Used Komatsu 78US-1 Excavator

Reading: 1991

Detailed Introduction to Komatsu 78US-1 Excavator

The Komatsu 78US-1 is a 7-8 ton class ultra-short tail swing mini excavator, first launched by Komatsu in the late 1990s as the first generation of the 78US product line. The "US" suffix in its name stands for Ultra Small Swing, highlighting its core design advantage for narrow-space operations. It is widely favored by small construction teams, rental operators and municipal maintenance teams for its high flexibility, reliability and low operating cost.

1. Core Specifications

Item	Parameter
Operating Weight	7,600 – 8,200 kg (varies by configuration such as bucket size, track width and optional dozer blade)
Engine	Komatsu 4D95LE-2 4-cylinder water-cooled diesel engine, naturally aspirated, meets EU Stage 1 / EPA Tier 1 emission standards
Rated Power	48.5 kW (65 hp) @ 2,200 rpm
Standard Bucket Capacity	0.32 m³, optional range 0.28 – 0.45 m³
Travel Speed	2.8 km/h (low), 4.8 km/h (high)
Swing Speed	11 rpm
Rear Swing Radius	1,380 mm (only 90 mm wider than the standard 450 mm track’s total width of 1,960 mm, almost no overhang outside the track during rotation)
Digging Force	Bucket: 62 kN; Arm: 41 kN
Max. Digging Depth	4,080 mm
Max. Digging Height	7,100 mm
Max. Dumping Height	5,050 mm
Ground Pressure (standard track)	34 kPa

2. Key Standout Features

(1) Industry-leading narrow space adaptability

Its ultra-short tail design eliminates the risk of hitting surrounding obstacles (buildings, vehicles, pipelines) during rotation, making it 30% more efficient than conventional same-tonnage excavators in confined sites. It can even pass through standard 2m-wide building entrances for indoor operations.

(2) Mature and reliable powertrain & hydraulic system

The self-developed 4D95 series engine is famous for its long service life and low failure rate, with an average fuel consumption of only 4-6L per hour, greatly reducing operating costs. It is equipped with Komatsu’s proprietary Closed-center Load Sensing System (CLSS), which delivers precise and smooth compound actions (simultaneous boom lifting, swing and bucket closing) and excellent fine operation performance for precision work such as pipe laying.

(3) Operator-friendly design

The cab is equipped with a shock-absorbing adjustable seat, light-weight pilot control joysticks to reduce long-hour operation fatigue, and a large panoramic front window for unobstructed view of the bucket and working face. Optional ROPS (Roll-Over Protective Structure) is available to improve operation safety.

(4) Easy maintenance

All daily inspection points (oil dipsticks, air filter, fuel filter, oil filter) are arranged at ground-accessible positions, which shortens maintenance time. Komatsu’s global after-sales network and abundant spare parts supply also reduce later maintenance costs.

(5) High versatility

It supports a wide range of attachments, including breaking hammers, wood grabs, augers, quick couplers and grading blades, to adapt to different operation demands. The standard front dozer blade can be used for site leveling, backfilling, and improving machine stability during heavy digging operations.

3. Common Applications

Urban municipal works: Trenching for water/power pipelines, sidewalk renovation, small road maintenance
Landscaping and agriculture: Tree pit digging, irrigation channel excavation, site leveling for gardens
Indoor demolition and renovation: Demolition work inside malls, factories and old buildings, as it can enter narrow doorways and elevators
Confined site construction: Works in old urban areas, narrow mountain roads, and near existing buildings
Waste and recycling sites: Sorting and handling of scattered waste materials

4. Pros & Cons

Advantages

Ultra-small turning radius, unmatched adaptability to narrow sites
Mature powertrain, low failure rate, 10,000+ hours of service life without major overhaul with proper maintenance
Low fuel consumption, high cost performance for small and medium-sized projects
High residual value, strong liquidity in the second-hand equipment market

Disadvantages

As an early-generation model, its emission standard is low, and it cannot enter the core urban areas of most regions with strict emission requirements
Less comfort and intelligent configurations compared to the new generation of 78US series (no on-board diagnostic system, lower cab noise insulation)
Slightly smaller digging depth and height than conventional same-tonnage excavators due to the compact tail design
Aged units may have slight hydraulic oil leakage problems due to seal aging

Final Note

The Komatsu 78US-1 has been discontinued, and its latest successor is the 78US-11 that meets the latest Stage V emission standards. However, well-maintained second-hand 78US-1 units are still very popular in the global market for their high durability and low purchase cost.

Non flooded

No accident

Original product

Used Komatsu 78US-1 Excavator

RELATED PRODUCTS

Komatsu 70-8

Komatsu 78

Komatsu 40

Komatsu 70-8