Caterpillar Inc.
Caterpillar Cat336 Hydraulic Excavator

Hydraulics System Improves Performance for New Caterpillar Excavator

Aug. 1, 2022
Use of a positive flow electrohydraulic system and larger boom cylinder increase performance and efficiency for the new Cat 336 Hydraulic Excavator.

Caterpillar Inc. has introduced a new version of its Cat 336 Hydraulic Excavator. According to the company, it features a powerful hydraulics system capable of providing strong digging forces and swing torque to maximize productivity for customers. 

In addition, the hydraulics can help to improve fuel efficiency for the machine during some working modes of the engine.  Fuel consumption is also minimized during light load applications due to the use of positive flow control. The hydraulics system of the new excavator features filters with longer lifespans which help to reduce operating costs, as well. 

WATCH and LEARN MORE: The Marriage of Hydraulics and Electromechanical

Hydraulics Make the Difference

Use of a positive flow (open center) electrohydraulic system enabled several benefits to be achieved in the new Cat 336 excavator including improved controllability and efficiency. With this system, valve commands and pump flow are controlled based on joystick commands, and can be adjusted at any time based on working conditions to minimize pressure loss which leads to maximized efficiency, said Jérôme Claret, product and application specialist at Caterpillar Inc., in an interview with Power & Motion

A larger boom/stick/bucket hydraulic cylinder is utilized on the new excavator compared to the previous 336 GC model. "By maximizing the cylinder size, we are maximizing the digging force," explained Claret. "The swing torque has been increased over the 336 GC thanks to high swing relief pressure."

This helps operators to dig more with fewer machine movements, increasing their productivity and efficiency by reducing rework and the number of passes necessary to complete a task. Fuel use can then be reduced as well because the machine is not working as hard or more than required. 

The engine of the new Cat 336 features three modes to meet power demands while enabling opportunities to reduce fuel use. Smart mode is designed to match engine and hydraulic power to digging conditions as a means of lowering fuel consumption stated Caterpillar in its press release announcing the launch of the new 336 excavator.

According to Claret, multiple machine parameters are monitored during Smart mode such as the load factor and lever command. This is done to "assess the power required by the operator and constantly and automatically adjust the engine power to minimize fuel consumption. When maximum power is required, the Smart mode will deliver the maximum power to maximize productivity," he explained. 

Another feature of the new Cat 366 excavator's hydraulics system is the auto hydraulic warmup which can benefit operators working in cold temperatures. If the machine controller within the excavator detects oil temperature has reached a level below what was set by the operator, pump standby flow is automatically increased. "This flow is going through the main valve (center bypass passage, orifices), pilot pressure reducing valve and back to the hydraulic tank," said Claret. "While going through these restrictions, oil is being warmed until the desired temperature is reached." 

This is a valuable functionality for excavator operators as maintaining a proper oil temperature ensures the required viscosity is achieved to properly lubricate moving pieces and maximize efficiency he said.  

Additional design features of the hydraulics system Claret highlighted which benefit the new excavator's performance include: 

  • load enhanced anticipation control which controls fuel injection through the main pump torque;
  • replacement of the traditional pilot gear pump with a pressure reducing valve, enabling pressure to be generated only when needed and therefore reducing energy waste;
  • integrated pilot manifold to minimize lines and connections; and
  • independent electronic pressure reducing valve for boom/stick/swing priority to deliver superior controllability without external valves and hoses.

View more stats on the new Cat 336 Hydraulic Excavator from our colleagues at Construction Equipment magazine.

About the Author

Sara Jensen | Technical Editor, Power & Motion

Sara Jensen is technical editor of Power & Motion, directing expanded coverage into the modern fluid power space, as well as mechatronic and smart technologies. She has over 15 years of publishing experience. Prior to Power & Motion she spent 11 years with a trade publication for engineers of heavy-duty equipment, the last 3 of which were as the editor and brand lead. Over the course of her time in the B2B industry, Sara has gained an extensive knowledge of various heavy-duty equipment industries — including construction, agriculture, mining and on-road trucks —along with the systems and market trends which impact them such as fluid power and electronic motion control technologies. 

You can follow Sara and Power & Motion via the following social media handles:

X (formerly Twitter): @TechnlgyEditor and @PowerMotionTech

LinkedIn: @SaraJensen and @Power&Motion

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