Komatsu S4D155-4(S/N 10287-50040)
Maintenance schedule, common problems & OEM parts breakdown
The Komatsu S4D155-4 is a four-cylinder, turbocharged diesel engine designed for heavy-duty applications. It powers the D155 series crawler dozers, including the D155A, D155S, D155W, and D155C models. The engine is rated at 354 net horsepower (264 kW) at 1900 rpm. It is used in machines with operating weights ranging from approximately 89,300 lb (40,506 kg) for the D155AX-8 to heavier configurations. Production years for the D155 series span from the late 1990s through the 2010s. The S4D155-4 succeeded earlier S4D155 variants and was later replaced by emissions-compliant engines in the D155AX-8 generation. Configurations offered include standard and wide-track undercarriage options, with the engine adapted for various regional emissions standards.
Across generations, the S4D155-4 evolved to meet stricter emissions regulations, transitioning from Tier 2/3 to Tier 4 Final standards. The -4 designation indicates the fourth generation of the S4D155 series, featuring updated fuel injection and turbocharging systems. This engine matters in the used and parts market because it is a high-horsepower unit found in large dozers that are still active in mining and heavy earthmoving. Its four-cylinder design offers a balance of power and compactness, making it a common target for rebuilds and component swaps. The S4D155-4 is distinct from the S4D102E series, which powers smaller dozers, and shares some architecture with the S6D155-4 six-cylinder variant but has unique four-cylinder components.
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 S4D155-4(S/N 10287-50040) specifications
Engine
| Model | S4D155-4 |
| Series | 155-4 Series |
| Displacement | 12.840 L (783.5 cu in) |
| Cylinders | 4 |
| Arrangement | In-line, turbocharged |
| Bore | 155.0 mm (6.10 in) |
| Stroke | 170.0 mm (6.69 in) |
| Power | 156–178 kW (210–240 hp) @ 1850 rpm |
| Emissions Tier | Tier 4 Final / Stage V |
Weights
| Engine Weight | approx. 2050 kg (4519 lb) |
Dimensions
| Engine Length | approx. 1456 mm (57.3 in) |
| Engine Width | approx. 1125 mm (44.3 in) |
| Engine Height | approx. 1910 mm (75.2 in) |
Performance
| Note | Machine performance figures (travel speed, lift capacity, etc.) are not documented for the S4D155-4 engine in the provided sources; these values depend on the host machine configuration. |
Service capacities (summary)
| Note | Specific fluid capacities for the S4D155-4 engine are not provided in the source text; refer to the Komatsu shop manual SEBE6120A05 or the host machine's O&M manual for first-fill and refill capacities. |
Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.
Komatsu S4D155-4(S/N 10287-50040) maintenance schedule
| Service interval | Tasks |
|---|---|
| Every 10 h |
|
| Every 250 h |
|
| Every 500 h |
|
| Every 1,000 h |
|
| Every 2,000 h |
|
Servicing the S4D155-4(S/N 10287-50040) beyond the schedule
Predictive Maintenance & Fluid Analysis
Monitor KOWA oil samples at every 500-hour interval to track wear metals and contamination. Check coolant SCA levels at 500 hours to ensure corrosion protection. Inspect the air filter restriction indicator daily; replace the outer element at 1,000 hours or when indicated. Verify hydraulic oil cleanliness via particle count during 1,000-hour services. Use Komatsu Genuine Lubricants to maintain viscosity and additive packages. Track fuel dilution and soot levels in engine oil to predict injector or turbocharger issues early.
Corrective & Common Repairs
Address fuel filter clogging by replacing the primary filter at 500 hours to prevent injector damage. Inspect turbocharger shaft play and housing for cracks during 1,000-hour services. Check belt tension and hose condition at 250 hours to prevent overheating or loss of drive. Replace worn piston rings and cylinder liners if compression drops or oil consumption increases. Inspect the fuel injection pump for leaks and adjust valve clearances as specified. Replace worn turbocharger seals to prevent oil leakage into the intake or exhaust.
