HOSE AS 2597144 - Caterpillar

Steering Oil Circuit
Steering Hydraulic System Schematic.
(1) Oil cooler. (2) Metering pump (steering). (3) Left neutralizer valve. (4) Left steering cylinder. (5) Right steering cylinder. (6) Steering control valve. (7) Orifice. (8) Valve spool. (9) Pilot section of pump. (10) Implement section of pump. (11) Steering section of pump. (12) Pump group. (13) Filter group. (14) Hydraulic tank group. (15) Pressure reducing valve. (16) Right neutralizer valve. (A) To implement system. (B) To brake system. (C) To implement pilot system.With the engine running, oil flows from hydraulic tank (14) to pump group (12). The three section vane pump has individual pump sections for the steering circuit, implement circuits and pilot circuits.The steering pump sends the oil to steering control valve (6). Oil flows through valve spool (8) in steering control valve (6) to steering cylinders (4) and (5). The oil returning from the cylinders flows through the control valve to oil cooler (1). Then the oil flows through oil cooler (1) and returns to the hydraulic tank.Bypass orifice (7) allows a small amount of oil to flow from the control valve, around the oil cooler, to the hydraulic tank.Under normal operating oil temperature, most of the oil flows through oil cooler (1) and back to hydraulic tank (14).Steering Control Valve
Neutral Position
Steering Control Valve In Neutral
(1) Metering orifices. (2) Passage. (3) Passage. (4) Outlet for left turn. (5) Outlet to tank. (6) Outlet for right turn. (7) Metering orifices. (8) Spring. (9) Inlet (from right neutralizer valve). (10) Inlet (from left neutralizer valve). (11) Orifice. (12) Spool. (13) Return passage. (14) Passage. (15) Inlet (from steering pump section). (16) Ball resolver valve. (17) Passage. (18) Flow control valve. (19) Relief valve. (AA) Pressure Oil. (BB) Return Oil. (CC) Blocked Oil.The flow of pilot oil to either end of valve spool (12) is stopped when; (a) rotation of steering wheel is stopped, or (b) the neutralizer valve stops the flow after a complete turn has been made. With no pilot oil flow against either end of the valve spool, spring (8) will keep the spool in its neutral position.When the steering control valve is in its neutral position no pilot oil flows to either inlet (9) or (10). Spring (8) centers spool (12) and blocks the oil flowing from the steering pump.Because the oil is blocked by the spool, oil pressure increases in inlet passage (15). This pressure increase causes flow control valve (18) to move to the right. When the flow control valve moves, oil can flow through the orifices in it to outlet (5).When the valve spool is in the neutral position, it also blocks the oil in the lines to the cylinders. This holds the machine in the turning radius it was in when steering wheel movement was stopped.The pressure of the oil in blocked outlet (4) or (6) is felt through ball resolver valve (16) and against pilot relief valve (19). If an outside force tries to turn the machine when the valve spool is in the