HARNESS AS-CHASSIS 2339935 - Caterpillar

Illustration 1 g01338924
(1) Pilot line (2) Line (3) Line (4) Bucket cylinder (5) Main control valve (6) Return line (7) Center bypass passage (8) Center bypass passage (9) Bucket control valve (10) Spring (11) Orifice (12) Load check valve (13) Spring (14) Negative flow control orifice (15) Pilot control valve (boom and bucket) (16) Parallel feeder passage (17) Return passage (18) Pilot line (19) Negative flow control line (20) Pilot oil manifold (21) Drive pump (22) Idler pump (23) Pilot pumpThe oil delivery for the bucket hydraulic circuit is supplied by drive pump (21) only.
Illustration 2 g00697166
(9) Bucket control valveThe oil delivery from drive pump (21) flows through center bypass passage (8) in main control valve (5) to bucket control valve (9). The oil delivery from idler pump (22) flows through center bypass passage (7) in main control valve (5). Illustration 1 shows the main control valve when only the bucket hydraulic circuit is activated.When the hydraulic lockout lever is in the UNLOCKED position, the oil delivery from pilot pump (23) flows through pilot oil manifold (20) to pilot control valve (15). When the joystick for the bucket is moved to the BUCKET CLOSE position, pilot oil flows through pilot control valve (15) and pilot line (1) to bucket control valve (9). The pilot oil pressure shifts the spool in the bucket control valve against spring (13). The pilot oil on the other end of the spool in the bucket control valve flows