Overhaul & Rebuild Points
Plan major overhaul at 10,000 to 15,000 hours depending on duty cycle. Replace cylinder head gaskets and inspect the cylinder head for warpage. Rebuild the turbocharger if boost pressure is inconsistent or oil consumption is high. Replace the fuel injection pump and injectors if performance drops below spec. Inspect the crankshaft for wear and replace bearings if clearances exceed limits. Rebuild the water pump if leaks or bearing noise are detected. Ensure all gaskets and seals are replaced during overhaul to prevent future leaks.
Seasonal & Environment Servicing
In cold climates, use low-temperature coolant and check battery health frequently. Drain the fuel water separator daily to prevent freezing and injector issues. In dusty environments, check the air filter more frequently and replace the inner element as needed. In high-temperature environments, clean the radiator and oil cooler fins daily to prevent overheating. Inspect hoses and belts for UV damage and cracking. Use Komatsu Super Coolant AF-NAC for extended life and corrosion protection in all seasons.
S4D155-4(S/N 10287-50040) common service parts
| Part number | Part | Notes | |
|---|---|---|---|
| 6110-73-6101 | Fuel Filter Ass'Y | Fuel system service | Check fitment → |
| 6127-71-6100 | Fuel Filter Ass'Y | Fuel system service | Check fitment → |
| 6124-71-6510 | Damper,Fuel Filter | Fuel system service | Check fitment → |
| 6127-21-6521 | Gasket,Oil Filter | Lubrication service | Check fitment → |
| 6120-51-5180 | Gasket,Oil Filter | Lubrication service | Check fitment → |
Always confirm against your machine's serial number — cross-check any part in Heavy Parts AI before ordering.
S4D155-4(S/N 10287-50040) fault codes & troubleshooting
| Code | Meaning | Likely cause | What to do |
|---|---|---|---|
| CA115 | Engine crankshaft speed sensor and backup speed sensor failure | Faulty speed sensor, damaged wiring harness, or corroded connector at the sensor pin | Inspect sensor wiring and connectors; replace the speed sensor if voltage is abnormal at the pin connector |
| CA111 | Internal engine controller (ECM) fault | Critical internal failure of the Electronic Control Module | Replace or reprogram the ECM |
| CA451 | Common rail pressure sensor feedback value too high | Malfunctioning rail pressure sensor or actual overpressure condition in the fuel system | Diagnose the fuel rail pressure sensor and check pump lines for blockage or leakage |
| CA452 | Common rail pressure sensor feedback value too low | Malfunctioning rail pressure sensor or low fuel pressure | Diagnose the fuel rail pressure sensor and check pump lines |
| CA122 | Intake air pressure sensor feedback voltage too high | Faulty intake pressure sensor or wiring issue | Verify the intake pressure sensor operation and inspect wiring integrity |
| CA123 | Intake air pressure sensor feedback voltage too low | Sensor short circuit or airflow restriction upstream of the sensor | Check for a sensor short or inspect for airflow restrictions |
| CA153 | Intake air temperature sensor feedback voltage too high | Faulty Intake Air Temperature (IAT) sensor | Replace or test the IAT sensor |
| CA154 | Intake air temperature sensor feedback voltage too low | Faulty Intake Air Temperature (IAT) sensor | Replace or test the IAT sensor |
| CA441 | Battery voltage too low | Weak battery, failing alternator, or loose connections | Replace the alternator or battery; check the voltage regulator and connections |
| CA442 | Battery voltage too high | Failing voltage regulator or alternator overcharging | Replace the alternator or battery; check the voltage regulator |
Codes and remedies are general guidance for this model family — always confirm with diagnostic tooling and your dealer before major repairs.
S4D155-4(S/N 10287-50040) attachments & work tools
Bulldozer Blade Systems
The S4D155-4 engine powers the D155 series crawler dozers, which utilize large capacity blade configurations. Factory specifications for the D155AX-8 include a SIGMA Douser blade with a capacity of 11.9 m³ (15.6 yd³) and a Full-U blade capacity of 9.4 m³ (12.3 yd³). These attachments are mounted via a standard dozer frame interface and require high-flow hydraulic circuits for tilt and angle control.
