HOSE AS 4Z9221 - Caterpillar

Illustration 1 g00814857
Hydraulic Schematic for Steering Systems that use Metering Pumps (1) Steering metering pump (2) Neutralizer valve for a left turn (3) Left turn stop. (4) Neutralizer valve for a right turn (5) Right turn stop. (6) Steering control valve (7) Selector spool (8) Directional spool (9) Crossover relief valve for the steering cylinders (10) Left steering cylinder (11) Right steering cylinder (12) Signal line (13) Steering pump (14) Flow control orifice (15) Breaker relief valve (16) Relief valve for the case drain for the steering pump (17) Hydraulic oil tank (AA) Pressure tap for checking steering pump pressure (BB) Pressure tap for checking signal pressure
Illustration 2 g01213769
Right Side ViewSteering Components (1) Metering pump. (2) Neutralizer valve for a left turn. (3) Left turn stop. (4) Neutralizer valve for a right turn. (5) Right turn stop. (6) Steering control valve. (11) Right steering cylinder. (13) Steering pump. (17) Hydraulic oil tank. (AA) Pressure tap for checking steering pump pressure. (BB) Pressure tap for checking signal pressure.
Illustration 3 g01213778
Left Side ViewSteering Components (10) Left steering cylinder.The primary steering system is made up of two basic circuits. The two basic circuits are the pilot circuit and the high pressure circuit. When a machine is equipped with the secondary steering attachment, the steering system includes one additional circuit.Metering pump (1) is attached to the bottom of the steering column, and located under the floor of the operator's compartment. Neutralizer valves (2) and (4) are located on the front center section of the upper frame. The neutralizer valves are also located under the operator's compartment and near the upper hitch.Steering control valve (6) is located on the right side of the machine under the operator's platform. Steering control valve (6) is also located above hydraulic oil tank (17). Hydraulic oil tank (17) is located on the right side of the machine.Steering pump (13) is located under the operator's cab on the right side of the machine. A pressure and flow compensator valve is attached to steering pump (13) .Pilot Circuit
The pilot circuit consists of the following components. Metering pump (1), neutralizer valve for a left turn (2), neutralizer valve for a right turn (4), selector spool (7), directional spool (8), steering pump (13), flow control orifice (14) and hydraulic oil tank (17) .The pilot system controls the movement of selector spool (7) and directional spool (8) in steering control valve (6) .Steering pump (13) draws oil from hydraulic oil tank (17). Pressure oil from steering pump (13) flows to steering control valve (6). The oil then flows through flow control orifice (14). Flow control orifice (14) reduces the amount of oil flow to metering pump (1) .Metering pump (1) is a small hydraulic pump that is used as a metering valve and as a directional control valve. When the operator turns the steering wheel, a spool and a sleeve rotates inside the metering pump. This