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| Illustration 1 | g01061730 |
Oil from the outlet of the steering pump flows to the steering control unit (1) that is located under the instrument panel. The steering control unit consists of the following components:
- relief valve
- anticavitation check valve
- steering control spool
- metering pump
The relief valve limits the maximum pressure that is available to the steering control unit to 13250 ± 2500 kPa (1920 ± 360 psi). The relief valve is set at the factory and the setting is not adjustable. The anticavitation check valve allows the operator to steer the machine when the engine is dead. The steering control spool is a spring centered sleeve type rotary valve. The metering pump is a gerotor type pump. The control spool governs the direction of the turn, while the metering pump controls the rate of the turn.
The steering control unit contains four ports. Oil from the outlet of the steering pump enters the steering control unit through inlet port (2). During the steering of the machine, metered oil flows to the steering cylinder and from the steering cylinder through rod end port (3) and head end port (4). Oil is sent to the charge filter through outlet port (5).