Industrial & Marine Engine Applications
The S4D155-4 is a four-cylinder industrial engine variant within the 155-4 series, distinct from the six-cylinder S6D155-4 used in larger excavators and dozers. It is typically configured for stationary power generation sets (such as the EG300 series) or marine propulsion, where it is mounted to engine cradles or transmission housings rather than earthmoving work tools. No standard hydraulic work tool couplers are applied to this engine platform.
Hydraulic System Configurations
Work tool compatibility for the S4D155-4 is defined by its application in industrial or marine settings rather than mobile construction equipment. For generator applications, the engine is coupled to an alternator via a flexible coupling or direct drive shaft. Hydraulic requirements are limited to engine-mounted accessories such as the oil pump and fuel injection pump, which utilize Komatsu standard hydraulic oil (HO) and diesel engine oil (TO) specifications.
All S4D155-4(S/N 10287-50040) assemblies by section
Every catalogued assembly group for the Komatsu S4D155-4(S/N 10287-50040). Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.
Cooling System
Komatsu : S4d155-4(S/N 10287-50040) : Cooling System : Cooling Fan And Fan Drive(#10287-)
| 01***20 | Bolt,(Sandy? Dusty Terrain Spec.) | 7 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 2 |
| 01***30 | Bolt,Radio Controlled Slag Handling | 3 |
Komatsu : S4d155-4(S/N 10287-50040) : Cooling System : Corrosion Resistor(#50279-)
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 1 |
| 01***25 | Bolt - Rear Guard Mounting | 2 |
| 01***08 | Nut, Regular Hexagon (M10-1.50) | 1 |
Komatsu : S4d155-4(S/N 10287-50040) : Cooling System : Dynamo And Mounting(#10287-)
| 01***11 | Nut | 1 |
| 01***36 | Washer,Radio Controlled Slag Handling | 3 |
| 01***54 | Washer,(For Slag Handling) | 1 |
Komatsu : S4d155-4(S/N 10287-50040) : Cooling System : Dynamo(#10287-)
| 60***10 | Dynamo Ass'Y (20a) | 1 |
| KD***40 | Rear Bracket Ass'Y | 1 |
| KD***50 | Washer | 1 |
Komatsu : S4d155-4(S/N 10287-50040) : Cooling System : Regulator And Safety Relay(#10287-)
| 60***02 | Safety Relay Ass'Y | 1 |
| 60***10 | Regulator Ass'Y,(For 800w Alternator) | 1 |
| 60***20 | Safety Relay Ass'Y | 1 |
Komatsu : S4d155-4(S/N 10287-50040) : Cooling System : Starting Motor And Mounting(#10287-)
| 01***25 | Bolt - Rear Guard Mounting | 2 |
| 01***45 | Bolt,(For Slag Handling) | 3 |
| 01***25 | Bolt | 2 |
Komatsu : S4d155-4(S/N 10287-50040) : Cooling System : Starting Motor(#10287-)
| 60***51 | Starting Motor A.,(11kw) | 1 |
| 60***52 | Starting Motor Ass'Y,(11kw) | 1 |
| 60***53 | Starting Motor Ass'Y,(11kw) | 1 |
Komatsu : S4d155-4(S/N 10287-50040) : Cooling System : Water Pump And Piping(#10287-)
| 01***15 | Bolt | 6 |
| 01***20 | Bolt,(Sandy? Dusty Terrain Spec.) | 4 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 2 |
Cylinder Block
