Small excavator

PC78US-11

  • Horsepower 51 kW @ 1 850 rpm 68 HP @ 1,850 rpm
  • Operating weight 7 910 - 8 250 kg 17,438 - 18,188 lbs.
  • Bucket capacity 0.09 - 0.20 m3 0.12 - 0.26 yd3

When you need compact versatility

Designed to excel in underground utility and general construction in urban environments, this new Komatsu short tail swing excavator is at home in confined spaces. Extremely transportable, it delivers high attachment flow with in-cab programmable flow rates for a wide range of attachments.

  • Compact design works in confined areas
  • Accepts a wide range of attachments
  • Easy to transport
  • Uses up to 13% less fuel than prior model

Features and benefits

Overhead diagram of Komatsu PC78 excavator turning radius

Compact design

For working in tight areas, a compact short tail swing offers maneuverability in more confined areas than a conventional excavator, such as in a single lane of traffic. The conventional boom design has a greater raising angle to reduce the front bucket swing radius.
Working mode for Komatsu excavators

Fast cycles and custom modes

Faster boom up/swing speed, combined with responsive quick arm speed, makes excavating and leveling work easier and more efficient over previous models. Six working modes let you tailor the machine to the tasks required, whether it be for performance or fuel savings.
Komatsu PC78 excavator

Versatility and efficiency come standard

Standard high flow auxiliary hydraulics with proportional joysticks allows you incredible job versatility while providing precise attachment control. Standard grading blade with new moldboard profile improves backfilling and light grading efficiency over previous models.
Operator view from Komatsu PC78 excavator

Maximum operator comfort

Operators work comfortably in a quiet, climate-controlled cab featuring air suspension seat, Bluetooth radio, and high-resolution monitor with rearview camera. LED lights provide excellent vision at night. Sliding cab door makes entry and exit easier in confined spaces.
Looking down at Komatsu PC78 excavator on job site

Fuel efficient, low-cost power

The new high-efficiency power package and viscous fan clutch work together to lower overall fuel consumption up to 13%*. A smart, simplified catalytic system removes soot without a diesel particulate filter, meaning lower cost of ownership and less maintenance.
Operator working on Komatsu PC78 excavator

Quick and easy maintenance

Periodic maintenance is more accessible and efficient with large service access doors and grouped service points with ground-level access.

Specifications for PC78US-11

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US system Metric
Engine
Model Komatsu SAA3D95E-1*
Type Water-cooled, 4-cycle, direct injection
Aspiration Turbocharged, aftercooled, cooled EGR
Number of Cylinders 3
Bore 95 mm
Stroke 115 mm
Piston displacement 2.45 L
Horsepower @ 1 900 rpm:  
    SAE J1995 / Gross 50.7 kW
    ISO 9249 / SAE J1349 / Net 50.7 kW
    Rated rpm 1 850
Fan drive method for radiator cooling Mechanical with viscous fan clutch
Governor All-speed control, electronic

*EPA Tier 4 Final emissions certified

Model Komatsu SAA3D95E-1*
Type Water-cooled, 4-cycle, direct injection
Aspiration Turbocharged, aftercooled, cooled EGR
Number of Cylinders 3
Bore 3.74 in
Stroke 4.52 in
Piston displacement 149.5 in3
Horsepower @ 1,900 rpm:  
    SAE J1995 / Gross 68.0 HP
    ISO 9249 / SAE J1349 / Net 67.9 HP
    Rated rpm 1,850
Fan drive method for radiator cooling Mechanical with viscous fan clutch
Governor All-speed control, electronic

*EPA Tier 4 Final emissions certified

Hydraulics

HydrauMind (Hydraulic Mechanical Intelligence New Design) system, closed-center system with load-sensing valves and pressure-compensated valves

Number of selectable working modes  
Main pumps:  
    Pumps for Boom, arm, bucket, swing, and travel circuits
    Type Variable displacement, axial piston
    Maximum flow 168 L/min
    Pumps for Blade
    Type Fixed displacement gear
    Maximum flow 63 L/min
Hydraulic motors:  
    Travel 2 x piston motor with parking brake
    Swing 1 x axial piston motor with swing holding brake
Relief valve setting:  
    Implement circuits 29.4 MPa 300 kgf/cm2
    Travel circuits 29.9 MPa 305 kgf/cm2
    Swing circuit 21.9 MPa 223 kgf/cm2
    Pilot circuit 3.2 MPa 33 kgf/cm2
    Blade circuit (Raise) 12.3 MPa 125 kgf/cm2
    Blade circuit (Lower) 21.1 MPa 215 kgf/cm2
Hydraulic cylinders (Number of cylinders): bore x stroke x rod
    Boom (2) 110 x 858 x 65 mm
    Arm (1) 95 x 861 x 60 mm
    Bucket (1) 85 x 710 x 55 mm
    Blade (1) 130 x 130 x 65 mm
Auxiliary hydraulics (two-stage relief):  
    Two-way 138 L/min
    Relief 26.51 MPa
    One-way 80 L/min
    Relief in breaker mode 17.17 MPa

