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The Volvo L60G Loader and Its Hydraulic Architecture
The Volvo L60G wheel loader was introduced in the early 2010s as part of Volvo Construction Equipment’s G-series, designed to meet Tier 4 emissions standards while improving fuel efficiency and operator comfort. With an operating weight of around 11,000 kg and a breakout force exceeding 100 kN, the L60G is widely used in quarrying, forestry, and municipal work. Volvo CE, founded in 1832 and headquartered in Sweden, has consistently led in hydraulic innovation, and the L60G reflects this with its load-sensing hydraulics and electro-hydraulic controls.
The L60G features a closed-center hydraulic system, meaning oil flow is pressure-regulated and only delivered when demanded. This design improves efficiency and allows for precise control of multiple functions. The machine typically includes a primary joystick for bucket and boom control, integrated transmission buttons, and a secondary lever for third-function hydraulics—used to operate attachments like grapples, shears, or rotary tools.
Understanding the Third Hydraulic Function
The third-function hydraulic circuit on the L60G is configured with two lines for double-acting cylinders or hydraulic motors. It is controlled by a separate lever positioned to the left of the main joystick. This circuit can be used to power attachments requiring bidirectional flow, such as a grapple bucket or rotating broom.
When considering attachments like a tree shear with dual cylinders—one for clamping and one for cutting—the challenge becomes managing two independent hydraulic actions. Many modern shears use electric-over-hydraulic valves mounted directly on the attachment, allowing the operator to control each function via electrical signals rather than separate hydraulic lines.
Integrating Electric Controls with the Loader
To operate such attachments, the third-function circuit can serve as a constant-pressure supply, feeding hydraulic oil to the shear’s onboard valve block. The electric-over-hydraulic system then directs flow to the appropriate cylinder based on joystick or button input. This setup requires:
Terminology Clarification
To ensure compatibility and performance:
A Story from the Field
In Michigan, a forestry crew outfitted their L60G with a tree shear requiring dual-cylinder control. Initially unsure how to manage both functions, they consulted a hydraulic specialist who recommended using the third-function circuit as a supply and integrating electric-over-hydraulic valves. After installing a switch panel and wiring harness, the crew was able to operate clamp and shear functions independently, mimicking skid steer-style control. The modification allowed them to clear over 20 acres of brush in half the expected time.
Conclusion
The Volvo L60G’s third-function hydraulics can be effectively adapted to operate complex attachments like tree shears with dual cylinders. By leveraging electric-over-hydraulic control systems and understanding the loader’s closed-center design, operators can achieve precise, simultaneous control without extensive hydraulic modifications. With proper setup, the L60G becomes a versatile platform for forestry, demolition, and material handling tasks.
The Volvo L60G wheel loader was introduced in the early 2010s as part of Volvo Construction Equipment’s G-series, designed to meet Tier 4 emissions standards while improving fuel efficiency and operator comfort. With an operating weight of around 11,000 kg and a breakout force exceeding 100 kN, the L60G is widely used in quarrying, forestry, and municipal work. Volvo CE, founded in 1832 and headquartered in Sweden, has consistently led in hydraulic innovation, and the L60G reflects this with its load-sensing hydraulics and electro-hydraulic controls.
The L60G features a closed-center hydraulic system, meaning oil flow is pressure-regulated and only delivered when demanded. This design improves efficiency and allows for precise control of multiple functions. The machine typically includes a primary joystick for bucket and boom control, integrated transmission buttons, and a secondary lever for third-function hydraulics—used to operate attachments like grapples, shears, or rotary tools.
Understanding the Third Hydraulic Function
The third-function hydraulic circuit on the L60G is configured with two lines for double-acting cylinders or hydraulic motors. It is controlled by a separate lever positioned to the left of the main joystick. This circuit can be used to power attachments requiring bidirectional flow, such as a grapple bucket or rotating broom.
When considering attachments like a tree shear with dual cylinders—one for clamping and one for cutting—the challenge becomes managing two independent hydraulic actions. Many modern shears use electric-over-hydraulic valves mounted directly on the attachment, allowing the operator to control each function via electrical signals rather than separate hydraulic lines.
Integrating Electric Controls with the Loader
To operate such attachments, the third-function circuit can serve as a constant-pressure supply, feeding hydraulic oil to the shear’s onboard valve block. The electric-over-hydraulic system then directs flow to the appropriate cylinder based on joystick or button input. This setup requires:
- A reliable 12V or 24V power source from the loader
- A switch or joystick interface in the cab
- Wiring harnesses routed to the attachment
- A return line to the loader’s hydraulic tank
Terminology Clarification
- Closed-Center System: A hydraulic design where flow is pressure-regulated and only active when valves are engaged.
- Third Function: An auxiliary hydraulic circuit used to power attachments beyond the standard boom and bucket.
- Electric-Over-Hydraulic Valve: A valve controlled by electrical signals that directs hydraulic flow to specific actuators.
- Double-Acting Cylinder: A hydraulic cylinder that can extend and retract using pressurized fluid on both sides of the piston.
To ensure compatibility and performance:
- Confirm the attachment’s flow and pressure requirements match the loader’s third-function output.
- Use quick couplers rated for the expected pressure and flow.
- Install a cab-mounted switch panel or joystick with momentary toggles for clamp and shear control.
- Protect wiring with conduit and secure routing to avoid pinch points.
- Test the system with the attachment off the ground to verify response and safety.
A Story from the Field
In Michigan, a forestry crew outfitted their L60G with a tree shear requiring dual-cylinder control. Initially unsure how to manage both functions, they consulted a hydraulic specialist who recommended using the third-function circuit as a supply and integrating electric-over-hydraulic valves. After installing a switch panel and wiring harness, the crew was able to operate clamp and shear functions independently, mimicking skid steer-style control. The modification allowed them to clear over 20 acres of brush in half the expected time.
Conclusion
The Volvo L60G’s third-function hydraulics can be effectively adapted to operate complex attachments like tree shears with dual cylinders. By leveraging electric-over-hydraulic control systems and understanding the loader’s closed-center design, operators can achieve precise, simultaneous control without extensive hydraulic modifications. With proper setup, the L60G becomes a versatile platform for forestry, demolition, and material handling tasks.