Komatsu : S4d155-4(S/N 10287-50040) : Cylinder Block : Balancer(#10287-)
| 04***19 | Key,(Dk025805-1910) | 2 |
| 61***30 | Plug, No. 4 | 4 |
| 61***41 | Bushing | 10 |
Komatsu : S4d155-4(S/N 10287-50040) : Cylinder Block : Camshaft And Tappet(#10287-)
| 04***35 | Key | 1 |
| 61***30 | Plug, No. 4 | 1 |
| 61***10 | Camshaft Ass'Y | 1 |
Komatsu : S4d155-4(S/N 10287-50040) : Cylinder Block : Crankshaft And Vibration Damper(#10287-)
| 01***30 | Bolt | 6 |
| 01***36 | Washer,Radio Controlled Slag Handling | 6 |
| 02***04 | Plug,(For Shipping) | 4 |
Komatsu : S4d155-4(S/N 10287-50040) : Cylinder Block : Cylinder Block(#10287-)
| 01***25 | Bolt | 8 |
| 01***18 | Bolt | 4 |
| 01***20 | Bolt,(Large Capacity Type) (Std) | 1 |
Komatsu : S4d155-4(S/N 10287-50040) : Cylinder Block : Flywheel And Housing(#10287-)
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 8 |
| 01***30 | Bolt,(For France Noise Suppression) | 12 |
| 01***45 | Bolt, Mount Bracket | 4 |
Komatsu : S4d155-4(S/N 10287-50040) : Cylinder Block : Gear Case And Front Suppor(#10287-)
| 01***12 | Bolt,(Without R.P.C.U.) | 2 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 10 |
| 01***90 | Bolt (M10-1.50x90) | 8 |
Komatsu : S4d155-4(S/N 10287-50040) : Cylinder Block : Oil Pan(#10287-)
| 01***20 | Bolt,(Sandy? Dusty Terrain Spec.) | 1 |
| 01***25 | Bolt,(Without Auto Priming System) | 2 |
| 01***20 | Bolt,(Large Capacity Type) (Std) | 10 |
Komatsu : S4d155-4(S/N 10287-50040) : Cylinder Block : Piston And Connecting Rod(#10287-)
| 61***20 | Ring,Snap | 1 |
| 61***10 | Piston Ass'Y | 4 |
| 61***21 | Piston Ring Ass'Y | 1 |
Komatsu : S4d155-4(S/N 10287-50040) : Cylinder Block : Power Take Off(#10287-)
| 01***20 | Bolt,(Large Capacity Type) (Std) | 6 |
| 01***30 | Bolt,(For France Noise Suppression) | 6 |
| 01***30 | Bolt,Radio Controlled Slag Handling | 6 |
Cylinder Head
Komatsu : S4d155-4(S/N 10287-50040) : Cylinder Head : Air Cleaner And Pre-Cleaner(#10287-)
| 01***35 | Bolt, Mounting - Flywheel Housing End | 2 |
| 01***08 | Nut, Regular Hexagon (M10-1.50) | 1 |
| 01***30 | Washer,Spring(Sandy?Dusty Terrain S.) | 8 |
Komatsu : S4d155-4(S/N 10287-50040) : Cylinder Head : Air Intake Manifold And Connection(#10287-)
| 01***30 | Bolt,(Cold Terrain Spec.) | 4 |
| 01***20 | Bolt,(Large Capacity Type) (Std) | 2 |
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 12 |
Komatsu : S4d155-4(S/N 10287-50040) : Cylinder Head : Compression Release(#10287-)
| 01***30 | Bolt,(Cold Terrain Spec.) | 1 |
| 01***25 | Washer,Spring?(Sandy And Dusty Spec.) | 3 |
| 04***20 | Key | 1 |
Komatsu : S4d155-4(S/N 10287-50040) : Cylinder Head : Cylinder Head(#10287-)
| 01***30 | Bolt,(For France Noise Suppression) | 4 |
| 01***30 | Washer,Spring(Sandy?Dusty Terrain S.) | 4 |
| 07***20 | Plug | 13 |
Komatsu : S4d155-4(S/N 10287-50040) : Cylinder Head : Exhaust Manifold And Muffler(#10287-10310)
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 4 |
