Auxiliary hydraulic flow is used to power a work tool. An example of a work tool that uses one-way flow would be a hammer. The left work tool pedal controls the one-way flow circuit.
If equipped with two-way flow, the left work tool pedal controls the two-way flow circuit. An example of a work tool that uses two-way flow would be a grapple.
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| Illustration 1 | g06015638 |
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Auxiliary Hydraulic schematic (one-way flow) (1) Auxiliary line (2) Return line (3) Main control valve (4) Auxiliary control valve (5) Return passage (6) Parallel feeder passage (7) Center bypass passage (8) Hydraulic pump (9) HPU changeover valve (10) Hydraulic tank | |
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| Illustration 2 | g02471516 |
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One-way flow (1) Auxiliary line (2) Return line (3) Main control valve (4) Auxiliary control valve (11) Work tool pedal | |
Auxiliary control valve (4) has a mechanical linkage which is actuated by work tool pedal (11). When work tool pedal (11) is pushed, auxiliary control valve (4) shifts upward. The pump oil then flows from parallel feeder passage (6) and to line (1). From line (1) the oil flows to the work tool. Return oil from the work tool flows through return line (2) and to hydraulic tank (10).
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| Illustration 3 | g02475428 |
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(A) One-way flow
(B) Two-way flow (12) Work tool flow control lever | |
Note: The work tool flow control lever must be in the two-way flow position.
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| Illustration 4 | g06015661 |
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Auxiliary Hydraulic schematic (two-way flow) (1) Auxiliary line (2) Return line (3) Main control valve (4) Auxiliary control valve (5) Return passage (6) Parallel feeder passage (7) Center bypass passage (8) Hydraulic pump (9) HPU changeover valve (10) Hydraulic tank (12) Work tool flow control lever (13) Auxiliary line | |
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| Illustration 5 | g02471539 |
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Two-way flow (1) Auxiliary line (2) Return line (3) Main control valve (4) Auxiliary control valve (11) Work tool pedal (12) Work tool flow control lever (13) Auxiliary line | |
Auxiliary control valve (4) has a mechanical linkage which is actuated by work tool pedal (11). When work tool pedal (11) is pushed for one-way flow, auxiliary control valve (4) shifts upward. The pump oil then flows from parallel feeder passage (6) and to line (1). From line (1) the oil flows to the work tool. Return oil from the work tool flows through return line (13) and to hydraulic tank (10).
When work tool pedal (11) is pushed for two-way flow, auxiliary control valve (4) shifts downward. The pump oil then flows from parallel feeder passage (6) and to line (13). From line (13) the oil flows to the work tool. Return oil from the work tool flows through return line (1), return passage (5), and to hydraulic tank (10).
Refer to the Systems Operation, "Main Control Valve" for more information on the main control valve and the auxiliary control valve.