HD785-7 SPECIFICATION

Compatible Unit Serial Number : 7001 and up 

Introduction:

​The Komatsu HD785-7 continues the tradition for this iconic truck. Known globally as the leading 100 tonne class truck due to its outstanding productivity and reliability, the HD785-7 through latest technology adoption continues to outperform all competitors.

The HD785-7 meets our customer’s demands through superior;

• Payload
• Engine Horsepower
• Component quality and technology

 Quality and Reliability to deliver customer outcomes.

SPECIFICATION AND TECHNICAL DATA

Specification Drawing

Machine Model : HD785-7

Serial No. : 7001 and up

Power Train

1. Torque Converter

• Structure : 3-element, 1-stage, 2-phase
• Lock- up clutch : Hydraulically actuated, wet-type, multiple-disc clutch

2. Transmission

• Type : TORQFLOW planetary gear. Fully automatic, electrically-hydraulically actuated, force-feed type pump.
• No. of speeds : F7, R2

3. Reduction Gear

• Type : Spiral bevel gear, splash lubrication
• Reduction ratio : 3.357
• Differential type : Straight bevel gear, splash lubrication

4. Final Drive

• Type : Planetary gear, splash lubrication
• Reduction ratio : 6.333

Steering System

• Type : Fully hydraulic steering system

Suspension

1. Axle type

• Front axle : Independent suspension (Mac Pherson type)
• Rear axle : Full floating

2. Suspension method

• Front axle : Hydropneumatic (Automatic damping force selection type)
• Rear axle : Hydropneumatic

Tires

1. Size and No.

• Front tire : 27.00R49**E4
• Rear tire : 27.00R49**E4

2. Tire pressure

• Front and rear tire : 686 {7} kPa {kg/cm2}

Brake System

1. Service brake

• Front Brake : Oil cooled multiple disc brake, Hydraulically controlled
• Rear Brake : Oil cooled multiple disc brake, Hydraulically controlled

2. Parking brake

• Multiple disc wet type disc brake, Hydraulically released spring type

3. Retarder

• Oil cooled multiple disc type, Hydraulically controlled

Hydraulic System

1. Hydraulic pump

     - For both steering and work equipment

• Type : Gear pump
• Delivery (at engine rated speed 1,900 rpm) : 580 l/min

     - For charging torque converter

• Type : Gear pump
• Delivery (at engine rated speed 1,900 rpm) : 380 l/min

     - For brake cooling

• Type : Gear pump
• Delivery (at engine rated speed 1,900 rpm) : 580 l/min

2. Cylinder

     - Hoist cylinder

• Type : 2-stage piston type (only 2nd stage: double-acting)
• No. 1st bore x stroke - 2nd bore x stroke : 2 - 215 mm x 1,045 mm - 180 mm x 1,040 mm

     - Steering cylinder

• Type : Piston type, double acting
• No. - bore x stroke : 2 - 110 mm x 475 mm

Weight Table

Note: This weight table is a guide for use when transporting or handling component.

Machine model	HD785-7
Serial Number	7001 and up
Engine assembly Output shaft assembly Radiator assembly Fuel tank Torque converter Transmission assembly Drive shaft assembly (front) Drive shaft assembly (rear) Rear axle assembly . Differential . Final drive (one-side) . Rear brake (one-side) Front axle (one-side) (with A frame, knuckle arm) Front brake (one-side) Front suspension cylinder (one-side) Rear suspension cylinder (one-side) Frame assembly (with rear support, mount bracket ) Cab assembly Operator’s seat Steering cylinder (one-side) Hoist cylinder (one-side) Demand valve Steering valve Hoist valve Hydraulic pump (SAR180+180+1) Hydraulic pump (SDR100+100+SAR25) Hydraulic pump (SAR180+180) Dump body	3,365 171 920 495 626 1,812 42 211 10,930 1,127 2,870 1,170 2,530 742 706 246 9,194 1,585 45 87 336 66 24 63 49 46 45 15,200

Fuel, Coolant and Lubricants

• ASTM: America Society of Testing and Material

	Engine oil pan	Transmission case	Steering, hoist oil tank	Front suspension	Rear suspension
Specified capacity (liters)	134	368	270	29.8 each for right and left	16.5 each for right and left
Refill capacity (liters)	129	205	175	-	-

	Brake sub tank	Differential case	Final drive case	Fuel tank	Cooling system
Specified capacity (liters)	36	137	64 each for right and left	1,308	283
Refill capacity (liters)	36	137	64 each for right and left	-	279

Notice

Use only diesel fuel.

The engine mounted on this machine employs electronic control and a high-pressure fuel injection device to obtain good fuel consumption and good exhaust gas characteristics. For this reason, it requires high precision for the parts and good lubrication. If kerosene or other fuel with low lubricat-ing ability is used, there will be a big drop in durability.

Note 1: SAE0W30EOS and SAE5W40EOS must be fully synthetic and HTHS (High-Temperature High-Shear Viscosity @ 150 °C), specified by ASTM D4741 must be equal to or higher than 3.5mPa-S(3.5cP).

Komatsu EOS0W30 and EOS5W40 are the most suitable oils.

Note 2: Power train oil has different properties from engine oil. Be sure to use the recommended oils.

Note 3: Hyper grease (G2-T, G2-TE) has a high performance.

When it is necessary to improve the lubricating ability of the grease in order to prevent squeaking of pins and bushings, the use of G2-T or G2-TE is recommended.

Note 4: Supercoolant (AF-NAC)

a. The coolant has the important function of preventing corrosion as well as preventing freezing. Even in the areas where freezing is not an issue, the use of antifreeze coolant is essential. Komatsu machines are supplied with Komatsu Super coolant (AF-NAC). Komatsu Super coolant (AFNAC) has excellent anticorrosion, antifreeze and cooling properties and can be used continuously for 2 years or 4,000 hours.

Komatsu Super coolant (AF-NAC) is strongly recommended wherever available.

b. For details of the ratio when diluting super coolant with water, see "Mixing rate of water and super coolant".

When the machine is shipped from the factory, it may be filled with coolant containing 30% or more

Super coolant (AF-NAC). In this case, no adjustment is needed for temperatures down to -10°C (14°F). (never dilute with water)

When temperature is below -10°C (14°F), adjust the ratio of Super coolant and water, see "Mixing rate of water and super coolant".

c. To maintain the anticorrosion properties of Super coolant (AF-NAC), always keep the density of Super coolant between 30% and 68%.

Mixing rate of water and super coolant

Min. atmospheric temperature	°C	-10	-15	-20	-25	-30
	°F	14	5	-4	-13	-22
Amount of antifreeze	Liters	83.7	97.65	111.6	125.55	139.5
	US Gal	22.113	25.799	28.484	33.170	36.855
Amount of water	Liters	195.3	181.35	167.4	153.45	139.5
	US Gal	51.597	47.911	44.226	40.540	36.855
Volume ratio	%	30	35	40	45	50