ROD AS-CONNECTING 2019885 - Caterpillar

Illustration 1 g02423757
Pilot control valve
(1) Control lever
(2) Boot
(3) Adjustment screw
(4) Plate
(5) Pushrod
(6) Spring
(7) Spring plate
(8) Return spring
(9) Spring
(10) Control piston
(11) Passage
(12) Pilot control valve
(13) Port "P"
(14) Port "1" (line to control valve)
(15) Port "2" (line to control valve)
(16) Port "T"
Illustration 2 g03724491
Left Console
(1) Control lever
(12) Pilot control valve The pilot control valve (blade and stabilizer) is a directly controlled pressure reducing valve. The valve cartridges are the same control valves that are installed in the pilot control valve (boom and bucket) and the pilot control valve (stick and swing).The control lever of the pilot control valve is held in the neutral position by return springs (8) of the valve cartridges. The neutral position of the valve cartridges can be set via adjustment screws (3) in plate (4) under the boot. In the neutral position, pilot oil is held at port "P" (13). The control piston in this position blocks the oil flow. Passage (11) in piston (10) makes a connection to port "T" (16). This position connects the line at port "2" (15) to the hydraulic tank.When the control lever is moved backward in order to retract the blade and/or the stabilizers, pushrod (5) is moved against the force of return spring (8). The pushrod moves plate (7) against the force of spring (9). Springs (8) and (9) are now compressed and control piston (10) is shifted.Pilot oil in the line that is connected to port "2" (15) can flow through passage (11) in the control piston.The pressure increase is dependent on spring (9). This pressure is kept constant until the lever is activated. The stroke of the control spool in the control valve section depends on the spring force that is acting against the applied pilot pressure to that spool. When the control lever is released, spring (9) returns spring plate (7), spring (9), and control piston (10) to the neutral position. Oil from port "2" (15) is now routed through passage (11) into the return line that is connected to port "T" (16).