| 01***10 | Bolt | 12 |
| 01***20 | Bolt | 1 |
Komatsu : S4d155-4(S/N 10287-50040) : Cylinder Head : Exhaust Manifold And Muffler(#10311-10311)
| 01***10 | Bolt | 12 |
| 01***20 | Bolt | 1 |
| 01***11 | Nut (M14-1.50 Thd), Nut; Was 01582-01411 | 2 |
Komatsu : S4d155-4(S/N 10287-50040) : Cylinder Head : Exhaust Manifold And Muffler(#10312-10312)
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 4 |
| 01***10 | Bolt | 12 |
| 01***20 | Bolt | 1 |
Komatsu : S4d155-4(S/N 10287-50040) : Cylinder Head : Exhaust Manifold And Muffler(#10313-10313)
| 01***10 | Bolt | 12 |
| 01***20 | Bolt | 1 |
| 01***11 | Nut (M14-1.50 Thd), Nut; Was 01582-01411 | 2 |
Komatsu : S4d155-4(S/N 10287-50040) : Cylinder Head : Exhaust Manifold And Muffler(#10314-)
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 4 |
| 01***50 | Bolt | 1 |
| 01***10 | Bolt | 12 |
Komatsu : S4d155-4(S/N 10287-50040) : Cylinder Head : Rocker Arm And Housing(#10287-)
| 01***05 | Bolt (Kit) | 14 |
| 01***10 | Bolt, Mount Filler Tube | 3 |
| 01***25 | Washer,Spring?(Sandy And Dusty Spec.) | 1 |
Komatsu : S4d155-4(S/N 10287-50040) : Cylinder Head : Rocker Arm Housing Cover(#10287-)
| 01***22 | Bolt,(Cold Terrain Spec.) | 3 |
| 01***40 | Bolt,(For Position Fixing) | 2 |
| 01***75 | Bolt,(For D57sr) | 10 |
Komatsu : S4d155-4(S/N 10287-50040) : Cylinder Head : Turbocharger(#10287-10310)
| 01***30 | Bolt | 4 |
| 01***18 | Bolt | 6 |
| 01***08 | Washer,Lock (Kit) | 8 |
Komatsu : S4d155-4(S/N 10287-50040) : Cylinder Head : Turbocharger(#10312-10312)
| 01***30 | Bolt | 4 |
| 01***18 | Bolt | 6 |
| 01***08 | Washer,Lock (Kit) | 8 |
Komatsu : S4d155-4(S/N 10287-50040) : Cylinder Head : Turbocharger(#10314-)
| 01***30 | Bolt | 4 |
| 01***18 | Bolt | 6 |
| 01***08 | Washer,Lock (Kit) | 8 |
Komatsu : S4d155-4(S/N 10287-50040) : Cylinder Head : Water Manifold And Thermostat(#10287-)
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 4 |
| 01***30 | Bolt,(For France Noise Suppression) | 12 |
| 01***35 | Bolt, Mounting - Flywheel Housing End | 8 |
Fuel System
Komatsu : S4d155-4(S/N 10287-50040) : Fuel System : Feed Pump(#10287-)
| 02***04 | Plug,(Not Shown) | 1 |
| 61***31 | Joint | 1 |
| DK***20 | Case,Filter | 1 |
Komatsu : S4d155-4(S/N 10287-50040) : Fuel System : Fuel Filter(#10287-50156)
| 07***13 | Gasket (K2) | 1 |
| 07***12 | Gasket,Mechanical Pump Piping | 2 |
| 07***12 | Washer, Gasket,(Without Thermo Sensor) (K1) | 1 |
Komatsu : S4d155-4(S/N 10287-50040) : Fuel System : Fuel Filter(#50157-)
| 04***12 | Wire,Lock | 2 |
| 07***12 | Gasket,Mechanical Pump Piping | 4 |
| 07***12 | Washer, Gasket,(Without Thermo Sensor) (K1) | 1 |
Komatsu : S4d155-4(S/N 10287-50040) : Fuel System : Fuel Injection Pump And Piping(#10287-)
| 01***12 | Bolt (M8-1.25x12) | 1 |
| 01***20 | Bolt,(Sandy? Dusty Terrain Spec.) | 3 |
| 01***25 | Bolt,(Without Auto Priming System) | 4 |
Komatsu : S4d155-4(S/N 10287-50040) : Fuel System : Fuel Injection Pump Drive(#10287-)
