• 117,892 lbs Max Gross Vehicle Weight
  • 332 @2000 rpm Gross HP
  • 30.9 U.S. tons Capacity


The 30.9 ton capacity HM300-5 is powered by a Tier 4 final Komatsu engine. A Komatsu Traction Control System along with two working modes and a standard payload meter (PLM) provide the operator with the tools needed to complete the job efficiently and profitably even in the most severe underfoot conditions. A heated, center located air suspension operator seat, a forward facing training seat, separate rear view monitor, and large LED multi-language monitor ensure the operator is working productively in comfort throughout a full shift.

HM300-5 Walkaround  >


Tier 4 Final Engine

The Komatsu SAA6D125E-7 engine is EPA Tier 4 Final emissions certified and provides exceptional performance while reducing fuel consumption. Based on Komatsu proprietary technologies developed over many years, this new diesel engine reduces nitrogen oxides (NOx) by more than 80% when compared to Tier 4 interim levels. Through the in-house development and production of engines, electronics, and hydraulic components, Komatsu has achieved great advancements in technology, providing high levels of performance and efficiency in virtually all applications.

Komatsu Auto Idle Shutdown

Komatsu auto idle shutdown automatically shuts the engine down after idling for a set period of time to reduce unnecessary fuel consumption and exhaust emissions. The amount of time before the engine is shutdown can be easily programmed from 5 to 60 minutes.

Selectable Working Modes

Power mode
Appropriate for higher production jobs and uphill hauling applications. The power mode increases the engine maximum output and raises the upshift and downshift engine speeds during operation.

Economy mode
Appropriate for lighter work on flat ground. The economy mode lowers the engine maximum output along with lowering the upshift and downshift engine speeds during operation.

Large Capacity Body

The HM300-5 has a heaped body capacity of 17.1 m3 22.4 yd3. The low loading height of 2830 mm 9'3" enables easy loading. The body is built of high strength, wear-resistant steel with a Brinell hardness of 400 and the body shape provides excellent load stability. HM300’s frame employs a rigid box structure utilizing high tensile strength steel, and is rugged enough for the toughest jobs.

Komatsu Designed Electronically Controlled Countershaft Transmission

The Komatsu designed electronically controlled transmission called K-ATOMiCS has been a success in Komatsu’s dump trucks. The electronic clutch modulation system ensures proper clutch pressure when the clutch is engaged. The total control system controls both the engine and the transmission by monitoring the vehicle conditions. This high technology system assures smooth shifts with minimal shock and maximizes the power train life.

Komatsu Traction Control System (KTCS)

The KTCS was developed by Komatsu to allow for maximum machine performance in soft and slippery ground conditions. Komatsu leveraged its prior experience with the traction control systems in bulldozers and rigid dump trucks to develop this system for use in articulated dump trucks.
The KTCS monitors the wheel speeds on the front and middle axles. If the system detects wheel slip, it will automatically engage the inter axle lock to improve machine performance. If the machine continues to detect wheel slip it will brake the wheel that slip was detected on. It will continually monitor the wheel speeds and engage the brakes as necessary.
KTCS is automatically activated and deactivated. The inter-axle lock can also be engaged by the operator via a rocker switch located on the dash panel.

Payload Meter (PLM)

A payload meter is included as standard equipment on the new HM300-5. The payload tonnage is displayed on the Machine Monitor and is visible to the haul truck operator. An external display lamp mounted on the top of the cab communicates payload status to the loader operator. The external display lamp indicator lights are visible from both sides of the truck so it is always in sight of the loader operator.

PLM data is transmitted by KOMTRAX and can be accessed via the internet. Detailed data is stored in the truck’s controller and can be directly downloaded from the truck to a PC.

Rear View Monitoring System

The rear view camera and monitor are equipped as standard.

Hydraulically Controlled Wet Multiple-disc Brakes and Retarder

Wet multiple-disc brakes with proven performance in other Komatsu dump trucks are tailored for use in the HM300-5. The large-capacity, continuously cooled, wet-multiple disc brakes also function as a highly responsive retarder which gives the operator greater confidence at higher speeds when travelling downhill.

