HOSE AS 2390022 - Caterpillar

Illustration 1 g01209066
(1) Steering solenoid and relief valve The steering solenoid and relief valve is located on the front frame rail under the engine.
Illustration 2 g01211874
Steering solenoid and relief valve
(2) Steering solenoid valve
(3) Passage
(4) Port for the right front steering accumulator
(5) Orifice
(6) Port for right rear steering accumulator
(7) Port for inlet oil
(8) Passage
(9) Port to steering control valve
(10) Cavity
(11) Port for return oil
(12) Cavity
(13) Valve
(14) Setscrew
(15) Spring
(16) Steering relief valve
(17) Return port to steering hydraulic tank
(18) Oil outlets The pressure oil from the steering piston pump is routed through port (7) in order to fill cavity (10). Cavity (10) connects the following components: port (7) from the steering piston pump, ports (4) and (6) for the steering accumulators, port (9) for the steering control valve, passage (3) for steering solenoid valve (2) and steering relief valve (16). Return port (17) drains oil to the steering hydraulic tank. Cavity (12) connects the following components: return port (17), port (11) for return oil from the steering system, passage (3) for steering solenoid valve (2) and steering relief valve (16).Steering Solenoid Valve
Steering solenoid valve (2) is used to drain pressure oil from the accumulators when the machine is not being used.The oil pressure of the steering accumulators is in cavity (10). This oil flows through orifice (5) into passage (3). When the engine start switch is moved to the OFF position, steering solenoid valve (2) is activated. An activated steering solenoid valve (2) allows oil from passage (3) to return port (17) and to the steering hydraulic tank. Orifice (5) controls the rate of pressure that is drained from the accumulators.
Illustration 3 g00490368
Location of electronic control for the steering accumulators
The steering solenoid valve is activated for 70 seconds. The steering solenoid valve is activated by the electronic control for the steering accumulators when the engine start switch key is moved to the OFF position. The electronic control for the steering accumulators is located inside the console that is between the operator seat and the buddy seat. The steering solenoid valve is not activated when the battery disconnect switch or the engine shutdown control is used.Steering Relief Valve
If the accumulator charging valve and the pressure compensator valve fail to destroke the steering piston pump, steering relief valve (16) will protect the steering system. The oil in cavity (10) enters passage (8) in steering relief valve (16). If the pressure of the oil is within limits, valve (13) will block the oil. If oil pressure reaches the relief pressure, valve (13) compresses spring (14). The oil from cavity (10) flows past valve (13) through oil outlets (18). This oil is now open to return port (17) and the oil drains to the steering hydraulic tank.Secondary Steering
The machine does not have a secondary steering pump. An Auxiliary Power Unit can be used in order to operate the steering circuit on a disabled machine. The Auxiliary Power Unit connects to port (5) on the steering solenoid and relief valve and to a suction port on the steering hydraulic