- Pilot oil lines
- Hydraulic control group
- Attachment relief valves
- Upper structure lines
The operation of the main control valve is identical to the standard control lines.
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| Illustration 1 | g00376612 |
(A) SINGLE ACTION position (B) STOP position (C) DOUBLE ACTION position (1) Cab floor (2) Pedal assembly (3) Lock pin (4) Spring pin (5) Pilot control valve | |
The hydraulic control group is bolted to cab floor (1) on the left side of the travel pedal. The hydraulic control group consists of pedal assembly (2) and pilot control valve (5) . The pilot control valve is identical to the travel control valve.
To use the double action system, install pin (3) into DOUBLE ACTION position (C) . Lock pin (3) into position with spring pin (4) . With pin (3) in the DOUBLE ACTION position, the pedal can be depressed forward and backward.
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| Illustration 2 | g00379974 |
Pilot Lines (5) Pilot control valve (6) Hydraulic activation control valve (7) Main control valve | |
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| Illustration 3 | g00379975 |
(8) Pedal (9) Rod (10) Seat (11) Spring (12) Spring (13) Spring (14) Stem (15) Stem (16) Return port (17) Passage (18) Passage (19) Pilot oil supply port (20) Port (21) Passage (22) Passage (23) Port | |
When pedal assembly (2) is depressed forward, pilot oil is sent to main control valve (7) at the top of the attachment control valve. When the pedal assembly is depressed backward, pilot oil is sent to the bottom of the attachment control valve. The pilot oil moves the stem. The stem then sends pump oil to the attachment. Changing the position of the pedal will determine the oil flow to the two-way attachment.
When pedal (8) is rotated forward the pedal pushes down on rod (9) and on seat (10) against the force of springs (11) and (12) . Stem (14) opens passage (17) to passage (22) .
As passage (17) is opened, the pilot oil in passage (22) goes through the following passages: passage (17), the passage in stem (14) and out port (20) . The pilot oil goes to main control valve (7) at the top of the attachment control valve. The pilot oil pressure moves the stem. The stem then sends pump oil to the attachment.
The pilot oil at the bottom of the stem is forced back to the pilot control valve and port (23) . The pilot oil pushes against stem (15) and spring (13) . When the pressure is great enough, stem (15) moves up against the force of spring (13) and passage (18) opens to passage (21) . This allows pilot oil in port (23) to go through the drilled passage in stem (15) and out passage (18) to passage (21) . The pilot oil then flows out of port (16) to the hydraulic activation control valve and to the drain. Spring (13) moves the stem downward. This closes passage (18) to passage (21) when the pilot oil pressure decreases.
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| Illustration 4 | g00380032 |
Front Lines (7) Main control valve (24) Relief valves | |
The same operation occurs when the pedal is rotated in reverse order. The stem in the main control valve is separated into two sections. The bottom of the stem in the main control valve receives pilot oil. The top of the stem is open for draining.
Two line relief valves (24) control the maximum pressure in the attachment circuit when the stem is in the neutral position. The relief valve pressure setting is 31900 ± 1470 kPa (4270 ± 210 psi) .
Note: The relief valve pressure setting must be reset to the proper specification for the attachment that is being used.