VALVE AS 6N7674 - Caterpillar

Illustration 1 g01049420
The steering and brake manifold valve (1) is located on the left side of the machine. The manifold valve is attached to a bracket that is under the front side of the cab.
Illustration 2 g01051344
(A) Port for the pump load sense line (B) Tank port (C) Pump port (D) Supply port to the brush cutter (E) Accumulator portThe steering and brake pump supplies hydraulic oil to the steering and brake manifold valve. The steering and brake manifold valve supplies hydraulic oil to the brake system and the steering system. The manifold valve maintains the pressure in the accumulators at a constant range while the engine is running. An internal relief valve in valve (4) limits the pressure in the steering system. Valve (4) is shown in illustration 3.Accumulators are Charging
Illustration 3 g01049422
Illustration 3 shows the steering and brake manifold valve when the accumulators are charging. When the accumulators are charging, the oil pressure is below the cutout pressure. The pilot unloading spool (1) is shifted to the left, because the accumulator pressure in passage (23) is insufficient to overcome the force of spring (5) and the oil pressure in passage (2). Spool (1) blocks port (3). Port (3) connects to the pump load sense line of the HMU. Supply oil from the steering and brake pump enters through port (14). The supply oil flows into cavity (15) and cavity (28). The oil in cavity (28) contacts piston (29) in the tank relief valve. The oil pressure in cavity (28) does not overcome the pressure of spring (30). Piston (25) does not open.Part of the oil flows through passage (13) to flow through port (12) and passage (11). The oil in port (12) flows to the circuit for the brush cutter in order to keep the circuit filled. The oil in passage (11) flows to cavity (10). The oil in cavity (10) and cavity (15) acts against the oil pressure in chamber (7) and the pressure of spring (6) to establish standby pressure for the circuit.Some of the oil flows through cavity (16) into cavity (19). Some of the oil in cavity (19) flows through dynamic signal orifice (18) into passage (2). Then, the oil flows from passage (17) through a drilled passage that is not shown to passage (8). The oil flows into chamber (7). Oil pressure builds up in chamber (7) and passage (2). Oil pressure acts on both the left and right side of flow control valve (9). Spring (6) shifts flow control valve (9) left. This blocks supply oil in passage (19) from flowing through port (12). This blockage increases the supply pressure. The oil pressure in cavity (19) overcomes the force of spring (22) and the oil pressure behind piston and ball (21). The spring (22) compresses and the piston and ball (21) shift to the left. The supply oil in cavity (19) exits to passage (23) and to the accumulators through port (20) .Accumulators are Charged and the Steering is in Neutral
Illustration 4 g01049563
When the