HydrauMind (Hydraulic Mechanical Intelligence New Design) system, closed-center system with load-sensing valves and pressure-compensated valves

Number of selectable working modes 6
Main pumps:  
    Pumps for Boom, arm, bucket, swing, and travel circuits
    Type Variable displacement, axial piston
    Maximum flow 44.4 gpm
    Pumps for Blade
    Type Fixed displacement gear
    Maximum flow 17.0 gpm
Hydraulic motors:  
    Travel 2 x piston motor with parking brake
    Swing 1 x axial piston motor with swing holding brake
Relief valve setting:  
    Implement circuits 4,264 psi
    Travel circuits 4,337 psi
    Swing circuit 3,176 psi
    Pilot circuit 464 psi
    Blade circuit (Raise) 1,784 psi
    Blade circuit (Lower) 3,060 psi
Hydraulic cylinders (Number of cylinders): bore x stroke x rod
    Boom (1) 4.33 x 33.8 x 2.56 in
    Arm (1) 3.74 x 33.9 x 2.36 in
    Bucket (1) 3.35 x 27.95 x 2.17 in
    Blade (1) 5.12 x 5.12 x 2.56 in
Auxiliary hydraulics (two-stage relief):  
    Two-way 36.5 gpm
    Relief 3,830 psi
    One-way 21.1 gpm
    Relief in breaker mode 2,490 psi
Drives and brakes
Steering control     Two levers with pedals
Drive method Hydrostatic
Maximum drawbar pull 68.1 kN 6820 kgf
Maximum travel speed:  
    High 5 kph
    Low 2.7 kph
Service brake Hydraulic lock
Parking brake  Mechanical discs 
Steering control     Two levers with pedals
Drive method Hydrostatic
Maximum drawbar pull 15,309 lbf.
Maximum travel speed:  
    High 3.1 mph
    Low 1.9 mph
Service brake Hydraulic lock
Parking brake  Mechanical discs 
Swing system
Driven by  Hydraulic motor 
Swing reduction
Planetary gear
Swing circle lubrication  Grease-bathed 
Swing lock  Mechanical disc brake
Swing speed 10 rpm
Driven by  Hydraulic motor 
Swing reduction
Planetary gear
Swing circle lubrication  Grease-bathed 
Swing lock  Mechanical disc brake
Swing speed 10 rpm
Undercarriage
Center frame  X-frame leg
Track frame  Box-section 
Track type Sealed
Track adjuster  Hydraulic 
Number of shoes
39 each side
Number of carrier rollers       1 each side 
Number of track rollers
5 each side 
Center frame  X-frame leg
Track frame  Box-section 
Track type Sealed
Track adjuster  Hydraulic 
Number of shoes
39 each side
Number of carrier rollers       1 each side 
Number of track rollers
5 each side 
Coolant and lubricant capacity (refilling)
Fuel tank 125 L
Radiator  18 L
Engine 10.5 L
Final drive, each side 1.1 L
Swing drive 2.0 L
Hydraulic tank  56 L
Fuel tank 33.0 US gal
Radiator  4.8 US gal
Engine 2.7 US gal
Final drive, each side 0.29 US gal
Swing drive 0.52 US gal
Hydraulic tank  14.8 US gal
Operating weight (approximate)

Operating weight includes 3 710 mm one-piece boom, 2 250 mm arm, ISO 7451 heaped 0.20 m3 bucket, blade, rated capacity of lubricants, coolant, full fuel tank, operator, and standard equipment.

Track Shoes Operating Weight Ground Pressure
Road liner 450 mm 8 070 kg 35.8 kPa / 0.36 kg/cm2
Triple grouser 450 mm 7 930 kg 35.8 kPa / 0.36 kg/cm2
Triple grouser 600 mm 8 250 kg 26.8 kPa / 0.27 kg/cm2
Rubber shoe 450 mm 7 910 kg 35.0 kPa / 0.35 kg/cm2

Operating weight includes 12 ft. 2 in one-piece boom, 7 ft. 5 in arm, ISO 7451 heaped 0.26 yd3 bucket, blade, rated capacity of lubricants, coolant, full fuel tank, operator, and standard equipment.

Track Shoes Operating Weight Ground Pressure
Road liner 18" 17,791 lbs. 5.20 psi
Triple grouser 18" 17,483 lbs. 5.20 psi
Triple grouser 24" 18,188 lbs. 3.90 psi
Rubber shoe 18" 17,438 lbs. 5.10 psi

Engine:

  • Komatsu SAA3D95E-1
  • Auto deceleration
  • Air cleaner, double element with auto dust evacuator
  • B20 Biodiesel compatible*
  • Cooling system viscous fan clutch, suction type
  • Cooling system with expansion tank
  • Engine oil-pan drain valve
  • Fixed turbocharger
  • Komatsu Diesel Oxidation Catalyst (KDOC)

Electrical system:

  • Alternator, 24 V/60 A
  • Batteries, 2 x 12 V/55 Ah
  • Battery disconnect switch
  • Lock out/tag out provisioned
  • Starting motor 24 V/4.5 kW

Guards and covers:

