BRACKET 1834277 - Caterpillar

Implement And Travel Operation
Hydraulic Schematic (Partial) (Boom And Travel Activated)
(1) Parallel feeder passage. (2) Main control valves. (3) Stick I control valve. (4) Swing control valve. (5) Left travel control valve. (6) Center bypass passage. (7) Right travel control valve. (8) Heel control valve. (9) Boom I control valve. (10) Center bypass passage. (11) Passage. (12) Passage. (13) Passage. (14) Passage. (15) straight travel control valve. (16) Passage. (17) Passage. (18) Pilot Passage. (19) Pilot passage. (20) Pilot passage. (21) Passage. (22) Passage. (24) Pilot passage. (25) Passage. (26) Parallel feeder passage. (27) Pilot oil manifold. (28) Upper pump. (29) Drain line. (30) Line. (31) Line. (32) Pilot pump. (33) Lower pump. (34) Pilot passage.When the boom control lever is operated during a travel operation, pilot oil from travel and boom pilot control valves goes to right travel control valve (7), left travel control valve (5) and boom I control valve (9), through pilot passages (20), (24) and (34), respectively. When boom I control valve (9) is operated, passage (22) is blocked which increases the pilot oil pressure in pilot passages (18) and (19). The increased pilot pressure activates straight travel control valve (15).Passage (25) connects in series stick I control valve (3), swing control valve (4), boom I control valve (9) and bucket control valve (8). When any of these valves is operated, the connection between passage (25) and passage (13), (14) or (21) is blocked. The pilot oil pressure in passages (18) and (19) increases enough to activate straight travel control valve (15).As long as all of the control levers for stick I control valve (3), swing control valve (4), boom I control valve (9) and bucket control valve (8) are in the NEUTRAL position, pilot passage (18) is open to the pump suction line through passage (25) and drain line (29). The oil pressure in pilot passages (18) and (19) decreases. Straight travel control valve (15) does not activate.When straight travel control valve (15) is activated, oil from upper and lower pumps flows as follows so that the machine can travel straight:1. Oil from upper pump (28) flows through line (30) to passage (17) in main control valves (2). Upper pump oil in passage (17) separates into two flow paths. One path goes through center bypass passage (6) to right travel control valve (7). The other path goes through passage (12), straight travel control valve (15) and center bypass passage (10) to left travel control valve (5). The right and left travel motors now get an equal amount of upper pump oil.2. Oil from lower pump (33) flows through line (31) to passage (16) in main control valve (2). Lower pump oil in passage (16) separates into two flow paths. One path goes through parallel feeder passage (1) to swing control (4) and stick I control (3). The other path goes through passage (11) and straight travel control valve (15) to parallel feeder passage (26). From parallel feeder passage (26), the oil flow separates into