Should a Mini Excavator Be Able to Lift Itself Off the Ground

[MikePhua]

Hydraulic Power and Machine Self-Lifting
One of the informal tests often used by operators to assess the hydraulic strength of a mini excavator is whether the machine can lift itself entirely off the ground using its boom and dozer blade. While not a standardized diagnostic method, this maneuver can reveal a lot about the condition of the hydraulic pump, relief valve settings, and overall system pressure.
In theory, a properly functioning mini excavator should be able to raise its tracks off the ground by pushing down with the boom and simultaneously lowering the blade. This action requires the hydraulic system to generate enough force to overcome the machine’s own weight. If it cannot do so, it may indicate weak hydraulics, worn pumps, or improperly set relief valves.
Terminology:

• Relief valve: A hydraulic component that limits system pressure to prevent damage
  
• Breakout force: The maximum force the bucket can exert when digging
  
• Fixed displacement pump: A hydraulic pump that delivers a constant flow rate regardless of load
  
• Merge/divide valve: A valve that controls whether hydraulic flow is combined or split between circuits
  

Factors That Influence Lifting Capability
Several variables affect whether a mini excavator can lift itself:

• Engine RPM: Lower speeds may reduce hydraulic output, making movements sluggish
  
• Pump configuration: Some machines use twin pumps with different pressure ratings for blade and boom
  
• Stick extension: The further the stick is extended, the more leverage is required to lift the machine
  
• Blade position: Stability and lift angle depend on whether the blade is forward or rearward
  
• Valve settings: Relief valves may be set conservatively, limiting available pressure
  

Older machines, such as the 1988 Yanmar YB351, may struggle with this maneuver due to age-related wear or design limitations. Newer models like the Kubota KX series or Takeuchi TB016 often perform better, especially when operated at full throttle.
Operator Technique and Real-World Usage
Experienced operators note that lifting the machine requires finesse. It’s not just about brute force—it’s about coordinating blade pressure, boom angle, and stick movement. Some machines require the boom to be close in to maximize vertical force, while others benefit from a slight stick extension to balance the lift.
In practice, lifting the machine is rarely necessary during normal excavation. However, it can be useful for:

• Cleaning tracks
  
• Expanding or retracting adjustable undercarriages
  
• Navigating over obstacles like garden beds or curbs
  
• Reducing wear during tight turns in sensitive terrain
  

One operator described using the blade and boom to gently place his machine atop a raised garden wall without damaging the structure. Another mentioned lifting one side of the machine to pivot in environmentally sensitive areas, reducing track wear and ground disturbance.
Hydraulic System Design and Limitations
Not all mini excavators are designed with equal hydraulic capacity. Some manufacturers prioritize smooth control over raw power, especially in machines under 2 tons. Others, particularly those built for rental fleets, may have conservative relief settings to reduce wear and prevent abuse.
Design considerations:

• Blade and swing circuits may be powered by a smaller pump
  
• Boom and bucket circuits often have higher pressure ratings
  
• Some machines use fixed displacement pumps, limiting simultaneous function strength
  
• Valve configurations may prioritize one function over another during multi-actuation
  

In one example, a Komatsu PC50 with three fixed displacement pumps could lift itself, but only when boom and blade were used sequentially. The blade’s relief valve would open if both were engaged simultaneously, limiting lift.
When to Be Concerned About Performance
If a mini excavator cannot lift one side of itself using the boom alone, especially when the boom is positioned over the side, it may indicate a deeper issue. Potential causes include:

• Worn hydraulic pump
  
• Internal leakage in cylinders
  
• Low system pressure due to faulty relief valves
  
• Contaminated fluid or clogged filters
  

Before purchasing a used machine, it’s advisable to test hydraulic pressures and inspect for black smoke under load, which may suggest engine strain or fuel system problems. A sluggish response at low RPMs is normal for older machines, but excessive delay or inability to perform basic maneuvers should raise concerns.
Conclusion
While lifting itself off the ground is not a daily requirement for a mini excavator, the ability to do so reflects the health of its hydraulic system and overall design efficiency. Operators should consider this maneuver as one of many informal tests, alongside tracking performance, digging responsiveness, and engine behavior. In compact excavation, power is not just about specs—it’s about how well the machine responds when asked to do something unexpected. And sometimes, lifting itself is the first sign of whether it’s ready to dig deeper.