 | |
| Illustration 1 | g01183238 |
Partial hydraulic schematic for swing boom (1) Swing boom cylinder (2) Control valve for the swing boom (3) Center bypass passage (4) Load check valve (5) Main control valve (6) Swing pump | |
The swing boom is used to dig in locations that prevent the upper structure from swinging. The main components of the swing boom are listed below.
- Joystick slide control
- Solenoid valve group for boom swing
- Main control valve
- Control valve for the swing boom
- Swing boom cylinder
 | |
| Illustration 2 | g01183257 |
Cab floor (7) Foot pedal for the swing boom | |
When the foot pedal for the swing boom (7) is moved from the center position, oil will be supplied to the hydraulic system of the swing boom.
Moving the foot pedal for the swing boom to the left allows pump oil to flow to the head end of the swing boom cylinder. This causes the swing boom to swing left. Moving the foot pedal for the swing boom to the right allows pump oil to flow to the rod end of the swing boom cylinder. This causes the swing boom to swing right.
 | |
| Illustration 3 | g01183371 |
(1) Foot pedal for the swing boom (2) Rod (3) Lever (4) Cable (5) Main control valve | |
When the foot pedal for the swing boom (1) is depressed to the right, rod (2) presses on lever (3). The lever rotates counterclockwise pulling cable (4). Cable (4) is connected to the spool valve for boom swing.
The shifted spool allows pump oil to flow to the swing boom.
The same operation happens in reverse order when the foot pedal for the swing boom (1) is depressed to the left.
 | |
| Illustration 4 | g01183489 |
Front lines of swing boom (1) Line (head end) (2) Main control valve (3) Line (rod end) (4) Cylinder (5) Swing boom | |
Swing Left
Supply oil flows from the main pump to the main control valve. When the foot pedal for the swing boom is pressed to the RIGHT, the boom swing control valve directs main pump oil to the head end of the cylinder through line (3). Return oil flows out of the rod end of the cylinder, through line (1), and back through the main control valve.
Swing Right
Supply oil flows from the main pump to the main control valve. When the foot pedal for the swing boom is pressed to the LEFT, the boom swing control valve directs main pump oil to the rod end of the cylinder through line (1). Return oil flows out of the head end of the cylinder, through line (3), and back through the main control valve.