• 365,967 lbs Max Gross Vehicle Weight
  • 1,200 @1900 rpm Gross HP
  • 101.6 U.S. tons Capacity


The HD785-8 is a Tier 4 Final compliant rigid frame haul truck with a rated payload of 101.6 US tons designed for high production mining, quarry, and aggregate applications. Oil cooled, multiple-disc brakes on all four wheels provide excellent retarding capability for downhill travel while the Komatsu SAA12V140E-7 engine outputs 1,140 net horsepower for high productivity on grade. The McPherson strut type front suspension allows the HD785-8 to have a tight turning radius of 33’2” for excellent maneuverability when spotting or positioning to dump. Komatsu Traction Control (KTCS) is standard on the HD785-8 and provides optimum traction in various ground conditions. The new cab with upgraded trainer seat keeps operators comfortable throughout long shifts, and access is made simple with the standard diagonal angled stairway. Standard KomVision all around monitoring system provides the operator with a 360-degree bird’s-eye view utilizing a 6-camera system on a dedicated display.


Productivity Features

  • Automatic Retard Speed Control (ARSC) allows the operator to set and maintain a constant downhill travel speed
  • High performance Komatsu SAA12V140E-7 engine (net 1,140 HP/849 kW) provides high productivity on grade
  • Komatsu Traction Control System (KTCS) monitors for wheel spin and automatically applies brakes independently for optimum traction in various ground conditions
  • No use of Selective Catalytic Reduction (SCR) or Diesel Exhaust Fluid (DEF)
  • Oil cooled, multiple-disc brakes on all four wheels provide high retarding capability (1,770 HP/1320 kW)
  • Seven-speed, fully automatic K-ATOMiCS transmission with 2 selectable reverse speeds and skip shift function
  • Tight turning radius: 10.1 m 33' 2"
  • Variable Geometry Turbocharger (VGT) is hydraulically actuated to provide optimum air flow under various speed and load conditions

Operator Environment

  • Air suspension, heated & ventilated operator seat with three-point seat belt and standard trainer seat with lap belt
  • Automatic climate control system
  • Diagonal access stairway with handrails for easy access
  • Front and rear hydropneumatic suspension provides a smooth ride
  • Heated rearview mirrors
  • KomVision provides bird’s-eye view utilizing 6-camera system on dedicated display
  • LED head lamps (high and low beam), side lamps, and rear combination lamps
  • Machine monitor with high resolution 7-inch color LCD display
  • Rearview monitoring system on dedicated display
  • Viscous cab mounts for a quiet, comfortable ride

Ecology and Economy

  • Auto Idle Setting System (AISS) for quick machine warm up
  • Auto Idle Shutdown helps reduce idle time and operating costs
  • Energy savings operation ecology guidance
  • Hydraulically operated, reversible fan
  • Komatsu SAA12V140E-7 engine is EPA Tier 4 Final emissions certified
  • Mode selection system with variable horsepower control

Reliability Features

  • 10-10-20 payload policy
  • Engine pre-lubrication system
  • High rigidity frame
  • Integrated Payload Meter (PLM)
  • Robust dump body design

Maintenance Features

  • Advanced monitoring system with onboard diagnostics, no laptop required
  • Anchored tie off points (ISO 14567) around the machine provide technicians locations to attach service lanyards
  • Centralized ground level access arrangement of filters and greasing points
  • Fast fuel fill coupler
  • Ground level battery isolator, starter isolator and machine immobilization switch with lockout / tagout capabilities
  • Ground level service center for fluid fill and evacuation
  • Jump start receptacle
  • KOMTRAX Plus allows remote access to maintenance and performance information
  • Modular radiator core system



Komatsu SAA12V140E-7*
Water-cooled, four-cycle
Turbo-charged, after-cooled, cooled EGR
Number of cylinders
Bore x Stroke 140 mm x 165 mm 5.51" x 6.50"
Piston displacement 30.48 ltr 1,860 in³

