Komatsuengine(no series)

Komatsu 3D72-2GA(S/N 07992-UP)

Maintenance schedule, common problems & OEM parts breakdown

The Komatsu 3D72-2GA is a diesel engine powering the PC05-5, PC05-6, PC05-7, and PC07-1 crawler excavator series. These compact machines operate in the 5 to 7-ton class with operating weights ranging from approximately 5,000 to 7,500 kg (11,000 to 16,500 lb). Production spans the early 2000s through the mid-2010s, bridging the gap between the older PC05-3/PC07-1 predecessors and the later PC07-2/PC10-5 successors. Configurations offered include standard and long-reach booms, varying undercarriage widths, and regional emissions packages.

Across generations, the 3D72-2GA engine replaced earlier naturally aspirated or early turbo variants, introducing improved fuel efficiency and emissions compliance for its era. The machine remains significant in the used and parts market due to its widespread use in municipal and utility work. Its compact size allows access to confined spaces, while the 3D72 series engine is known for durability and ease of overhaul, keeping aftermarket support and core availability high.

Below: full specifications, fluids & capacities, the factory service schedule, common service parts, verified fault codes, what owners discuss, attachment guidance, the complete assembly directory, and a serial-number reference. Complete parts lists with full OEM part numbers, exploded diagrams, quantities, and fitment data are available free in Heavy Parts AI.

Komatsu 3D72-2GA(S/N 07992-UP) specifications

Engine

Model3D72-2GA
Series72 Series
Cylinders3
DisplacementNot documented for this exact serial range — verify with your dealer
Gross/Net PowerNot documented for this exact serial range — verify with your dealer
Emissions TierNot documented for this exact serial range — verify with your dealer

Weights

Operating WeightNot documented for this exact serial range — verify with your dealer
Shipping WeightNot documented for this exact serial range — verify with your dealer
Ground PressureNot documented for this exact serial range — verify with your dealer

Dimensions

Transport LengthNot documented for this exact serial range — verify with your dealer
Transport WidthNot documented for this exact serial range — verify with your dealer
Transport HeightNot documented for this exact serial range — verify with your dealer
Track GaugeNot documented for this exact serial range — verify with your dealer
Ground ClearanceNot documented for this exact serial range — verify with your dealer

Performance

Travel SpeedNot documented for this exact serial range — verify with your dealer
GradeabilityNot documented for this exact serial range — verify with your dealer

Service capacities (summary)

Fuel TankNot documented for this exact serial range — verify with your dealer
Hydraulic SystemNot documented for this exact serial range — verify with your dealer
Engine OilNot documented for this exact serial range — verify with your dealer
Cooling SystemNot documented for this exact serial range — verify with your dealer

Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.

Komatsu 3D72-2GA(S/N 07992-UP) maintenance schedule

Service intervalTasks
Every 10 h
  • Check engine oil level and condition.
  • Check hydraulic fluid level at sight glass.
  • Check coolant level and ensure cap is secure.
  • Drain water from fuel separator.
  • Check DEF level.
  • Check air filter restriction indicator.
Every 250 h
  • Change engine oil and filter.
  • Grease all points (boom, stick, bucket, swing bearing).
  • Check fluid levels.
  • Check air filter element.
  • Inspect belts and hoses.
  • Perform visual walk-around for leaks.
Every 500 h
  • Change engine oil and filter.
  • Replace fuel filter.
  • Replace hydraulic return filter.
  • Test battery and alternator.
  • Test coolant SCA.
  • Collect KOWA oil sample.
Every 1,000 h
  • Change engine oil and filter.
  • Clean or replace air filter outer element.
  • Replace hydraulic return filter.
  • Collect KOWA hydraulic oil sample.
  • Inspect turbocharger.
  • Check valve adjustment.
Every 2,000 h
  • Change engine oil and filter.
  • Replace fuel filter.
  • Change hydraulic oil.
  • Flush and replace coolant.
  • Inspect structural components (boom/stick welds).
  • Measure undercarriage wear.

