FILTER GP-PRIMARY FUEL 7E6719 - Caterpillar

Illustration 1 g00478501
Rear View of Steering Pilot Control Valve and Steering Quad Check Valve
Illustration 2 g03358437
View of Steering Quad Check Valve from left side of machine.The steering quad check valve is located on the upper right side of the non-engine end frame, and near the articulated hitch.The valve consists of four check valves inside a manifold. Two of the check valves have a lower cracking pressure. These check valves are in-line with the flow of oil from the pilot control valve. One check valve with lower cracking pressure is for left turns. One check valve with lower cracking pressure is for right turns.The other two check valves have a higher cracking pressure. These check valves are positioned in a reverse direction. These check valves only unseat when the return pilot oil pressure exceeds a preset value. One check valve with higher cracking pressure is for left turns. One check valve with higher cracking pressure is for right turns.LEFT TURN Position
Illustration 3 g03358634
Schematic of the Steering Quad Check Valve and Associated Components in the LEFT TURN Position (1) Signal line (2) Left steering cylinder (3) Right steering cylinder (4) Return line to the hydraulic oil tank (5) Manifold (orifice and screen) (6) Screen (7) Orifice (8) Steering control valve (9) Pilot oil line for left turns (10) Steering quad check valve (11) Check valve with a higher cracking pressure (12) Left neutralizer valve (13) Check valve with a lower cracking pressure (14) Pilot oil line for right turns (15) Pilot oil line to the hydraulic oil tank (16) Directional spool (17) Hydraulic oil line from the steering pump (18) Secondary pilot pressure line (AA) Pressure tap for checking pilot pressure for left turns at the steering control valve (BB) Pressure tap for checking pilot pressure for right turns at the steering control valveWhen you turn the steering wheel counterclockwise in order to make a left turn, pilot oil flows from the pilot control valve. The pilot oil flows through pilot oil line for left turns (9), and then through check valve (13). The oil then flows through left neutralizer valve (12) .From neutralizer valve (12), the oil flows to a pilot oil chamber in one end of directional spool (16). The pressure of the pilot oil causes directional spool (16) to move left. Any excess pilot oil flows through screen (6) and orifice (7) in manifold (5). The excess pilot oil then flows back to the hydraulic oil tank through return line (4) .When the steering wheel is returned from the LEFT TURN position to the NEUTRAL position, pilot oil flow through pilot oil line (9) will stop. This action will cause check valve (13) to close.The oil between directional spool (16) and check valve (13) will return to the hydraulic oil tank through screen (6) and orifice (7). Screen (6) and orifice (7) are inside manifold (5) .Orifice (7) dampens the