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Overview of the Komatsu PC07-2E
The Komatsu PC07-2E is a compact hydraulic excavator developed in the late 1980s to early 1990s, designed for light-duty excavation, landscaping, and utility trenching. With an operating weight of approximately 1.5 to 1.8 tons, this machine was engineered for maneuverability and ease of maintenance. Its simple, mostly mechanical systems make it a favorite among independent contractors, hobbyists, and rural property owners. Despite its age, many PC07-2E units are still in use globally, particularly in Asia and developing countries where repairability and cost efficiency are paramount.
Engine and Hydraulic System
The PC07-2E is typically powered by a small Komatsu diesel engine—commonly the 2-cylinder Komatsu 2D68E or similar—delivering around 13 to 18 horsepower. This compact engine is mated to a hydraulic pump system that supplies pressure to the boom, arm, bucket, and track drive motors.
The hydraulic system operates on open-center logic, meaning fluid continuously circulates through the system until a control lever directs it to an actuator. The controls are fully mechanical—no electronics or pilot control—using direct-linkage joysticks and levers. This setup ensures that even if the machine suffers electrical failure, its hydraulics can still function as long as the engine runs and fluid pressure is maintained.
Common Issues and Observations
Due to the age of most PC07-2E machines in operation today, wear-and-tear issues are common. Several recurring problems include:
A machine owner in a mountainous region encountered a problem where the track levers would not return to neutral and felt sticky, especially after wet or cold nights. Upon inspection, the return springs were intact, but the lever shafts had corroded inside their bushings. A simple disassembly, polish, and re-greasing restored function. This example illustrates how neglecting basic lubrication on a small machine can quickly lead to frustrating control issues.
Maintenance Recommendations
Keeping a PC07-2E in reliable working condition is entirely feasible, provided preventive maintenance is carried out regularly. Key points include:
One of the main concerns with older models like the PC07-2E is sourcing replacement parts. However, the situation is not dire:
Some owners have upgraded their PC07-2Es with practical modifications to extend usability:
Unique Historical Note
The PC07 series was often used by Japanese municipal services and small agricultural outfits in its early years. It became popular in export markets due to its manageable size and ease of loading onto small trucks or trailers. Many of these units were shipped used to Southeast Asia and Eastern Europe, where they continue to operate in narrow alleys, hillside farms, and small construction sites.
Conclusion
The Komatsu PC07-2E mini excavator stands as a testament to durable, simple engineering. Despite being decades old, it remains useful, repairable, and cost-effective. With routine maintenance and a bit of mechanical know-how, this compact excavator can continue working for years to come. Whether maintained as a working machine or preserved as a historical piece of construction equipment, the PC07-2E continues to earn its place in the legacy of compact earthmoving machinery.
The Komatsu PC07-2E is a compact hydraulic excavator developed in the late 1980s to early 1990s, designed for light-duty excavation, landscaping, and utility trenching. With an operating weight of approximately 1.5 to 1.8 tons, this machine was engineered for maneuverability and ease of maintenance. Its simple, mostly mechanical systems make it a favorite among independent contractors, hobbyists, and rural property owners. Despite its age, many PC07-2E units are still in use globally, particularly in Asia and developing countries where repairability and cost efficiency are paramount.
Engine and Hydraulic System
The PC07-2E is typically powered by a small Komatsu diesel engine—commonly the 2-cylinder Komatsu 2D68E or similar—delivering around 13 to 18 horsepower. This compact engine is mated to a hydraulic pump system that supplies pressure to the boom, arm, bucket, and track drive motors.
The hydraulic system operates on open-center logic, meaning fluid continuously circulates through the system until a control lever directs it to an actuator. The controls are fully mechanical—no electronics or pilot control—using direct-linkage joysticks and levers. This setup ensures that even if the machine suffers electrical failure, its hydraulics can still function as long as the engine runs and fluid pressure is maintained.