Servicing the 3D72-2GA(S/N 07992-UP) beyond the schedule

Predictive Maintenance & Fluid Analysis

Utilize KOWA fluid analysis at every 500-hour interval to monitor engine wear metals and hydraulic system contamination. Check coolant SCA levels at 500 hours to prevent liner cavitation in the 3D72-2GA block. Monitor hydraulic oil particle counts to protect the main pump and control valves. Track fuel dilution and soot levels in engine oil to determine optimal change intervals based on actual operating conditions rather than fixed hours alone.

Corrective & Common Repairs

Address fuel system issues by inspecting the injection pump and nozzles for leaks or clogging, common in high-hour 3D72-2GA engines. Replace worn turbocharger seals if blue smoke or loss of power occurs. Inspect the water pump and cooling fan for leaks or imbalance. Check the alternator and starter motor mounts for vibration damage. Replace hydraulic hoses showing cracks or abrasion to prevent system failure and contamination.

Overhaul & Rebuild Points

Plan engine overhaul when compression drops below specification or oil consumption exceeds limits. Replace cylinder liners, pistons, and rings as a set to restore compression in the 3D72-2GA. Inspect the crankshaft for wear and replace bearings if clearances are out of spec. Check the camshaft and rocker arms for wear. Rebuild the hydraulic pump and control valves if flow or pressure tests indicate internal leakage.

Seasonal & Environment Servicing

In cold weather, ensure coolant concentration prevents freezing and use low-viscosity engine oil for cold starts. In dusty environments, check the air filter restriction indicator more frequently and clean the radiator fins daily. In high-humidity areas, drain the fuel separator daily to prevent water contamination. Inspect the undercarriage for mud buildup that can cause track derailment or excessive wear on rollers and sprockets.

3D72-2GA(S/N 07992-UP) common service parts

Part numberPart
YM102103-55520O-Ring,(For Fuel Filter)Check fitment →
YM119632-55620Fuel Filter Ass'YCheck fitment →
YM124550-55700Element,Fuel FilterCheck fitment →
YM171051-92760Wrench,Fuel Filter? Water SeparatorCheck fitment →
YM121465-12510Element,Air CleanerCheck fitment →

Always confirm against your machine's serial number — cross-check any part in Heavy Parts AI before ordering.

3D72-2GA(S/N 07992-UP) fault codes & troubleshooting

CodeMeaningLikely causeWhat to do
CA115Engine crankshaft speed sensor failureBroken sensor, wiring issue, or connector corrosionReplace the speed sensor and verify the voltage at the pin connector
CA111Internal engine controller faultECM internal abnormalityReplace or reprogram the ECM
CA451Common rail pressure sensor feedback value too highMalfunction in the rail sensor or actual overpressure conditionDiagnose the fuel rail pressure sensor or pump lines
CA234Engine overspeedThrottle calibration error, engine load cycle issue, or operator misuseVerify throttle calibration and engine load cycle
CA441Battery voltage too lowAlternator failure, battery issue, or voltage regulator faultReplace the alternator or battery; check the voltage regulator
CA442Battery voltage too highAlternator overcharging or voltage regulator failureReplace the alternator or battery; check the voltage regulator
AA10NXAir cleaner cloggingDirty or blocked air filter elementReplace the air filter
B@BCNSEngine coolant overheatingRadiator blockage, fan belt failure, or low coolant levelCheck radiator fins, fan belt, and coolant level
B@HANSHydraulic oil overheatingContaminated hydraulic oil, clogged filter, or cooler fan failureChange hydraulic filter and oil; check cooler fan
AB00KECharging voltage too lowAlternator malfunction or loose beltReplace the alternator or tighten the belt

Codes and remedies are general guidance for this model family — always confirm with diagnostic tooling and your dealer before major repairs.

