Komatsuengine(no series)

Komatsu S4D95L-1A-C(S/N 48797-UP)

Maintenance schedule, common problems & OEM parts breakdown

The Komatsu S4D95L-1A-C engine powers the PC100-5 and PC120-5 crawler excavator series, which are mid-size machines in the 20,000 to 60,000 lb operating weight class. Production for these specific models spans the late 1990s through the early 2000s. The PC100-5 and PC120-5 succeeded the PC100-4 and PC120-4 series and were later replaced by the PC100-6 and PC120-6 generations. These machines were offered in standard configurations with varying undercarriage widths and attachment options to suit general construction and earthmoving applications.

Across the 95 Series engine lineage, the S4D95L-1A-C represents a mechanical fuel injection era before the widespread adoption of electronic common-rail systems found in later SAA4D95LE variants. This engine matters in the used and parts market because the PC100-5 and PC120-5 remain prevalent in the secondary market due to their durability and simplicity. The S4D95L-1A-C is widely supported by aftermarket rebuild kits and cross-reference parts, making it a cost-effective powertrain option for fleet managers maintaining older mid-size excavators.

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 S4D95L-1A-C(S/N 48797-UP) specifications

Engine

ModelS4D95L-1A-C
SeriesS4D95L-1A, S4D95L-1B, S4D95L-1G (Build 1H)
Displacement2.690 liter (164.1 cu in)
Cylinders4 in line
Bore95 mm (3.74 in)
Stroke95 mm (3.74 in)
Gross Power28 kW (37.5 hp) @ 2450 rpm to 33 kW (45 hp) @ 2800 rpm
Torque155 Nm (114.3 lbf-ft) @ 1300 rpm to 150 Nm (110.6 lbf-ft) @ 2000 rpm
Emissions TierNot documented for this exact serial range — verify with your dealer

Weights

Engine Weight270-285 kg (595-628 lb)
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

Engine Length767-783 mm (30.2-30.8 in)
Engine Width529-598 mm (20.8-23.5 in)
Engine Height750-972 mm (29.5-38.3 in)
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
Ground ClearanceNot documented for this exact serial range — verify with your dealer

Performance

Travel SpeedsNot documented for this exact serial range — verify with your dealer
GradeabilityNot documented for this exact serial range — verify with your dealer
Dig DepthNot documented for this exact serial range — verify with your dealer
Drawbar PullNot 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 S4D95L-1A-C(S/N 48797-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
  • Check fuel level and drain water from separator
  • Check DEF level on Tier 4 machines
  • Check air filter restriction indicator
Every 250 h
  • Change engine oil and filter
  • Grease all points including boom, stick, bucket, and swing bearing
  • Check fluid levels
  • Check air filter outer element
  • Inspect belts, hoses, and clamps
  • Perform visual walk-around inspection
Every 500 h
  • Replace fuel filter and drain water separator
  • Replace hydraulic return filter
  • Test battery and alternator
  • Test coolant SCA
  • Collect KOWA oil sample
  • Perform detailed undercarriage inspection
Every 1,000 h
  • Change hydraulic oil and collect sample
  • Change final drive oil on both sides
  • Inspect turbocharger
  • Check valve adjustment
  • Inspect structural components for wear
  • Measure undercarriage wear
Every 2,000 h
  • Flush and replace coolant
  • Change hydraulic oil
  • Service transmission
  • Perform comprehensive component evaluation
  • Inspect and replace worn belts and hoses
  • Load test battery and alternator

Servicing the S4D95L-1A-C(S/N 48797-UP) beyond the schedule

Predictive Maintenance & Fluid Analysis

Utilize Komatsu KOWA fluid analysis at every 500-hour interval to monitor wear metals and contamination in the S4D95L-1A-C engine. Track iron, copper, and lead levels to detect internal bearing or liner wear early. Analyze hydraulic fluid for particle count and water content to protect the PC100-5 and PC120-5 hydraulic pumps. Monitor coolant pH and SCA concentration to prevent corrosion in the engine block and cylinder head. Use KOMTRAX telematics to track load frequency and fuel consumption trends for the S4D95L-1A-C powertrain.