Retarder Absorbing Capacity (continuous descent): 392 kW 526 HP

ECO Guidance

The monitor panel provides guidance to the operator to help promote energy saving operation. For example, if the operator stops the machine for a long period of time with the engine idling, the message “Avoid excessive engine idling” is displayed on the monitor panel. The ECO guidance function displays six (6) messages:
• Avoid Excessive Engine Idling
• Release the Hoist Lever
• Operating the Accelerator Pedal with Brake Actuated Lowers Fuel Economy
• Shift Up
• Avoid Operating the Accelerator Pedal with the Body Moving Down
• Avoid Hard Use of Steering

ECO Gauge

The ECO gauge indicates a momentary fuel consumption rate during operation.

Operating the machine by keeping the gauge within the green zone leads to energy-saving operation.

Ground Access to Filters

The oil filters of the transmission and the brake systems can be serviced from ground level.

Easy Access DEF Tank

Located to the rear of the fuel tank, and easy to access.

Tiltable Cab with Power Tilt

The cab can be tilted rearward by 29 degrees to provide easy access to the engine and transmission for service. Electrically-operated cab tilt is standard.



Model Komatsu SAA6D125E-7*
Type Water-cooled, 4-cycle
Aspiration Turbo-charged, after-cooled, cooled EGR
Number of cylinders 6
Bore 125 mm 4.92"
Stroke 150 mm 5.91"
Piston displacement 11.0 ltr 671 in3
Horsepower :
SAE J1995 248 kW 332 HP
ISO 9249 / SAE J1349 242 kW 324 HP
Rated rpm 2000 rpm
Fan drive type Hydraulic driven
Maximum torque 171 kg•m 1,237 ft lbs
Fuel system Direct injection
Governor Electronically controlled
Lubrication system:
Method Gear pump, force-lubrication
Filter Full-flow type
Air cleaner   Dry type with double elements and precleaner, plus dust indicator
*EPA Tier 4 Final emissions certified


Torque converter
3-elements, 1-stage, 2-phase
Full-automatic, counter-shaft type
Speed range
6 speeds forward and 2 reverse
Lockup clutch
Wet, single-disc clutch
Torque converter drive in 1st gear, direct drive in 1st lockup and all higher gears
Torque converter drive and direct drive in all gear
Shift control
Electronic shift control with automatic clutch modulation in all gear
Maximum travel speed 58.6 km/h 36.4 mph


Full time all wheel drive with Komatsu Traction Control System (K-TCS)

Final drive type Planetary gear
Differential 3.154
Planetary 4.667

Suspension System

Front Hydro-pneumatic suspension
Rear Combined hydro-pneumatic and rubber suspension system

Steering System

Articulated type, fully hydraulic power steering with two double-acting cylinders
Supplementary steering
Automatically actuated, electrically powered
Standard   ISO5010, SAE J1511
Minimum turning radius, wall to wall 8.10 m 26'7"
Articulation angle
45° each direction


Standard ISO3449 (FOPS)
ISO3471 (ROPS)


Service brakes Full-hydraulic control, oil-cooled multiple-disc type on front and center axles
Standard ISO3450
Parking brake Spring applied, caliper disc type
Retarder Front and center axle brakes act as retarder

Main Frame

Type Articulated type, box-sectioned construction on front and rear Connected by strong torque tubes.


Struck16.9 13.4 m3 17.5 yd3
Heaped (2:1, SAE) 17.1 m3 22.4 yd3
Payload 28.0 metric tons 30.9 U.S. tons
Material - high tensile strength steel 130 kg/mm2 184,925 psi
Material thickness:
Bottom 14 mm 0.55"
Front 8 mm 0.31"
Sides 12 mm 0.47"
Target area - (inside length x width) 5250 mm x 2685 mm 17'3" x 8'10"
Heating Exhaust heating (optional)

Hydraulic System

Hoist cylinder Twin, telescopic type
Relief pressure 300 kg/cm2 / 29.4 Mpa 4264 psi
Hoist time 10.5 sec