3D72-2GA(S/N 07992-UP) attachments & work tools

Standard Buckets

Typical capacities for this class range from 0.15 to 0.25 m³ (0.20 to 0.33 cu yd). The machine utilizes a standard pin-on coupler system compatible with common mini-excavator bucket widths.

Tilt Rotator Attachments

Compatible with hydraulic tilt rotators requiring a dual-flow auxiliary circuit. Factory configurations often include a quick-attach plate to facilitate rapid tool changes without hydraulic disconnection.

Hydraulic Breakers

Suitable for breakers up to 1.5 tons. Requires a high-flow hydraulic kit and a specific mounting bracket. The 3D72-2GA engine provides sufficient power for standard duty cycles in this size class.

Augers

Post-hole augers are available in diameters from 300 to 600 mm (12 to 24 in). These tools require a dedicated hydraulic motor kit and a mounting frame compatible with the standard quick-attach interface.

Forks and Grapples

Pallet forks and material grapples are offered for material handling tasks. These attachments typically use the standard pin-on mount and do not require auxiliary hydraulic lines for basic operation.

All 3D72-2GA(S/N 07992-UP) assemblies by section

Every catalogued assembly group for the Komatsu 3D72-2GA(S/N 07992-UP). Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.

Cooling System
Komatsu : 3d72-2ga(S/N 07992-Up) : Cooling System : Water Pump And Cooling Fan
YM***20O-Ring1
YM***02Bolt Plated2
YM***04Water Pump Ass'Y1
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Cylinder Block
Komatsu : 3d72-2ga(S/N 07992-Up) : Cylinder Block : Camshaft And Tappet
YM***00Gear,Camshaft1
YM***00Rod,Push6
YM***50Retainer, Bearing1
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Komatsu : 3d72-2ga(S/N 07992-Up) : Cylinder Block : Crankshaft
YM***80Bolt1
YM***41Washer1
YM***20Wrench1
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Komatsu : 3d72-2ga(S/N 07992-Up) : Cylinder Block : Cylinder Block
YM***11Gauge,Level1
YM***20Plug,Drain(Without Oil Cooler Type)1
YM***00Main Metal Ass'Y (Std)4
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Komatsu : 3d72-2ga(S/N 07992-Up) : Cylinder Block : Flywheel And Flywheel Housing
YM***20Bolt Plated3
YM***52Bolt6
YM***90Flywheel Ass'Y1
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Komatsu : 3d72-2ga(S/N 07992-Up) : Cylinder Block : Front Cover And Gear
YM***22Retainer, Idle Gear1
YM***51Cap, Lub. Oil Supply1
YM***92Case,Gear1
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Komatsu : 3d72-2ga(S/N 07992-Up) : Cylinder Block : Oil Pan
YM***50O-Ring1
YM***52Bolt Plated20
YM***40O-Ring,Drain Plug1
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Komatsu : 3d72-2ga(S/N 07992-Up) : Cylinder Block : Piston And Connecting Rod
YM***10Crank Pin Metal A.,0.25mm (Us)1
YM***00Connecting Rod, Assembly3
YM***01Piston Ring Ass'Y1
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Cylinder Head
Komatsu : 3d72-2ga(S/N 07992-Up) : Cylinder Head : Air Intake Manifold And Air Cleaner
YM***10Cap1
YM***51Pipe,Suction1
YM***80Bolt,Wing1
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Komatsu : 3d72-2ga(S/N 07992-Up) : Cylinder Head : Cylinder Head
YM***80Retainer, Spring6
YM***00Bolt,Head14
YM***10Valve,Exhaust3
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Komatsu : 3d72-2ga(S/N 07992-Up) : Cylinder Head : Cylinder Head Cover
YM***00Pipe,Breather1
YM***51Cap, Lub. Oil Supply1
YM***31Gasket,Plate (Kit)1
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Komatsu : 3d72-2ga(S/N 07992-Up) : Cylinder Head : Exhaust Manifold And Muffler