Corrective & Common Repairs

Address intermittent starting and random shutdowns in the S4D95L-1A-C by inspecting the Electronic Control Module (ECM) and sensor wiring. Replace worn fuel injection components if power loss or excessive fuel usage occurs. Fix exhaust leaks in the cooling system by inspecting cylinder head gaskets and liner seals, as the 95 Series engine lacks replaceable liners. Repair hydraulic hose leaks and check for pin and bushing wear in the undercarriage of the PC100-5 and PC120-5 excavators to maintain track tension and alignment.

Overhaul & Rebuild Points

Perform inframe overhaul on the S4D95L-1A-C engine when wear limits are reached, typically using kits designed for serial numbers 48811 and up. Replace pistons, rings, and rod bushings as the engine block is solid without replaceable liners. Inspect the turbocharger and valve train during major service intervals. For the PC100-5 and PC120-5 undercarriage, measure sprocket, idler, and roller wear to determine replacement timing. Evaluate the hydraulic pump and swing machinery oil for contamination before major component failure.

Seasonal & Environment Servicing

In cold climates, ensure the PC100-5 and PC120-5 use appropriate low-temperature fluids and check the battery health for cold starts. In dusty environments, inspect the air filter restriction indicator frequently and clean the radiator and oil cooler fins to prevent overheating of the S4D95L-1A-C engine. Drain the fuel water separator daily to prevent water contamination in the injection system. Check all belts and hoses for UV degradation and cracking in high-heat conditions. Maintain proper track tension to reduce undercarriage wear on abrasive surfaces.

S4D95L-1A-C(S/N 48797-UP) common service parts

Part numberPart
600-311-9100Fuel Filter Ass'YCheck fitment →
6712-81-8620Plate? Caution,Additional Fuel FilterCheck fitment →
07281-00197Clamp,(With Pre-Fuel Filter)Check fitment →
600-311-8221Cartridge,Engine Fuel FilterCheck fitment →
6136-71-6120Cartridge,Engine Fuel FilterCheck fitment →

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

S4D95L-1A-C(S/N 48797-UP) fault codes & troubleshooting

CodeMeaningLikely causeWhat to do
CA115Engine speed sensor and backup speed sensor failureFaulty engine speed sensor, damaged wiring harness, or corroded connector at the sensor pin.Inspect the engine speed sensor and wiring harness for damage or corrosion; verify voltage at the pin connector; replace the sensor if faulty.
CA111Engine controller internal faultInternal failure of the Electronic Control Module (ECM) or engine controller.Inspect ECM power connections, fuses, and ground wires; replace or reprogram the ECM if the fault persists.
CA441Battery voltage is too lowWeak or discharged battery, faulty alternator, or loose/corroded battery cables.Check battery charge and condition; inspect alternator output and belt tension; tighten or replace battery cables.
CA442Battery voltage is too highFaulty voltage regulator, defective alternator, or poor battery condition.Test alternator output and voltage regulator function; replace the alternator or battery as necessary.
CA122Intake air pressure sensor feedback voltage is too highFaulty intake air pressure sensor, shorted wiring, or actual over-boost condition.Verify the intake air pressure sensor operation and wiring integrity; check for air intake restrictions or turbocharger issues.
CA123Intake air pressure sensor feedback voltage is too lowFaulty intake air pressure sensor, open circuit in wiring, or air leak in the intake system.Check for sensor short or open circuit; inspect the air intake system for leaks or blockages.
CA451Common rail pressure sensor feedback value is too highFaulty rail pressure sensor, actual overpressure condition, or wiring issue.Diagnose the fuel rail pressure sensor and associated wiring; check for actual overpressure in the fuel system.
CA559Common rail pressure is too lowFuel supply issue, faulty pressure sensor, or leaking fuel lines/injectors.Evaluate the fuel supply pump and regulator (IMV/PCV); inspect fuel lines and injectors for leaks.
AA10NXAir filter cloggingDirty or blocked air cleaner element.Replace the air filter element.
B@BCNSEngine coolant overheatingLow coolant level, faulty thermostat, clogged radiator, or failing water pump.Check radiator fins, fan belt, and coolant level; inspect for leaks or blockages in the cooling system.

