BUSINESS
07/28/2024

Everything Wrong Mini Excavator and How to Fix It

By Edwin

1. Overheating Cab

Our excavator came with a cab, which we had to remove immediately. The cab would become unbearably hot, making it impossible to operate the machine comfortably. Here’s a detailed look at the issue and our solution:

  • Heat Problem: The cab had a 2-inch gap to the engine compartment, allowing engine heat to blow directly into the cab, making it extremely hot (up to 120°F when it was 85°F outside).
  • Solution: We removed the cab and replaced it with an open ROPS (Roll Over Protection Structure). Although it’s not robust enough to protect in a severe rollover, it’s sufficient to prevent the machine from rolling over onto the operator in case of minor tipping.

2. Engine and Hydraulic Overheating

Straight out of the shipping container, the excavator had severe overheating issues within ten minutes of operation. This caused the hydraulic system to lose power and the machine to become unusable.

  • Original Radiator: The original split radiator (half water, half oil) was inadequate, leading to excessive heat build-up.
  • Solution: We added an external oil cooler in line with the original oil cooler, complete with an electric fan to ensure constant airflow over the oil cooler, even when stationary. This modification maintained the oil temperature at a steady 120°F, which also helped in cooling the engine.

3. Track Issues

Another significant problem was the tracks coming off frequently during operation, especially when turning while tracking.

  • Initial Tensioning: The tracks were not tensioned properly upon arrival.
  • Solution: Properly tensioning the tracks by lifting them off the ground and using hydraulic grease tensioners brought the bottom of the track within half an inch of the bottom roller. To further prevent the tracks from walking off, we modified the rollers:
    • Roller Modification: We added large washers welded onto the front and back rollers to better engage with the track’s groove. This significantly improved the track retention, preventing them from coming off during operation.

4. Auxiliary Hydraulics

The excavator came with one-way auxiliary hydraulics, which is unsuitable for attachments requiring two-way hydraulics, such as a hydraulic thumb.

  • Initial Setup: One-way hydraulics are only good for applications like post hole diggers or concrete breakers.
  • Solution: We added a two-way hydraulic solenoid valve controlled by a switch. This allowed us to convert the one-way system to a two-way system, enabling the operation of a hydraulic thumb.
    • Hydraulic Thumb Installation: We adapted a generic thumb for a 4-ton mini excavator, ensuring it worked with our Quick Connect system. This involved custom welding and modifications to the thumb to fit around the Quick Connect components.

5. Control Enhancements

To manage the new two-way hydraulic system, we had to upgrade the control sticks.

  • Control Stick Upgrade: The original sticks had only one button, so we replaced them with new sticks featuring three buttons for better functionality. This included controls for open and close operations of the hydraulic thumb, enhancing usability and precision.

6. Comfort and Ergonomics

The seat provided with the excavator was uncomfortable, which is a common issue with these imported machines.

  • Solution: We are in the process of sourcing a new, more comfortable seat to replace the original. This is a simple yet effective upgrade to improve operator comfort during long hours of use.