    SAE J1995 - Gross 895 kW 1,200 HP
    ISO 9249 / SAE J1349 - Net 879 kW
1,178 HP
    Rated rpm
1900 rpm
Fan drive type
Maximum torque 517 kg•m 3,739 ft lbs
Fuel system
Direct injection
Electronically controlled
Lubrication system

Gear pump, force-lubrication
Full-flow type
Air cleaner
Dry type with double elements, precleaner and evacuator valve

*EPA Tier 4 Final emissions certified


Torque converter
Three-elements, one-stage, two-phase
Full-automatic, planetary type
Speed range
Seven speeds forward and two reverse
Lockup clutch.
Wet, multiple-disc clutch
Torque converter drive in 1st gear, direct drive in 1st lockup and all higher gears
Torque converter drive and direct (lockup)
Shift control
Electronic shift control with automatic clutch modulation in all gears
Maximum travel speed 65 km/h 40.4 mph


Rear axles   Full-floating
Final drive type   Planetary gear
    Differential   2.944
Planetary   7.235

Suspension System

McPherson strut type front suspension and four-link type rear axle suspension with independent, hydropneumatic cylinders.

Effective cylinder stroke:

    Front suspension 320 mm 1' 0.6"
    Rear suspension 127 mm 5"
Rear axle oscillation:
    Oil stopper
    Mechanical stopper


Steering System

Fully hydraulic power steering with two double-acting cylinders
Secondary steering
Automatic/Manual control
(Meets ISO 5010 and SAE J1511)
Minimum turning radius 10.1 m 33'2"
Maximum steering angle



FOPS (ISO 3449 level II), ROPS (ISO 3471)


Brakes meet ISO 3450 standards.

Service brakes:

Fully hydraulic control, oil-cooled multiple-disc type
Fully hydraulic control, oil-cooled multiple-disc type
    Parking brake
Spring applied, multiple-disc type
Oil-cooled, multiple-disc front and rear brakes act as retarder
    Secondary brake
Manual pedal operation when hydraulic pressure drops below the rated level, parking brake is automatically actuated
Brake surface

    Front 39195 cm² 6,075 in²
    Rear 71858 cm² 11,138 in²

Main Frame

Box-sectioned structure



    Struck 40 m³ 52.3 yd³
    Heaped (2:1, SAE) 60 m³ 78.5 yd³
Payload 92.2 metric tons 101.6 U.S. tons
400 brinell hardness high tensile strength steel
V-shape body with V-bottom
Material thickness:

    Bottom 19 mm 0.75"
    Front 12 mm 0.47"
    Sides 9 mm 0.35"
Target area (inside length x width) 7070 mm x 5150 mm 23'2"x 16'11"
Height at full dump 10080 mm 33'1"
Exhaust heating

Hydraulic System

Hoist cylinder
Twin, two-stage telescopic type
Relief pressure 20.6 MPa / 210 kg/cm² 2,990 psi
Hoist time
11.5 sec

Weight (approximate)

Rated empty vehicle weight 73800 kg 162,701 lb
Rated gross vehicle weight 166000 kg 365,967 lb
Weight distribution (Empty):

    Front axle
    Rear axle
Weight distribution (Loaded):

    Front axle
    Rear axle


Standard tire   27.00 R49

Service Refill Capacities

Fuel tank 1322 ltr 349.2 U.S. Gal
Engine oil 138 ltr 36.5 U.S. Gal
Torque converter, transmission and retarder cooling 530 ltr 140.0 U.S. gal
Differentials 203 ltr 59.6 U.S. Gal
Final drives (total) 116 ltr 30.6 U.S. Gal
Hydraulic system 385 ltr 101.7 U.S. Gal
Suspension (total) 92.6 ltr 24.5 U.S. Gal