YM***02Screw4
YM***22Stud4
YM***10Gasket,Exhaust Manifold (Kit)1
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Komatsu : 3d72-2ga(S/N 07992-Up) : Cylinder Head : Rocker Arm
YM***30Screw,Adjusting2
YM***62Screw1
YM***02Nut2
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Electrical System
Komatsu : 3d72-2ga(S/N 07992-Up) : Electrical System : Alternator
YM***00Stator Ass'Y1
YM***10Bearing,Ball1
YM***02Alternator A. (20a)1
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Komatsu : 3d72-2ga(S/N 07992-Up) : Electrical System : Alternator And Mounting
YM***02Screw1
YM***62Bolt,(For Shipping)1
YM***52Screw1
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Komatsu : 3d72-2ga(S/N 07992-Up) : Electrical System : Forwarded Individually Parts (Electrical Parts)
YM***21Indicator, Charging1
YM***00Feed Pump Ass'Y1
YM***11Limiter, Current1
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Komatsu : 3d72-2ga(S/N 07992-Up) : Electrical System : Starting Motor
YM***01Washer,Spring1
YM***20Cover1
YM***51Nut1
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Komatsu : 3d72-2ga(S/N 07992-Up) : Electrical System : Starting Motor And Mounting
YM***52Bolt Plated2
(Y***1)Starting Motor Ass'Y,(See Fig.A6210-B0a1)1
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Fuel System
Komatsu : 3d72-2ga(S/N 07992-Up) : Fuel System : Engine Stop Motor And Mounting
YM***80Ring,Snap1
YM***00Pin,Cotter1
YM***20Spring1
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Komatsu : 3d72-2ga(S/N 07992-Up) : Fuel System : Fuel Filter And Piping
YM***40Lever1
YM***00O-Ring (Kit)1
YM***31Hose Ass'Y,Fuel1
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Komatsu : 3d72-2ga(S/N 07992-Up) : Fuel System : Fuel Injection Pump
YM***00Valve W/Seat, Deliv3
YM***00Washer,Spring2
YM***00Washer2
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Komatsu : 3d72-2ga(S/N 07992-Up) : Fuel System : Fuel Injection Pump And Piping
YM***20Retainer, Pipe1
YM***21Pipe,Injection? No.21
YM***50Shim Ass'Y1
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Komatsu : 3d72-2ga(S/N 07992-Up) : Fuel System : Fuel Nozzle And Spill Pipe
YM***40Spacer, Valve Stop3
YM***20Wire,Glow Plug1
YM***00Sleeve3
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Komatsu : 3d72-2ga(S/N 07992-Up) : Fuel System : Governor
YM***50Nut,Lock1
YM***00Pin, Cotter1
YM***00Retainer, Shaft1
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Komatsu : 3d72-2ga(S/N 07992-Up) : Fuel System : Water Separator
YM***00Gasket2
YM***00O-Ring (Kit)1
YM***50Plug,Air2
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Lubricating Oil System
Komatsu : 3d72-2ga(S/N 07992-Up) : Lubricating Oil System : Lubricating Oil Filter
YM***50Nut1
YM***02Bolt Plated3
YM***51Cartridge1
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Komatsu : 3d72-2ga(S/N 07992-Up) : Lubricating Oil System : Lubricating Oil Pump
YM***50Oil Pressure Transmitter1
YM***91Pipe,Oil Inlet1
YM***20O-Ring,Cylinder Head Cover Bolt1
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Tool And Kit
Komatsu : 3d72-2ga(S/N 07992-Up) : Tool And Kit : Gasket Kit
YM***11Gasket (Kit)1
YM***40Gasket,Head (Kit)1
YM***10Gasket,Exhaust Manifold (Kit)1
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Komatsu : 3d72-2ga(S/N 07992-Up) : Tool And Kit : Tool
YM***60Wrench,Fuel Filter? Water Separator1
YM***50Screw Driver1
YM***00Tool Ass'Y,(Pc38uu)1
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Frequently asked questions

What engine does the Komatsu 3D72-2GA use?

