BRACKET 1957873 - Caterpillar

Hydraulic Control Group
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Hydraulic Control Group (1) Cab floorplate (2) Pedal assembly (3) Pilot control valve (A) LOCKED Position (B) UNLOCKED (SINGLE ACTION) positionThe hydraulic control group is bolted to cab floorplate (1) on the left side of the travel levers/pedal. The hydraulic control group consists of pedal assembly (2) and pilot control valve (3) .To use the single action hydraulic attachment circuit, the pin must be in UNLOCKED position (B) . With the pin in this position, the pedal can be depressed forward and backward. However, the attachment is only supplied hydraulic oil when the pedal is depressed forward. If the single action hydraulic attachment circuit is not needed, the pin should be placed in LOCKED position (A) . When the pin is in the LOCKED position the operator can use the pedal as a foot rest.Operation of Pilot System
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Pilot Oil Lines (3) Pilot control valve (4) Hydraulic activation control valve (5) Main control valve (6) Attachment control valve
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Pilot Control Valve (7) Pilot oil supply port (8) Passage (9) Rod (10) Seat (11) Spring (12) Spring (13) Stem (14) Passage (15) PortWhen hydraulic activation control valve (4) is activated, pilot oil is supplied to port (7) of pilot control valve (3) . The pilot oil at port (7) goes into passage (8) .When pedal (2) is depressed forward, rod (9) and seat (10) are pushed down against the force of springs (11) and (12) . When stem (13) moves down, passage (14) is opened to passage (8) .As passage (14) is opened, the pilot oil in passage (8) goes through passage (14) and then out port (15) . The pilot oil goes to main control valve (5) at the top of attachment control valve (6) .Operation of Front Lines Group
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Front Lines (5) Main control valve (16) Supply line to attachment (17) Return line from attachment (18) Relief valveThe pilot oil pressure moves the attachment valve stem which sends pump oil to the attachment through line (16) . Oil returns from the attachment through line (17) .The oil pressure for the attachment is controlled by relief valve (18) . The pressure setting for the relief valve is 17640 490 kPa (2558.5 71 psi) .Note: The pressure setting for the relief valve must be reset to the specification of the supplier for the attachment that is being used.