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

S4D95L-1A-C(S/N 48797-UP) attachments & work tools

Excavator Buckets

The S4D95L-1A-C engine powers the PC100-5 and PC120-5 excavator series, which utilize standard digging buckets and grading buckets. Typical capacities for this class range from 0.3 to 0.6 cubic meters (0.4 to 0.8 cubic yards), varying by configuration/series.

Hydraulic Breakers

Compatible with the PC100-5 and PC120-5 frames, hydraulic breakers are a primary work tool for this engine class. Mounting requires a specific adapter plate and high-flow hydraulic lines to match the machine's auxiliary circuit.

Coupler Systems

Quick couplers are used for rapid tool changes on the PC100-5 and PC120-5 excavators. The mounting interface is specific to the boom and stick geometry of the 95 series, requiring verification of the exact stick length for proper fitment.

Hydraulic Piping Kits

Work tools requiring auxiliary hydraulics, such as breakers or grapples, require specific piping kits. These kits route high-pressure lines from the main control valve to the quick coupler or tool ports, with specifications varying by configuration/series.

Factory Guarding Options

Factory configurations for the PC100-5 and PC120-5 include optional undercarriage guards and cab guards to protect against falling material. These options are integrated into the machine's structural design and are not universal across all serial ranges.

All S4D95L-1A-C(S/N 48797-UP) assemblies by section

Every catalogued assembly group for the Komatsu S4D95L-1A-C(S/N 48797-UP). Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.

