OPTION AR-LINKAGE 3966802 - Caterpillar

Diverter Valve
Diverter Valve Cutaway - Engine At Low Idle And Machine Is 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 primary steering pump section. (11) Check valve. (12) Supply passage for supplemental 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 diverter valve are: diverter spool (1), check valves (8) and (11) and reversing spool (14).When the engine is running, the oil from the primary 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 primary oil to flow into passage (3).The pressure of the oil before orifice (7) is more than the pressure of the 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 before orifice (7) and to the left end of diverter spool (1) is equal.Oil after orifice (7) flows through passage (6) to the right 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). The oil on the right side of the diverter spool combines with the tension of spring (4) to force the spool to stay shifted to the left.
Diverter Valve Schematic
(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 primary steering pump section. (11) Check valve. (12) Supply passage for supplemental 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 primary steering pump section also increases. Because of 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 the spring on the right end, the diverter spool will shift to the right. This takes place when the engine rpm is 1450 150 rpm.No oil is sent from the supplemental steering pump until the machine moves. When the machine moves, the supplemental steering pump is turned by the output transfer gears in the transmission. Oil from the hydraulic tank is sent to the supplemental pump through supply passage (12). The