  • Fan guard
  • Pump/engine partition cover
  • Diesel ground level fuel fill and hydraulic tank fill cap are under lockable side covers
  • Car body swivel guards

Operator environment:

  • 12 V x 2 power supply
  • Attachment flow switching through monitor
  • Auto climate control
  • Auto idle shutdown
  • Cab includes: antenna, multifunction audio with USB and Bluetooth wireless technology, floormat,intermittent front windshield wiper and washer, large ceiling hatch, pull-up front window, removable lower windshield
  • Handrails
  • Komtrax 5.0 (cellular 4G system)
  • LED working light on boom
  • LED working light on cab
  • Lock lever auto lock function
  • Monitor panel
  • Operator identification function
  • Rearview mirrors (LH, rear)
  • Rearview monitoring system
  • ROPS cab (ISO 12117-2)
  • Seat belt, 78 mm
  • Suspension seat
  • Swing holding brake
  • Travel alarm
  • Travel Hi/Lo switch on blade control lever

Hydraulic system:

  • Dual stage relief valve
  • Proportional control on floor for auxiliary hydraulics
  • Hydraulic control unit-1 additional actuator
  • One-way/two-way auxiliary hydraulic flow
  • Operation pattern change-over valve (two-way, ISO/BH)
  • One-variable piston pump and one gear pump
  • Auxiliary circuit return filter and accumulator
  • Automatic swing brake
  • Automatic load sensing two speed travel

Work equipment:

  • Blade 2330 mm (welded cutting edge type)
  • Counterweight, 805 kg

Undercarriage:

  • Triple grouser shoe, 450 mm

*Up to 20% blended biodiesel fuel and paraffine fuel can be used. Please consult your Komatsu distributor for detail.

Engine:

  • Komatsu SAA3D95E-1
  • Auto deceleration
  • Air cleaner, double element with auto dust evacuator
  • B20 Biodiesel compatible*
  • Cooling system viscous fan clutch, suction type
  • Cooling system with expansion tank
  • Engine oil-pan drain valve
  • Fixed turbocharger
  • Komatsu Diesel Oxidation Catalyst (KDOC)

Electrical system:

  • Alternator, 24 V/60 A
  • Batteries, 2 x 12 V/55 Ah
  • Battery disconnect switch
  • Lock out/tag out provisioned
  • Starting motor 24 V/4.5 kW

Guards and covers:

  • Fan guard
  • Pump/engine partition cover
  • Diesel ground level fuel fill and hydraulic tank fill cap are under lockable side covers
  • Car body swivel guards

Operator environment:

  • 12 V x 2 power supply
  • Attachment flow switching through monitor
  • Auto climate control
  • Auto idle shutdown
  • Cab includes: antenna, multifunction audio with USB and Bluetooth wireless technology, floormat,intermittent front windshield wiper and washer, large ceiling hatch, pull-up front window, removable lower windshield
  • Handrails
  • Komtrax 5.0 (cellular 4G system)
  • LED working light on boom
  • LED working light on cab
  • Lock lever auto lock function
  • Monitor panel
  • Operator identification function
  • Rearview mirrors (LH, rear)
  • Rearview monitoring system
  • ROPS cab (ISO 12117-2)
  • Seat belt, 3.1"
  • Suspension seat
  • Swing holding brake
  • Travel alarm
  • Travel Hi/Lo switch on blade control lever

Hydraulic system:

  • Dual stage relief valve
  • Proportional control on floor for auxiliary hydraulics
  • Hydraulic control unit-1 additional actuator
  • One-way/two-way auxiliary hydraulic flow
  • Operation pattern change-over valve (two-way, ISO/BH)
  • One-variable piston pump and one gear pump
  • Auxiliary circuit return filter and accumulator
  • Automatic swing brake
  • Automatic load sensing two speed travel

Work equipment:

  • Blade 7'7" (welded cutting edge type)
  • Counterweight, 1,775 lbs.

Undercarriage:

  • Triple grouser shoe, 18"

*Up to 20% blended biodiesel fuel and paraffine fuel can be used. Please consult your Komatsu distributor for detail.

Guards and covers:

  • Bolt-on top guard (operator protective guards level 2)
  • Cab front guard
    — Full height front window mesh guard (Level 1)

Work equipment:

  • Boom,
    — 3405 mm swing type
  • Arm,
    — 2100 mm arm assembly with provision for hydraulic thumb
  • Blade,
    — 2470 mm wide blade (requires 600 mm shoes)

Undercarriage:

  • Shoes:
    — 450 mm Road Liner shoes
    — 600 mm Triple grouser shoes
  • Rubber belt track
    — 450 mm

Guards and covers:

  • Bolt-on top guard (operator protective guards level 2)
  • Cab front guard
    — Full height front window mesh guard (Level 1)

Work equipment:

  • Boom,
    — 11'2" swing type
  • Arm,
    — 6'11" arm assembly with provision for hydraulic thumb
  • Blade,
    — 8' 1" wide blade (requires 24" shoes)

Undercarriage:

  • Shoes:
    — 18" Road Liner shoes
    — 24" Triple grouser shoes
  • Rubber belt track
    — 18"
Support you can count on

Find what works for you