MACHINE AR 3230337 - Caterpillar

Illustration 1 g00886796
Hydraulic Schematic for Swing Boom (1) Swing cylinder (2) Line (head end of swing boom cylinder) (3) Line (rod end of swing boom cylinder) (4) Swing boom control valve (5) Pilot line (swing left) (6) Main relief valve for swing boom and blade (7) Return line (8) Pilot line (swing right) (9) Pilot supply line (10) Pilot control valve (11) Pilot manifold (12) Return line (13) Pilot supply line (14) Line (supply oil from swing boom pump) (15) Pilot pump (16) Pilot supply line from pilot pump (17) Return line (18) Hydraulic tank (19) Swing boom pump (20) Load check valve (21) Manifold (22) Center bypass passage (23) Return passageThe swing boom is used to dig in locations that prevent the upper structure from swinging. The main components of the swing boom are listed below.
Pedal
Pilot control valve
Main control valve
Swing boom control valve
Swing boom cylinder
Illustration 2 g00842086
Control pedal for swing boom (24) Control pedal (25) FootrestUnder the right footrest, the hydraulic control is bolted to the cab floorplate on the right side of the travel levers/pedals. The hydraulic control consists of control pedal (24) and the pilot control valve (10) below the control pedal.Only when the pedal is depressed, the hydraulic system of the swing boom is supplied with oil.Depressing the pedal to the left allows pump oil to flow to the head end of the swing boom cylinder. This causes the swing boom to swing left. Depressing the pedal to the right allows pump oil to flow to the rod end of the swing boom cylinder. This causes the swing boom to swing right.
Illustration 3 g00842064
Control Pedal and Pilot Control Valve (24) Control pedal (26) Rod (27) Seat (28) Spring (29) Spring (30) Port (return oil to hydraulic tank) (31) Stem (32) Passage (33) Passage (34) Port (pilot oil pressure) (35) Port (36) Port (37) Passage (38) Passage (39) Passage (40) Stem (41) SpringWhen pedal (24) is depressed to the right, the pedal pushes down on rod (26) and seat (27) against the force of spring (28) and spring (29). Stem (31) is moved downward, and the stem opens passage (37) to passage (32) .As passage (37) is opened, pilot oil from port (34) flows through passage (32) and through a drilled passage in the stem (33). The oil leaves through port (35). The oil enters the swing boom control valve. The pilot oil then shifts the spool in the swing boom control valve.The shifted spool allows pump oil to flow to the swing boom. The spool also forces the pilot oil at the front of the swing boom control valve to flow back to the pilot control valve and to port (36). The pilot oil pushes up on stem (40) and spring (41). When the pressure is high enough, stem (40) moves up against the force of spring (41), and passage (38) opens