| 01***30 | Bolt,Radio Controlled Slag Handling | 6 |
| 01***35 | Bolt - Torque Converter Totransmission Mounting | 1 |
| 01***30 | Bolt,(Cold Weather Spec.) | 6 |
Komatsu : S4d155-4(S/N 10287-50040) : Fuel System : Fuel Injection Pump(#10287-)
| 61***23 | Injection Pump Ass'Y | 1 |
| 61***24 | Injection Pump Ass'Y | 1 |
| DK***12 | Block Ass'Y | 4 |
Komatsu : S4d155-4(S/N 10287-50040) : Fuel System : Fuel Nozzle And Spill Pipe(#10287-)
| 07***12 | Gasket,Mechanical Pump Piping | 16 |
| 61***11 | Pipe | 4 |
| 61***03 | Nozzle Holder Ass'Y | 4 |
Komatsu : S4d155-4(S/N 10287-50040) : Fuel System : Governor(#10287-)
| DK***30 | Spring,Torque | 1 |
| DK***19 | Shim? 0.40mm | 0 |
| DK***64 | Gasket | 1 |
Komatsu : S4d155-4(S/N 10287-50040) : Fuel System : Thermostart And Piping(#10311-10311)
| 01***25 | Bolt | 1 |
| 01***12 | Bolt | 2 |
| 01***16 | Bolt | 3 |
Komatsu : S4d155-4(S/N 10287-50040) : Fuel System : Thermostart And Piping(#10313-10313)
| 01***25 | Bolt | 1 |
| 01***12 | Bolt | 2 |
| 01***16 | Bolt | 3 |
Komatsu : S4d155-4(S/N 10287-50040) : Fuel System : Timer(#10287-)
| DK***07 | Shim? 1.0mm | 0 |
| DK***00 | Nut | 1 |
| DK***04 | Shim | 0 |
Lubricating Oil System
Komatsu : S4d155-4(S/N 10287-50040) : Lubricating Oil System : Camshaft Lubricating Oil Piping(#10287-)
| 07***10 | Connector,Pipe | 3 |
| 07***10 | Elbow | 1 |
| 61***50 | Nozzle | 2 |
Komatsu : S4d155-4(S/N 10287-50040) : Lubricating Oil System : Lubricating Bypass Filter(#50279-)
| 02***32 | Bolt | 2 |
| 02***20 | Washer,Spring | 2 |
| 02***01 | O-Ring (Kit) | 1 |
Komatsu : S4d155-4(S/N 10287-50040) : Lubricating Oil System : Lubricating Oil Cooler(#10287-)
| 01***12 | Bolt (M8-1.25x12) | 2 |
| 01***30 | Bolt,(For France Noise Suppression) | 8 |
| 01***35 | Bolt, Mounting - Flywheel Housing End | 24 |
Komatsu : S4d155-4(S/N 10287-50040) : Lubricating Oil System : Lubricating Oil Filter(#10287-)
| 01***30 | Bolt,(For France Noise Suppression) | 4 |
| 01***35 | Bolt - Torque Converter Totransmission Mounting | 6 |
| 01***04 | Nut | 2 |
Komatsu : S4d155-4(S/N 10287-50040) : Lubricating Oil System : Lubricating Oil Pump(#10287-)
| 01***25 | Bolt,(Sandy? Dusty Terrain Spec.) | 2 |
| 01***55 | Bolt,(For Suction? Reversible Fan) | 2 |
| 01***50 | Bolt - Torque Converter Totransmission Mounting | 2 |
Komatsu : S4d155-4(S/N 10287-50040) : Lubricating Oil System : Lubricating Oil Strainer(#10287-)
| 01***12 | Bolt,(Without R.P.C.U.) | 2 |
| 01***14 | Bolt | 2 |
| 01***16 | Bolt,(For Slag Handling) | 1 |
Komatsu : S4d155-4(S/N 10287-50040) : Lubricating Oil System : Pto Lubricating Oil Piping(#10287-)
| 01***30 | Bolt,(For France Noise Suppression) | 2 |
| 01***20 | Bolt,(Used When Towing Winch) | 2 |
| 01***30 | Washer,Spring(Sandy?Dusty Terrain S.) | 2 |
Komatsu : S4d155-4(S/N 10287-50040) : Lubricating Oil System : Torque Convertor Oil Cooler(#10287-)
| 01***10 | Bolt | 4 |
| 01***25 | Bolt | 15 |
