Case 280, 330, 380, 430, 480, 530 Steiger Tractor Service Manual

Table of Contents

• General
• Engine
• Electrical
• Steering
• Power Train
• Brakes
• Hydraulics
• Chassis
• Controllers
• Electrical Schematic
• Hydraulic Schematic

Manual Extract: ELECTROHYDRAULIC STEERING SYSTEM (EHPS)

When equipped with the electrical actuation module (PVE), the system steering can be controlled by a hydraulic signal from the steering hand pump or by an electrical signal through the electrical actuation module.

When manually steering, the steering hand pump controls the delivery of pilot pressure/flow to the EHPS directional control valve spool. The steering hand pump pilot pressure is limited to 450 PSI (30 Bar). As the steering hand pump is turned left, the pilot flow is directed out the “L” port of the steering hand pump, which shifts the steering valve directional control spool to the right. Once the directional spool shifts, the PFC piston pump supplies the flow to extend/retract the cylinders and steer left.

As the steering hand pump is turned right, the pilot flow is directed out the “R” port of the steering hand pump, which shifts the steering control directional control spool to the left. Once the directional spool shifts, the PFC piston pump flow supplies the flow to extend/retract the cylinders and steer right.

The steering hand pump has priority over the electrical actuation module. Even when in an auto steering mode, the operator has the ability to take over the steering manually.