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| Illustration 1 | g01287790 |
Neutralizer Valve in the CLOSED Position (1) Inlet port. (2) Ball check valve. (3) Outlet port. (4) Spring for the stem. (5) Stem. | |
The steering neutralizer valves block the flow of pilot oil to the steering control valve. This causes the machine to stop articulating at the end of a complete turn. This occurs before the front of the machine contacts the frame.
The machine is equipped with two steering neutralizer valves, a right valve and a left valve. The neutralizer valves are mounted to the engine end frame. Additionally, there is a right stop assembly and a left stop assembly. The stop assemblies are mounted to the non-engine end frame.
Pilot oil flows from the steering metering pump to either the right neutralizer valve or to the left neutralizer valve through port (1). The pilot oil then flows around stem (5) to port (3). Spring (4) holds stem (5) to the left in the OPEN position. The pilot oil then flows to the steering control valve.
When the machine is turned to the far right, the right stop assembly contacts stem (5) of the right neutralizer valve. This should only occur when the machine is moved to the full RIGHT TURN position and spring (4) is compressed.
As stem (5) moves to the right, the stem blocks the flow of oil through port (1). Because pilot oil cannot flow from port (1) to port (3), no pilot oil can flow to the control valve.
When the flow of pilot oil stops acting on the spool in the steering control valve, the control valve spool returns to the NEUTRAL position. This causes the steering action to stop.
Before steering action can begin, the steering wheel must be turned to the left. This causes pilot oil to flow from the return end of the steering control valve spool to the right neutralizer valve. Because stem (5) is blocking the flow of return oil through the right neutralizer valve, the return oil must flow past ball check valve (2). This allows the steering control valve spool to move back to the CENTERED position, and the machine begins to turn to the left.
As the machine turns to the left, the right stop assembly will move away from stem (5). The force of spring (4) moves stem (5) back to the open position. This allows the return oil from port (3) to flow around stem (5) to port (1), and ball check valve (2) closes.
The left neutralizer valve operates in the same manner as the right neutralizer valve.