Maintaining a 1993 Hitachi EX60 with Nissan Engine Components

[MikePhua]

The Hitachi EX60 and Its Place in Compact Excavator History
The Hitachi EX60 was introduced in the early 1990s as part of Hitachi’s EX series, which helped define the compact excavator category for urban construction, utility trenching, and landscaping. With an operating weight of approximately 13,000 lbs and a dig depth of over 14 feet, the EX60 offered a balance of power and maneuverability that made it popular across Asia, Europe, and North America.
Hitachi Construction Machinery, founded in 1970 as a division of Hitachi Ltd., quickly became a global leader in hydraulic excavator technology. By the time the EX60 was released, Hitachi had already partnered with Fiat and John Deere in various markets, expanding its reach and refining its designs. The EX60 was powered by a Nissan diesel engine, a choice that reflected Hitachi’s strategy of sourcing reliable, serviceable powerplants for its mid-size machines.
Understanding the Nissan Engine in the EX60
The 1993 EX60 typically came equipped with a Nissan BD30 diesel engine—a naturally aspirated, four-cylinder unit known for its simplicity and durability. This engine was widely used in forklifts, small trucks, and industrial equipment throughout the 1980s and 1990s.
Key specifications include:

• Displacement: 3.0 liters
  
• Power output: ~60 horsepower
  
• Fuel system: Inline mechanical injection pump
  
• Cooling: Water-cooled with belt-driven fan
  
• Compression ratio: ~21:1
  

Terminology clarification:

• Inline injection pump: A fuel delivery system where fuel is metered and pressurized in a linear sequence, offering precise timing and easy serviceability.
  
• Naturally aspirated: An engine that relies on atmospheric pressure for air intake, without turbocharging.
  
• Compression ratio: The ratio between the cylinder volume at bottom dead center and top dead center, affecting combustion efficiency.
  

Parts Availability and Cross-Referencing Challenges
One of the main challenges in maintaining a 1993 EX60 is sourcing engine parts. Since the BD30 was used in multiple applications, parts catalogs often list components under automotive or industrial categories rather than construction equipment. This can lead to confusion when ordering filters, gaskets, or injectors.
Solutions include:

• Cross-referencing part numbers with forklift or truck applications
  
• Using Nissan industrial engine catalogs rather than Hitachi-specific manuals
  
• Consulting aftermarket suppliers who specialize in Japanese diesel engines
  
• Verifying dimensions and thread types before ordering replacements
  

A technician in Queensland once sourced a BD30 water pump from a Nissan forklift dealer after discovering that the part number matched across platforms. The pump fit perfectly and cost 40% less than the excavator-specific listing.
Common Wear Items and Maintenance Tips
The BD30 engine is robust but requires regular attention to avoid performance degradation. Common wear items include:

• Fuel injectors: prone to clogging after 2,000–3,000 hours
  
• Glow plugs: essential for cold starts, especially in winter climates
  
• Timing belt: should be inspected every 1,000 hours
  
• Radiator hoses: often overlooked but critical for cooling
  
• Oil seals: especially around the crankshaft and camshaft
  

Maintenance recommendations:

• Change engine oil every 250 hours using 15W-40 diesel-rated lubricant
  
• Replace fuel filters every 500 hours to prevent injector fouling
  
• Flush coolant annually and inspect for corrosion
  
• Use OEM or high-quality aftermarket parts to maintain tolerances
  
• Keep a parts log with cross-referenced numbers for future orders
  

Electrical and Sensor Compatibility
Older Nissan engines like the BD30 use minimal electronics, but some EX60 units may have aftermarket sensors or gauges added over time. Compatibility issues can arise when replacing temperature or oil pressure sensors, especially if the original wiring has been modified.
Tips for resolving sensor issues:

• Use multimeters to verify voltage and resistance before replacement
  
• Match thread pitch and depth when installing new senders
  
• Avoid mixing metric and imperial fittings
  
• Label wires during disassembly to prevent misrouting
  

A contractor in Ontario retrofitted his EX60 with a digital temperature gauge and discovered that the sender required a 10mm fine-thread adapter, which was not included in the kit. After machining a custom bushing, the system worked flawlessly.
Engine Rebuild and Long-Term Viability
If the BD30 engine shows signs of low compression, excessive smoke, or oil consumption, a rebuild may be necessary. Rebuild kits are available through industrial engine suppliers and typically include:

• Pistons and rings
  
• Cylinder liners
  
• Main and rod bearings
  
• Gasket set
  
• Valve train components
  

Rebuilding a BD30 is straightforward for experienced diesel mechanics. The engine’s cast iron block and simple valve train make it ideal for in-shop overhauls. A fleet manager in Indonesia rebuilt three BD30s using locally sourced kits and reported over 5,000 hours of post-rebuild service life.
Conclusion
Maintaining a 1993 Hitachi EX60 with a Nissan BD30 engine is a manageable task with the right approach to parts sourcing and preventive care. While the machine may lack modern diagnostics and emissions systems, its mechanical simplicity and proven design make it a reliable choice for small contractors and owner-operators. By understanding the engine’s origins, cross-referencing parts intelligently, and staying ahead of wear items, operators can keep these legacy machines running strong for years to come.