The Komatsu 3D72-2GA is a diesel engine powering the PC05-5, PC05-6, PC05-7, and PC07-1 excavator series.

What is the operating weight of the Komatsu 3D72-2GA machine?

Operating weight varies by configuration and undercarriage setup, typically ranging from 5,000 to 7,500 kg (11,000 to 16,500 lb).

What replaced the Komatsu 3D72-2GA machine?

The PC07-2 and PC10-5 series excavators succeeded the PC05-5/PC07-1 line, featuring updated engines and emissions systems.

What 3D72-2GA(S/N 07992-UP) owners discuss

What engine powers the Komatsu 3D72-2GA(S/N 07992-UP) and what are its known quirks?
The Komatsu 3D72-2GA engine is a direct variant of the Yanmar 3TN72 series. Owners and mechanics note that while the engine is mechanically robust, it requires strict adherence to fuel quality standards. Common quirks include sensitivity to water in the fuel system, which can cause hard starting or rough idle, and a tendency for the fuel injection pump to develop internal wear if low-quality or contaminated diesel is used. The engine is compact, which can make access to certain service points tight during routine maintenance.
What are the typical hydraulic behaviors and common failure points for this machine type?
Komatsu excavators of this class rely on a load-sensing hydraulic system. A common consensus among operators is that hydraulic performance degrades gradually rather than failing suddenly. The most frequent issues involve the main control valve spools wearing over time, leading to slow or imprecise movements. Additionally, the hydraulic pump is often cited as a wear item; if the pump fails, it frequently damages the engine crankshaft or mounts, which is a known design characteristic of this series. Operators should monitor hydraulic oil temperature closely, as overheating can lead to accelerated seal failure and loss of pressure.
What undercarriage or wear patterns are typical for this machine type?
Undercarriage wear is heavily dependent on the operating surface. In rocky or abrasive conditions, track shoes, idlers, and sprockets wear out rapidly. A common pattern noted by mechanics is uneven track wear due to improper tension or binding in the final drives. The final drives themselves are known to be robust but can leak seals if the machine is operated in deep mud or water frequently. Regular inspection of track tension and roller condition is essential to prevent premature wear of the track chain and undercarriage components.
What are common electrical or sensor issues reported by owners?
Owners frequently report intermittent electrical issues related to the machine's electronic control unit (ECU) and sensor network. Common problems include faulty coolant temperature sensors triggering false overheating warnings, and issues with the main harness connectors corroding or coming loose, leading to random shutdowns or dashboard failures. Grounding points can also corrode, causing erratic behavior in the hydraulic controls and starting system. Ensuring clean, tight electrical connections is a critical maintenance step.
What should be checked when buying a used Komatsu 3D72-2GA(S/N 07992-UP)?
When purchasing a used machine with this serial range, buyers should prioritize checking the hydraulic pump for internal leakage by testing pressure under load. Inspect the engine for signs of excessive blow-by or oil consumption, which may indicate worn piston rings or cylinder liners. Check the undercarriage for uneven wear and verify that the final drives do not leak. Additionally, test all hydraulic functions for smooth operation and check for any stored fault codes in the ECU that may indicate intermittent electrical issues.
What safety-critical fix is associated with the hydraulic system on this series?
The main safety valve and hydraulic system pressure regulation are critical for safe operation. If the hydraulic system loses pressure or the swing brake fails to hold, the machine can drift or collapse unexpectedly. Have your dealer verify the swing brake holding capacity and the main relief valve settings to ensure they meet factory specifications. Failure to maintain these components can lead to catastrophic failure of the upper structure or hydraulic lines.

Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.

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