Weight (approximate)

Empty weight 25,395 kg 55,986 lbs
Gross vehicle weight 53,475 kg
117,892 lbs
Weight distribution:
Front axle 58.9%
Center axle 22.5%
Rear axles 18.6%
Front axle 30.8%
Center axle 36.0%
Rear axles 33.2%


Standard tire 23.5 R25

Service Refill Capacities

Fuel tank 388 ltr 102.5 U.S. gal
DEF tank
32.8 ltr 8.7 U.S. gal
Engine oil 35 ltr
9.2 U.S. gal
Torque converter, transmission and retarder cooling 80 ltr
21.1 U.S. gal
Differentials (total) 71.5 ltr
18.9 U.S. gal
Final drives (total) 23 ltr 6.1 U.S. gal
Hydraulic system 103 ltr 27.2 U.S. gal
Suspension (total) 10.4 ltr 2.7 U.S. gal


  • Air cleaner, dry type, double elements
  • Air cleaner dust level indicator
  • Air pre-cleaner
  • Alternator, 90 A, 24 V
  • Alarm, backup
  • Anti-slip material on fenders
  • Auxiliary steering system, automatic, electric
  • Back-up lamp
  • Batteries, 2 x 12 V/200 Ah
  • Battery disconnect
  • Centralized greasing
  • Color rear view camera and monitor
  • Coolant temperature alarm and lamp
  • Dump counter
  • ECO Guidance
  • Electronic hoist control system
  • Electric circuit breaker, 24 V
  • Electric priming fuel pump
  • Electronic pump for hydraulic tilt cab
  • Engine, Komatsu SAA6D125E-7
  • Engine underguard
  • Engine shutdown secondary switch
  • Front view mirror
  • Full-automatic F6-R2 transmission with lock-up torque converter & K-ATOMiC shift control
  • Hazard lamps
  • Hand rails for platform and ladder
  • Headlights, front (high and low)
  • Heated rearview mirrors, LH and RH side
  • Horn, electric
  • Hydraulic driven cooling fan, for after cooler
  • Hydraulic driven cooling fan, for radiator
  • Hydropneumatic suspension, front and rear
  • Interaxle lockup, wet disc clutch type, controlled by KTCS
  • Komatsu Traction Control System (KTCS)
  • Komatsu Diesel Particulate Filter (KDPF)
  • Komatsu Variable Geometry Turbocharger (KVGT)
  • Ladders LH side
  • Mud guards
  • Parking brake
  • Payload Meter (PLM)
  • Protective grille for rear window
  • Propeller shaft guards, front and rear
  • Provision for tailgate
  • Retarder/brake system
  • Rims for 23.5 x 25, set of 6
  • ROPS/FOPS cab Level 2
    --2 x DC12V electrical outlets

    --12V cigarette lighter

    --Air conditioner/Heater/Defroster


    --Color LCD/TFT multi-monitor

    --Cup holder

    --Floor mat

    --Operator seat, reclining, air suspension type with 3-point retractable seat belt, 76 mm
    3" width lap belt, 50 mm 2" width shoulder belt

    --Passenger seat with 2-point retractable seat belt, 76 mm
    3" width

    --Power window (LH)

    --Space for lunch box

    --Sliding window (RH)

    --Steering wheel, tilt and telescopic

    --Sun visor, front window

    --Tiltable ROPS cab with FOPS, sound suppression type

    --Windshield washer and wiper, front and rear
  • Selective Catalytic Reduction (SCR) system
  • Starting motor, 7.5 kW
  • Steering joint locking assembly
  • Step (right side)
  • Stop, tail, and turn signal lamps (LED)
  • Tool box
  • Transmission underguard
  • Two mode engine power system (Economy and Power)
  • Work lamps, LH and RH side


  • 23.5 x 25 tires
  • 750/65 R25 rims
  • 750/65 R25 tires
  • Body, 17.1 m3 22.4 yd3
  • Body, exhaust heated, 17.1 m3 22.4 yd3
  • Tail gate, scissors type