Cooling System
Komatsu : S4d95l-1a-C(S/N 48797-Up) : Cooling System : Corrosion Resistor (Except Japan)(#59654-)
07***12Gasket,(Without Air Compressor Type) (K1)4
09***02Plate? Instruction,(Indonesian-English)1
09***01Plate? Instruction,(English) (Except Japan)1
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Komatsu : S4d95l-1a-C(S/N 48797-Up) : Cooling System : Water Pump And Cooling Fan
01***16Screw5
01***20Screw2
01***30Bolt,(Water Separator Spec.)6
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Cylinder Block
Komatsu : S4d95l-1a-C(S/N 48797-Up) : Cylinder Block : Camshaft And Tappet
01***20Screw2
04***16Fitting Wedge1
62***31Thrust Washer1
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Komatsu : S4d95l-1a-C(S/N 48797-Up) : Cylinder Block : Crankshaft
01***35Screw1
62***00Main Metal Ass'Y5
62***00Thrust Metal Ass'Y1
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Komatsu : S4d95l-1a-C(S/N 48797-Up) : Cylinder Block : Cylinder Block
01***20Bolt,(For Japan Pc200)2
01***08Nut,See Fig. K4010-04a01
04***20Pin,Dowel (Welded)2
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Komatsu : S4d95l-1a-C(S/N 48797-Up) : Cylinder Block : Flywheel And Flywheel Housing (Except Japan)
01***30Bolt6
01***30Bolt - Lower Oil Cooler Outlet Tubemounting11
07***16Gasket,(For Pc750-6) (See Fig.A2110)1
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Komatsu : S4d95l-1a-C(S/N 48797-Up) : Cylinder Block : Front Cover And Gear
01***70Bolt,(For 75a Alternator)1
01***16Bolt2
01***16Screw2
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Komatsu : S4d95l-1a-C(S/N 48797-Up) : Cylinder Block : Oil Pan (Except Japan)(#48797-67198)
01***12Bolt,(Without R.P.C.U.)3
01***14Bolt,(W/Joy Stick Str.)(W/O Heater)24
01***14Bolt24
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Komatsu : S4d95l-1a-C(S/N 48797-Up) : Cylinder Block : Oil Pan (Except Japan)(#67199-)
01***12Bolt,(Without R.P.C.U.)3
01***14Bolt,(W/Joy Stick Str.)(W/O Heater)24
01***08Washer,(For 1 Attachment And Pat)3
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Komatsu : S4d95l-1a-C(S/N 48797-Up) : Cylinder Block : Piston And Connecting Rod
04***12Ring, Snap8
62***10Bolt2
62***41Piston (S)0
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Cylinder Head
Komatsu : S4d95l-1a-C(S/N 48797-Up) : Cylinder Head : Air Cleaner (Single Element Type)
04***10Ring,See Fig. K4010-65a01
07***69Clamp2
09***61Plate? Instruction,(Japanese-English)1
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Komatsu : S4d95l-1a-C(S/N 48797-Up) : Cylinder Head : Air Intake Manifold And Connection
01***12Bolt,(With Speedometer)4
01***12Bolt3
01***70Bolt4
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Komatsu : S4d95l-1a-C(S/N 48797-Up) : Cylinder Head : Cylinder Head
01***20Bolt, Hose Clamps (Inlet And Return Line Hoses)4
01***32Washer,(Not Used With Emergency Str.)17
01***32Washer, (Without Emergency Steering)17
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Komatsu : S4d95l-1a-C(S/N 48797-Up) : Cylinder Head : Cylinder Head Cover
01***14Screw1
04***50Screw4
07***80Clamp, Drain Hose3
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Komatsu : S4d95l-1a-C(S/N 48797-Up) : Cylinder Head : Exhaust Manifold And Turbocharger
01***25Grub Screw4
01***90Bolt,(For Large Fan)8
07***08Plug,(For W/O. Corrosion Resistor)1
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Komatsu : S4d95l-1a-C(S/N 48797-Up) : Cylinder Head : Muffler And Connection
01***50Bolt,(With Service Valve R.H.)1
01***20Bolt, Hose Clamps (Inlet And Return Line Hoses)2
01***25Bolt, Mount Engine Oil Drain To Fuel Tank5
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Komatsu : S4d95l-1a-C(S/N 48797-Up) : Cylinder Head : Rocker Arm
01***65Bolt,(For Alternator Bracket Mount)5
61***30Circlip2
62***00Shaft Ass'Y1
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Komatsu : S4d95l-1a-C(S/N 48797-Up) : Cylinder Head : Turbocharger (Except Japan)
62***10Turbocharger Ass'Y1
GA***16Bolt6
GA***31Housing,Compressor1
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Electrical System
Komatsu : S4d95l-1a-C(S/N 48797-Up) : Electrical System : Alternator (25a)
60***20Alternator A. (25a),(With Non Hardening Pulley)1
KD***57Bearing,Ball? Front1
KD***11Rear Bracket Ass'Y1
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Komatsu : S4d95l-1a-C(S/N 48797-Up) : Electrical System : Alternator And Mounting (25a) (With Cover Type) (Except Japan)(#59654-)
