TUBE AS 3460759 - Caterpillar

Illustration 1 g00274350
Diverter Valve
(1) Outlet port. (2) Inlet port from primary pump. (3) Check valve. (4) Diverter spool. (5) Check valve. (6) Inlet port for secondary steering pump. (7) Outlet to flow switch. (8) Hydraulic tank return passage. (9) Pressure reducing valve. (10) Relief valve. (11) Spring. (12) Load sense chamber. (13) Load sense inlet port.
The following components are the main components of the diverter valve: diverter spool (4), check valves (3) and (5), relief valve (10) and pressure reducing valve (9).When the engine is running, the oil from the primary pump flows through inlet port (2). The force of the oil opens check valve (5) and oil is allowed to flow out of outlet port (1) to the steering control valve. This oil also holds check valve (3) closed and the oil pushes diverter spool (4) downward. The movement of the spool opens inlet port (6) of the secondary steering pump to hydraulic tank return passage (8). The oil from the secondary steering pump then circulates to the tank.If there is a failure of the primary pump, the pressure behind check valve (3) is reduced. Diverter spool (4) moves up due to the combination of spring force (11) and due to the pressure of the load in load sense chamber (12). This closes the path from inlet port (6) to tank port (8). Oil from the secondary steering pump is forced through check valve (3). This oil then flows to the steering control valve.A failure of the primary steering pump or of associated hydraulic lines is sensed by a flow switch. This flow switch controls a circuit in the operator compartment which alerts the operator of a failure by sending a warning signal to the cab.