Common Issues and Observations
Due to the age of most PC07-2E machines in operation today, wear-and-tear issues are common. Several recurring problems include:
- Hydraulic Drift and Weakness
Cylinders may drift under load, especially the boom and bucket. This is usually caused by worn cylinder seals or internal leakage through spool valves.
- Track Motor Hesitation or Binding
The travel motors may hesitate or “stick,” particularly when cold. This is often due to old hydraulic fluid, sticky control valve linkages, or partial clogging of the case drain line.
- Hard Starting or Fuel Delivery Problems
Aging diesel lines, clogged fuel filters, or weak lift pumps can contribute to hard starting, especially after the unit has been idle for extended periods.
- Electrical Component Decay
Although mostly mechanical, the machine still relies on basic electrical systems for glow plugs, starter motor, and lighting. Faulty wiring, brittle insulation, or corroded connections are common failure points.
- Undercarriage Wear
The rubber tracks, idlers, and sprockets often show heavy wear, especially if the machine was used on abrasive surfaces like gravel or compacted soil.
A machine owner in a mountainous region encountered a problem where the track levers would not return to neutral and felt sticky, especially after wet or cold nights. Upon inspection, the return springs were intact, but the lever shafts had corroded inside their bushings. A simple disassembly, polish, and re-greasing restored function. This example illustrates how neglecting basic lubrication on a small machine can quickly lead to frustrating control issues.
Maintenance Recommendations
Keeping a PC07-2E in reliable working condition is entirely feasible, provided preventive maintenance is carried out regularly. Key points include:
- Engine Oil and Filter
Replace every 100–150 hours with diesel-rated oil (e.g., 15W-40).
- Fuel Filter and Water Separator
Check every 100 hours; replace at least every 200 hours or when contaminated fuel is suspected.
- Hydraulic Fluid and Filter
Use ISO 46 or equivalent hydraulic oil. Change interval varies, but 500–800 hours is standard. If the machine has sat idle for long periods, change it sooner.
- Track Tensioning
Maintain proper track tension with the grease cylinder. Tracks too loose can derail; too tight accelerates wear on sprockets and idlers.
- Cooling System
Clean fins on the radiator and inspect hoses for leaks or brittleness. Overheating in small machines is a common, avoidable issue.
- Battery and Electrical Checks
Keep terminals clean and ensure grounding points are corrosion-free. Glow plug relays should be tested yearly.
One of the main concerns with older models like the PC07-2E is sourcing replacement parts. However, the situation is not dire:
- Hydraulic seals and o-rings are mostly standard and can be matched by measurement at hydraulic shops.
- Engine parts for Komatsu 2D68E are still available in many regions, often through third-party suppliers or rebuild kits.
- Undercarriage components such as rollers and sprockets are harder to source but occasionally found via used parts dealers or online auctions.
- Control cables and linkages can often be custom-fabricated or retrofitted from similar machines.
Some owners have upgraded their PC07-2Es with practical modifications to extend usability:
- LED work lights to replace failing halogen bulbs.
- Auxiliary hydraulic lines added for thumb attachments or small hydraulic breakers.
- Aftermarket seat installations for improved comfort.
- Battery isolators to prevent parasitic drain during long idle periods.
Unique Historical Note
The PC07 series was often used by Japanese municipal services and small agricultural outfits in its early years. It became popular in export markets due to its manageable size and ease of loading onto small trucks or trailers. Many of these units were shipped used to Southeast Asia and Eastern Europe, where they continue to operate in narrow alleys, hillside farms, and small construction sites.
Conclusion
The Komatsu PC07-2E mini excavator stands as a testament to durable, simple engineering. Despite being decades old, it remains useful, repairable, and cost-effective. With routine maintenance and a bit of mechanical know-how, this compact excavator can continue working for years to come. Whether maintained as a working machine or preserved as a historical piece of construction equipment, the PC07-2E continues to earn its place in the legacy of compact earthmoving machinery.