01***40Bolt,(Cold Weather Spec.)1
01***25Bolt,(With Corrosion Resistor)3
01***60Screw1
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Komatsu : S4d95l-1a-C(S/N 48797-Up) : Electrical System : Alternator And Mounting (25a) (Without Cover Type)
01***35Bolt,(Cold Weather Spec.)1
01***25Bolt,(With Corrosion Resistor)3
01***60Screw1
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Komatsu : S4d95l-1a-C(S/N 48797-Up) : Electrical System : Starting Motor (5.5kw)
60***20Starting Motor Ass'Y,(5.5kw)1
KD***30Bracket,Center1
KD***40Washer Ass'Y,(Not Shown)1
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Komatsu : S4d95l-1a-C(S/N 48797-Up) : Electrical System : Starting Motor And Mounting (5.5kw)
01***16Bolt,(With Alternator Cover Type)1
01***25Bolt,(With Corrosion Resistor)1
01***30Bolt2
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Engine Kit
Komatsu : S4d95l-1a-C(S/N 48797-Up) : Engine Kit : Gasket Kit
01***12Washer,Lock (Noise Suppression Spec.) (K2)1
07***18O-Ring,(See Fig.1601-29?1602-17)1
07***20O-Ring,Relief Valve1
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Fuel System
Komatsu : S4d95l-1a-C(S/N 48797-Up) : Fuel System : Additional Fuel Filter (Except Japan)(#59654-)
07***12Gasket,Mechanical Pump Piping2
60***00Fuel Filter Ass'Y1
60***20Cartridge,Pref1
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Komatsu : S4d95l-1a-C(S/N 48797-Up) : Fuel System : Fuel Filter And Piping
01***30Screw2
01***35Bolt1
01***80Bolt2
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Komatsu : S4d95l-1a-C(S/N 48797-Up) : Fuel System : Fuel Injection Pump (Feed Pump) (Except Japan)
DK***20Bolt, Joint1
DK***60Feed Pump Ass'Y1
DK***00Valve,Check2
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Komatsu : S4d95l-1a-C(S/N 48797-Up) : Fuel System : Fuel Injection Pump (Governor) (1/2) (Except Japan)
DK***00Shim? 2.00mm,(High Altitude Spec.)0
DK***00Adapter1
DK***20Limiter1
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Komatsu : S4d95l-1a-C(S/N 48797-Up) : Fuel System : Fuel Injection Pump (Governor) (2/2) (Except Japan)
DK***40Gasket,Air Compressor2
DK***00Nut,Cap1
DK***20Cover1
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Komatsu : S4d95l-1a-C(S/N 48797-Up) : Fuel System : Fuel Injection Pump (Pump) (1/2) (Except Japan)
62***70Injection Pump Ass'Y1
62***71Injection Pump Ass'Y1
DK***30Bearing0
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Komatsu : S4d95l-1a-C(S/N 48797-Up) : Fuel System : Fuel Injection Pump (Pump) (2/2) (Except Japan)
DK***40Shim? 0.50mm, Shim, 0.50mm; Was Dk029311-00400
DK***90Shim? 0.25mm, Shim, 0.25mm; Was Dk029311-05900
DK***00Sleeve,Control4
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Komatsu : S4d95l-1a-C(S/N 48797-Up) : Fuel System : Fuel Injection Pump And Piping (Except Japan)
01***35Stud4
01***12Bolt2
01***25Screw2
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Komatsu : S4d95l-1a-C(S/N 48797-Up) : Fuel System : Fuel Nozzle And Spill Pipe
01***35Bolt, Mount Bracket To Floor4
07***80Clip7
07***00Clip7
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Komatsu : S4d95l-1a-C(S/N 48797-Up) : Fuel System : Water Separator (Except Japan)(#59654-)
07***12Gasket,Mechanical Pump Piping1
60***31Separator Assembly, Water1
60***60Plug,Drain (4d105-5h? 4d105-5t)1
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Lubricating Oil System
Komatsu : S4d95l-1a-C(S/N 48797-Up) : Lubricating Oil System : Lubricating Oil Cooler
01***25Bolt,(With Corrosion Resistor)4
01***30Bolt,(Water Separator Spec.)7
01***50Bolt,(With Corrosion Resistor)1
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Komatsu : S4d95l-1a-C(S/N 48797-Up) : Lubricating Oil System : Lubricating Oil Filter
60***41Cartridge,Engine? Oil Filter1
60***20Plate? Caution,(Italian-English)1
60***70Plate? Caution,Oil Filter And Bypass Filter1
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Komatsu : S4d95l-1a-C(S/N 48797-Up) : Lubricating Oil System : Lubricating Oil Pump And Suction Pipe
01***12Bolt,(See Fig.0501)1
01***16Screw6
01***25Bolt,(With Corrosion Resistor)1
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Komatsu : S4d95l-1a-C(S/N 48797-Up) : Lubricating Oil System : Turbocharger Lubricating Oil Piping
01***16Screw5
01***20Screw4
01***30Bolt,(Water Separator Spec.)2
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S4D95L-1A-C(S/N 48797-UP) serial number reference

