TIP GP-LONG 8J9842 - Caterpillar

Illustration 1 g06268223
Steering neutralizer valves.
(34) Steering neutralizer valves
(A) Turn stops
Illustration 2 g00118089
Steering Neutralizer Valve in the CLOSED Position
(1) Stem
(2) Inlet port
(3) Outlet port
(4) Tank port
(5) 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 (2).Spring (5) holds stem (1) to the left. Oil flows past stem (1) and through outlet port (3). The oil then flows to the steering control valve.When the machine is turned to the far right, the right turn stop contacts stem (1) of the right neutralizer valve. This contact should only occur when the steering wheel is moved to the full RIGHT TURN position and spring (5) is compressed.As the stem moves right, the stem blocks the flow of oil through port (2). Because pilot oil cannot flow from port (2) to port (3), no pilot oil can flow to the steering control valve.When the flow of pilot oil stops acting on the spool in the steering control valve, the spool returns to the NEUTRAL position. This process causes the steering action to stop.When the STIC control is moved back to the left, return oil from the end of the steering control valve spool flows through the line. The return oil then flows into port (3) of the right neutralizer valve. The oil then flows past the stem, through port (4), and back to the hydraulic tank for the steering and brake systems. This process allows the steering control valve spool to move back to CENTERED position, and the machine begins to turn to the left.As the machine moves to the left, the right turn stop will move away from stem (1). The force of spring (5) acts against stem (1). This process causes the stem to move left. As the stem moves left by a small amount, the stem opens port (2). This movement allows pilot oil to flow past the stem and through port (3).The left neutralizer valve operates in the same manner as the right neutralizer valve.