INDICATOR 1R7049 - Caterpillar

Boom Raise
Illustration 1 g01117747
Boom drift reduction valve BOOM RAISE (1) Passage (2) Port (3) Passage (4) Port (5) Drain line (6) Pilot line (7) Port (8) Passage (9) Passage (10) Valve (11) Passage (12) Spring (13) Spring chamber (14) Passage (15) Passage (16) Spool (17) Boom drift reduction valveWhen the control lever is moved to the BOOM RAISE position, the oil from the control valve (boom I) flows through passage (9) and into boom drift reduction valve (17). The oil acts on the left end face of valve (10). Because no oil is sent to pilot line (6) from the pilot control valve, spool (16) remains stationary. Passage (3) is connected to port (2) through passage (8), passage (15), passage (14) and passage (11) .When passage (3) is connected to port (2), the oil pressure at passage (9) overcomes the force of spring (12). Valve (10) moves to the right side. Spring (12) is compressed. Oil from passage (9) flows through port (2). The oil in spring chamber (13) flows through passages (3), (15), (14) and (11) and into port (2). Oil from passage (9) and spring chamber (13) flows through port (2) and into the head end of the boom cylinders.Boom Lower
Illustration 2 g01117762
Boom drift reduction valve BOOM LOWER (2) Port (3) Passage (4) Port (5) Drain line (6) Pilot line (7) Port (8) Passage (9) Passage (10) Valve (11) Passage (12) Spring (13) Spring chamber (15) Passage (16) Spool (17) Boom drift reduction valve (18) Passage (19) Spring chamber (20) SpringWhen the control lever is moved to the BOOM LOWER position, pilot oil from the pilot control valve flows through pilot line (6). The oil then flows through port (7) and into boom drift reduction valve (17). The oil then moves spool (16) to the left. The oil in spring chamber (13) flows through passage (3), passage (18), passage (15) and passage (8). The oil then flows into spring chamber (19). The oil then flows out of port (4) through drain line (5) to the hydraulic tank. The oil pressure in spring chamber (13) now decreases.Return oil from the head end of the boom cylinders enters boom drift reduction valve (17) through port (2). Because the oil pressure in spring chamber (13) is low, valve (10) begins to open by moving to the right. The return oil now flows through passage (9) and into the control valve (boom I).