The engine serial number plate is stamped directly on the engine block, typically on the left side near the injection pump. The prefix is the alphanumeric engine model code (e.g., S4D95L-1A-C) stamped on this plate, not a 3-character PIN prefix; the 17-character ISO PIN is located on the separate EPA/EU emissions plate near the engine bay or cab pillar. For the S4D95L-1A-C engine (S/N 48797-UP), the engine model code is the critical identifier for parts ordering, as the chassis serial number (e.g., PC100-5 #28001-UP) determines the machine configuration while the engine code determines the powertrain components.

PrefixIdentifies
S4D95L-1A-CEngine Model

Frequently asked questions

What engine does the Komatsu PC100-5 and PC120-5 use?

The Komatsu PC100-5 and PC120-5 excavators use the S4D95L-1A-C engine, which is part of the 95 Series diesel engine family.

What is the operating weight of the Komatsu PC100-5 and PC120-5?

The operating weight varies by configuration and attachment package, but these mid-size excavators generally fall within the 20,000 to 60,000 lb class.

What replaced the Komatsu PC100-5 and PC120-5?

The PC100-5 and PC120-5 were succeeded by the PC100-6 and PC120-6 series excavators, which feature updated engines and hydraulic systems.

What S4D95L-1A-C(S/N 48797-UP) owners discuss

What is the cylinder head gasket kit cost for a Komatsu PC75UU-2 with a 4D95L-1 engine above serial the OEM part reference?
Over 1,000 (currency unspecified in source). Have your dealer verify pricing for your specific serial range, as costs vary by configuration/series and market availability. The source notes a new engine estimate of 15,000 and a rebuild estimate of 21,000 for this machine class. Have your dealer verify.
Does the Komatsu 4D95L-1 engine use wet or dry cylinder liners?
The 4D95 series engine does not have liners; it is a solid block design. Repair involves oversize pistons (up to.020 over) or machining the block to accept sleeves if necessary.
What are common signs of hydraulic system weakness in Komatsu excavators, and how do they differ from engine issues?
If all hydraulic functions (boom, arm, bucket, swing, travel) are slow simultaneously, check hydraulic oil level, correct oil specification, hydraulic filters, engine RPM under load, and oil temperature. If only one function is slow, investigate the specific cylinder, control valve, or hose. Engine power loss under load often correlates with hydraulic load; if engine RPM drops heavily when hydraulics are used, the hydraulic system may be dragging the engine down or the engine cannot produce expected power. Have your dealer verify hydraulic pressures.
What are typical undercarriage and wear patterns for Komatsu excavators, and how do they affect resale value?
Komatsu lines are noted for smooth operation and fuel efficiency. However, some owners report that the line is designed to wear out complete machines simultaneously; if a pump fails, the engine may follow. This contributes to lower resale value.
What electrical or sensor issues are commonly reported for Komatsu excavators?
Komatsu excavators rely heavily on electronic control systems. Common issues include intermittent starting, dashboard failure, and random shutdowns triggered by faulty sensors or unstable power supplies. Multiple fault codes may indicate battery, ground, or connector issues. Have your dealer verify electrical system integrity and sensor readings.
What should be checked when buying a used Komatsu excavator with a 4D95L-1 engine?
Verify the exact engine serial number to determine parts availability and cost (higher serial numbers may have different/expensive parts). Check for exhaust in the cooling system (a known issue with 4D95 series). Inspect the engine for bent rods or blown head gaskets. Confirm the engine type is Komatsu 4D95 and not a Yanmar (which was used in some similar machines). Check hydraulic oil condition and temperature behavior (weakness when hot indicates internal leakage).
What is the relationship between the Cummins 3.3 and Komatsu 4D95L engines regarding parts?
The Cummins 3.3 and Komatsu 4D95L are considered the same engine family. Early Cummins parts numbers (e.g., cylinder head gasket C6204111840) correspond to Komatsu parts numbers (6204111840). Most parts can be generic, but finding the exact 4D95 variant matching the Cummins B3.3 is critical for correct overhaul kits. Have your dealer verify the exact engine variant and compatible parts.

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

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