MODULE-DISPLAY 4382668 - Caterpillar

Illustration 1 g00870380
Diverter valve cutaway (engine at low idle and machine stopped)
(1) Diverter spool
(2) Return passage to hydraulic tank
(3) Passage
(4) Spring
(5) Outlet to steering control valve
(6) Passage
(7) Orifice
(8) Check valve
(9) Passage
(10) Inlet from steering pump
(11) Check valve
(12) Supply passage for secondary steering pump
(13) Spring
(14) Reversing spool
(15) Passage to left end of reversing spool
(16) Passage
(17) Passage
(18) Passage to right end of reversing spool The main components of the secondary steering diverter valve are: diverter spool (1), check valves (8), and reversing spool (14).When the engine is running, the oil from the steering pump flows through inlet (10) and orifice (7) to check valve (8). The force of the oil opens the check valve. The oil flows past the check valve and through outlet (5) to the steering control valve. Check valve (11) will not allow oil to flow to passage (3).The pressure of oil before orifice (7) is more than the pressure of oil after the orifice. These pressures are also felt through passages (9) and (6) respectively.The oil before orifice (7) flows through passage (9) to the left side of diverter spool (1). The pressure of the oil after orifice (7) is the same as the pressure of the oil to the right end of diverter spool (1).
Illustration 2 g00870382
Schematic for the diverter valve
(1) Diverter spool
(2) Return passage to hydraulic tank
(3) Passage
(4) Spring
(5) Outlet to steering control valve
(6) Passage
(7) Orifice
(8) Check valve
(9) Passage
(10) Inlet from steering pump
(11) Check valve
(12) Supply passage for secondary steering pump
(13) Spring
(14) Reversing spool
(15) Passage to left end of reversing spool
(16) Passage
(17) Passage
(18) Passage to right end of reversing spool As the engine rpm increases, the oil flow from the steering pump also increases. Due to the increased oil flow past orifice (7), there is an increase in the difference of the oil pressure before and after the orifice.When the force of the oil on the left end of the diverter spool is more than the combined force of the oil and spring (4) on the right end, diverter spool (1) will move to the right.No oil is sent from the secondary steering pump until the machine moves. When the machines moves, the pump is turned by the output transfer gears in the transmission. Oil from the hydraulic tank is supplied to the secondary pump through supply passage (12). Oil flows from the hydraulic tank through supply passage (12), to reversing spool (14).
Illustration 3 g00870383
Diverter valve cutaway (engine at low idle and machine in forward motion)
(1) Diverter spool
(2) Return passage to hydraulic tank
(3) Passage
(4) Spring
(5) Outlet to steering control valve
(6) Passage
(7) Orifice
(8) Check valve
(9) Passage
(10) Inlet from steering pump
(11) Check valve
(12) Supply passage for secondary steering pump
(13) Spring
(14) Reversing spool
(15) Passage to left end of reversing spool
(16) Passage
(17) Passage
(18) Passage to right end of reversing spool When the machine moves in a forward direction, the secondary steering pump sends pressure oil into passage (17). The pressure of this oil is felt through passage (18) to the right end of reversing spool (14).The force of this oil moves