  • Air cleaner, double element with restriction indicator (qty 2)
  • Auto Idle Shutdown
  • Automatic Idling Setting System (AISS)
  • Electric priming fuel pump
  • Engine, KOMATSU SAA12V140E-7, 12 cylinder, turbocharged, after cooled, EGR cooled, diesel
    Gross HP: 1200 HP (895 kW) / 1900 RPM (SAE J1995)
    Net HP: 1140 HP (849 kW) / 1900 RPM (ISO 9249 / SAE J1349)
  • Engine pre-lubrication system
  • Engine secondary shutdown switch
  • Fan, hydraulically driven, reversible
  • Komatsu diesel particulate filter (KDPF) (qty 2)
  • Radiator, lead free, modular core


  • Alternator, 140 amp, 24 volt
  • Back-up alarm
  • Batteries, 4 x 12V
  • Battery isolator
  • Electric circuit breakers, 24V
  • Emergency stop switch, ground level
  • Horn, electric
  • Lights
  • Access ladder lamps
  • Back-up Lamps, rear
  • Engine compartment lamp
  • Fog lamps
  • Head lamps, high and low beam, LED
  • Side working lamps, LH & RH, LED
  • Stop and tail Lamps, LED
  • Turn signals, hazard warning, front & rear, LED
  • Starter isolator
  • Starting motors, 2 x 11.0 kW, electric


  • 7-speed transmission, fully automatic, (7F, 2R)
  • Brake cooling oil recovery tank
  • Brakes, oil cooled, multiple disc, hydraulically controlled, front & rear
  • Komatsu Traction Control System (KTCS)
  • Neutral coast inhibitor
  • Parking brake, integrated in front & rear brakes
  • Retarder, automatic & manual
  • Secondary brake, pedal actuated, variable
  • Skip shift function
  • Speed limiter
  • Torque converter with electronic lockup control


  • Cab with built-in ROPS/FOPS (ISO 3471/ISO 3449)
  • 12V outlet (qty 2)
  • Automatic climate control system with cab pressurization
  • Body hoist control, electric
  • Cigarette lighter and ashtray
  • Cup holder
  • Door, LH & RH
  • KomVision camera system with dedicated monitor
  • Machine monitor with 7" color LCD display
  • Mode selection system with Variable Horsepower Control (VHPC)
  • Operator seat, air suspension, heated, ventilated with 3-point 3" retractable seat belt
  • Power windows, LH & RH
  • Radio, AM/FM with aux input, USB, & bluetooth
  • Rearview mirror, outside cab mount, heated (qty 2)
  • Rearview monitoring system with dedicated monitor
  • Secondary steering, automatic & manual
  • Steering wheel, tilt and telescopic
  • Sunvisor (qty 2)
  • Tinted glass with electric defogger
  • Trainer seat with 3" retractable lap belt
  • Underview mirror
  • Wiper/washer, windshield (intermittent)
  • Diagonal access stairway


  • Cab & platform guard
  • Catwalk with handrails, skid resistant
  • Driveline guards, front & rear
  • Engine side covers
  • Engine underguard
  • Exhaust thermal guard
  • Fire safety shield (located behind engine)
  • Mud flaps
  • Rock ejector bars
  • Transmission underguard


  • Anchor points, tie off type (ISO 14567)
  • Automatic Retard Speed Control (ARSC)
  • Dump counter
  • Ecology guidance and ecology gauge
  • Fast fill coupler for fuel tank
  • Filler cap lock & cover lock
  • Ground level service center
    -Centralized KOWA sampling
    -Fluids ports
    Transmission, engine, brake control, steering and hoist oil
  • Hydropneumatic Suspension, Front & Rear
  • Jump start receptacle
  • KOMTRAX Plus®
  • Machine immobilization switch
  • Overload prevention system
  • Overrun warning and prevention
  • Overturn warning system
  • Payload meter
  • PM service connectors
  • Rims for 27.00 R49 tires with large bore valve stems (qty 6)
  • Safety pins (qty 2)
  • Wheel chocks (qty 2)



  • Dump body, 78.5 yd3
  • Steel liners for rock body (78.5 yd3)
  • Body heating kit


  • Michelin XDR2B (qty 6)
  • Bridgestone VMTP (qty 6)


  • Cold weather package (electric heaters for engine oil & coolant heater)