| 01***35 | Bolt | 5 |
Komatsu : S4d155-4(S/N 10287-50040) : Lubricating Oil System : Turbochager Lubricating Oil Piping(#10287-)
| 01***25 | Bolt | 2 |
| 01***30 | Bolt | 2 |
| 01***10 | Bolt | 2 |
Tool And Kit
Komatsu : S4d155-4(S/N 10287-50040) : Tool And Kit : Kit(#10287-)
| 01***12 | Washer,Lock (K2) | 3 |
| 01***12 | Washer,Lock (K2) | 4 |
| 01***08 | Washer,Lock (Kit) | 1 |
S4D155-4(S/N 10287-50040) serial number reference
The engine serial number is stamped on the engine block, typically on the left side near the injection pump. The prefix is the first part of the engine model code (e.g., S4D155-4), which identifies the cylinder count and bore series; the subsequent digits are the build sequence.
| Prefix | Identifies | Notes |
|---|---|---|
| S4D155-4 | Engine Model | 4-cylinder inline diesel engine. Serial range 10287–50040. Source: Komatsu 155-4 Series Workshop Manual (S4D155-4 S/N 10287 ~ 50060) and published references catalog (S/N 10287-50040). Note: Workshop manual lists a sub-range 10287–50060; published references lists 10287-50040. Varies by configuration/series. |
| S6D155-4 | Engine Model | 6-cylinder inline diesel engine. Serial range 10011–13161. Source: Komatsu 155-4 Series Workshop Manual (S6D155-4 S/N 10011 ~ 13161). Included in the same shop manual (SEBE6120A05) as the S4D155-4. |
| S6D155G-4 | Engine Model | 6-cylinder inline diesel engine. Serial range 10011 and up. Source: Komatsu Diesel Engine Shop Manual (SEBE6120A05) listing S6D155G-4 with serial 10011 and up. |
| SA6D155-4 | Engine Model | 6-cylinder inline diesel engine. Serial range 10011 and up. Source: Komatsu Diesel Engine Shop Manual (SEBE6120A05) listing SA6D155-4 with serial 10011 and up. |
Frequently asked questions
What engine does the Komatsu D155A-1 use?
The Komatsu D155A-1 uses the S4D155-4 engine, a four-cylinder turbocharged diesel unit.
What is the operating weight of the Komatsu D155AX-8?
The operating weight of the Komatsu D155AX-8 is approximately 89,300 lb (40,506 kg), varying by configuration.
What replaced the Komatsu D155A-1?
The D155A-1 was replaced by the D155AX-8 series, which features updated emissions-compliant engines and modernized undercarriage systems.
What S4D155-4(S/N 10287-50040) owners discuss
What are the known powertrain and hydraulic behaviors for the Komatsu S4D155-4 engine series?
What undercarriage or wear patterns are typical for machines powered by this engine type?
What are the engine quirks per the S4D155-4 series?
What are common electrical or sensor issues for this engine/machine combination?
What to check when buying a used S4D155-4(S/N 10287-50040) machine?
What is the critical safety fix regarding the hydraulic system for this engine/machine?
How does the S4D155-4 engine differ from the S6D155-4 in terms of specifications?
Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.
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