CONTROL GP-FOOT BRAKE 1491907 - Caterpillar

HOLD Position
Illustration 1 g03605797
(1) Spool
(2) Passage
(3) Spring In the HOLD position, the spring (3) holds spool (1) in the centered position. The spool (1) blocks the flow of pump supply oil in passage (2).Passage (2) is common to all control valves in the bank valve. The passage has no outlet. The spool blocks the flow of pump supply oil until the operator moves the mechanical Backhoe controls.UP Position
Illustration 2 g03605798
(1) Spool
(2) Passage
(3) Passage
(4) Port for head end
(5) Passage
(6) Load check valve
(7) Passage
(8) Passage
(9) Passage
(10) Port for rod end
(11) Passage
(12) Spring When the stab up circuit is the only hydraulic circuit in operation, the stabilizer circuit will have the highest signal oil pressure in the hydraulic system. When the stabilizer control lever is moved to the stabilizer UP position, spool (1) moves up spring (12) compressed.When the spool moves up, pump supply oil flows from passage (8) around the spool and into passage (7).The signal oil in the internal passage flows to the load check valve in each control valve. The signal oil also flows to the load check valve on the hydraulic pump. The signal oil helps to control the output of the hydraulic pump. The hydraulic pump upstrokes and the hydraulic oil pressure in passage (8) and passage (7) increases. The hydraulic oil flows to passage (9) and passage (5). In passage (5), spool (1) blocks the flow of oil. In passage (9), the oil flows around the spool (1) to passage (11). Then, the oil flows through port (10) to the rod end of the stabilizer cylinder.Hydraulic oil from the head end of the stabilizer cylinder flows to respective stab valves through port (4) to passage (3). The hydraulic oil flows around spool (1) into passages (2).The hydraulic oil in passage (2) flows to all control valves as makeup oil. Then, the hydraulic oil flows to the tank.When the operator releases the stabilizer control lever, spring (12) moves spool (1) to the HOLD position.DOWN Position
Illustration 3 g03605799
(1) Spool
(2) Passage
(3) Passage
(4) Port for head end
(5) Passage
(6) Load check valve
(7) Passage
(8) Passage
(9) Passage
(10) Port for rod end
(11) Passage
(12) Spring When the stab up circuit is the only hydraulic circuit in operation, the stabilizer circuit will have the highest signal oil pressure in the hydraulic system. When the stabilizer control lever is moved to the stabilizer UP position, spool (1) moves up spring (12) compressed.When the spool moves up, pump supply oil flows from passage (8) around the spool and into passage (7).The signal oil in the internal passage flows to the load check valve in each control valve. The signal oil also flows to the load check valve on the hydraulic pump. The signal oil helps to control the output of the hydraulic pump. The hydraulic pump upstrokes and the hydraulic oil pressure in passage (8) and passage (7) increases. The hydraulic oil flows to passage (9) and passage (5). In passage (9), spool (1) blocks the flow of oil. In passage (5), the oil flows around the spool (1) to