SWITCH ASSEM. 6A9535 - Caterpillar

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Back up relief valve for the steering system
The backup relief valve is located on the upper right rear on the steering control valve as you face the right side of the machine.
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Schematic for the Steering Control Valve
Back up Relief Valve for the Steering System
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Back up Relief Valve for the Steering System
(68) Screw
(69) Jam nut
(70) Spring chamber
(71) Spring
(72) Outlet hole to the hydraulic oil tank
(73) Outlet hole
(74) Inlet hole from the steering pump
(75) Valve seat
(76) Poppet for the relief valve
(77) Drain hole
(78) Drain hole
(79) Annular facePressure may suddenly increase due to steering resistance. The load control of the steering pump may not regulate the pump output at a fast enough rate. If this situation occurs, the backup relief valve connects the inlet passage of the steering control valve to the hydraulic oil tank.Spring (71) holds steering relief valve poppet (76) against valve seat (75).Steering pump pressure is sensed in the backup relief valve through holes (74). This pressure acts on annular face (79).If the pressure acting on annular face (79) exceeds the pressure setting on the backup relief valve, poppet (76) moves left against spring (71).Pressure is then relieved to the hydraulic oil tank through outlet holes (72) and (73).Drain holes (77) and (78) connect spring chamber (70) to the hydraulic oil tank.The pressure setting of the backup relief valve for the steering system is adjustable.Reference: For additional information on the adjustment procedure for the backup relief valve, refer to the Service Manual module for Testing and Adjusting, "950L Wheel Loader and 962L Wheel Loader", "Steering Control Valve Pump Pressure Backup Relief Valve - Test and Adjust".Steering Neutralizer Valve
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Steering Neutralizer Valve in the CLOSED Position
(80) Stem
(81) Inlet port
(82) Outlet port
(83) Tank port
(84) SpringThe steering neutralizer valves block the flow of pilot oil to the steering control valve. This process causes the machine to stop articulating at the end of a complete turn. The machine stops articulating just before the loader frame contacts the engine end frame.A left turn stop is used for the steering neutralizer valve for a left turn. A right turn stop is used for the steering neutralizer valve for a right turn. Both the left turn stop and the right turn stop are mounted on the non-engine end frame. Both of the neutralizer valves are mounted on the engine end frame. Both the right neutralizer valve and the left neutralizer valve are identical. Additionally, both the right turn stop and the left turn stop are identical.Pilot oil flows from the steering pilot valve to either the right neutralizer valve or to the left neutralizer valve. This process happens before the oil flows to the steering control valve. Oil flows from the steering pilot valve into the neutralizer valve through inlet port (81).Spring (84) holds stem (80) to the left. Oil flows past stem (80) and through outlet port (82). The oil then flows to the steering control valve.When the machine is turned to the far right, the right turn stop contacts stem