BUSHING G 4K4080 - Caterpillar

Illustration 1 g00909501
Joystick control lever (1) Joystick control lever (2) CoverJoystick control lever (1) controls the implement functions. The pilot control valve is located behind cover (2).
Illustration 2 g00909503
Pilot control valve (1) Joystick control lever (3) Line (implement function 1) (4) Pilot control valve (5) Line (implement function 1) (6) Line (drain) (7) Line (implement function 2) (8) Line (implement function 2) (9) Line (pilot oil)
Illustration 3 g00909509
Pilot control valve (1) Joystick control lever (3) Line (implement function 1) (5) Line (implement function 1) (7) Line (implement function 2) (8) Line (implement function 2) (9) Line (pilot oil) (10) Joint (11) Plate (12) Rod (13) Rod (14) Seat (15) Metering spring (16) Return spring (17) Return chamber (18) Return passage (19) Return passage (20) Passage (21) Passage (22) Spool (23) Spool (24) Passage (pilot oil supply)Joystick control lever (1) pivots on joint (10). When joystick control lever (1) is moved to the left, plate (11) tilts to the left. Plate (11) pushes down on rod (13) and seat (14). Seat (14) pushes against the force of metering spring (15) and spring (16). The force of metering spring (15) moves spool (23) down opening passage (21). Oil now flows through passage (24) and passage (21) to line (3) or line (8). The oil flows from line (3) or line (8) to the main control valve. The pressure of the oil on the ends of the main control valve spool causes the main control valve spool to move for an implement operation.The oil at the opposite end of the main control valve spool flows back through line (5) or line (7). The oil flows through return passage (19) and into return chamber (17). The oil flows back to the hydraulic tank from return chamber (17) .When rod (12) is not pushed down, return passage (19) is open and passage (20) is closed.When the joystick control lever is released, spring (16) returns the joystick control lever to the NEUTRAL position.Modulated Pilot Pressure
Illustration 4 g00515381
Partial cross section of the pilot control valvePassage (21) is open and return passage (18) is closed. (13) Rod (14) Seat (15) Metering spring (16) Return spring (18) Return passage (21) Passage (23) Spool (24) Passage (pilot oil supply) (25) Passage (A) Shoulder (B) Shoulder
Illustration 5 g00515383
Partial cross section of the pilot control valvePassage (21) is closed and return passage (18) is open. (18) Return passage (21) Passage (23) Spool (25) Passage
Illustration 6 g00515382
Partial cross section of the pilot control valvePassage (21) is closed and return passage (18) is closed. (13) Rod (15) Metering spring (18) Return passage (21) Passage (23) Spool (25) PassageAs joystick control lever (1) is moved to the left, rod (13) moves seat (14) which compresses metering spring (15). Compressing metering spring (15) moves spool (23) downward. Movement of spool (23) against metering spring (15) controls the pressure of the pilot oil that goes through passage (21) to the main control valve. This allows modulation of pilot pressure to the spool of the main control valve. Modulation of pilot pressure