such as wire and cable steering (Edson, Whitlock, Teleflex).
The HLD is a compact, assembled unit, consisting of a reversible hydraulic pump, a balanced hydraulic cylinder, by-pass valve and oil tank. Because of the direct connection to the rudder, the hydraulic linear drive can be used even if the hand steering should fail. This can be an important safety factor.
The by-pass valve makes it possible to use the helm with little back drive force when the autopilot is switched off. The HLD350 MK2 and HLD2000 MK2L supersede the previous HLD350 and HLD2000L models. This manual also includes HLD2000 MK2D. This model is based on the same main parts as HLD350 MK2, but uses the HLD2000 MK2LD motor.