Service parts for the D125
Grouped by system, with how many of each the parts manual calls for.
Fuel system
1 requiredPrices captured from merchant listings; some links are affiliate links. Confirm against your serial number before ordering.
Specifications
| Fuel | diesel |
|---|---|
| Frequency | 60.0 Hz |
| Standby power | 125 kW |
| Standby kVA | 156 |
| Prime power | 114 kW |
| Emissions | EPA Tier 3 |
| Controller | EMCP 3.1, EMCP 4.2 |
| Oil capacity | 16.5 L |
| Alternator | LC3014F (4-pole, Class Class H insulation) |
| Voltage options | 208 V |
| Phase | 3 |
| Rated current | 347 A |
| Power factor | 1 |
| Circuit breaker | 100 A |
| Battery group | Not specified |
| Battery voltage | 12 V |
| Battery quantity | 1 |
| Coolant capacity | 21.0 L |
| Max ambient | 50 °C |
| Dimensions (L×W×H) | 3037×1110×483 mm |
| Dry weight | 1347 kg |
| Sound level | 97.0 dBA @ 1 m |
| Tank runtime | Not specified hr |
Engine
| Oil capacity | 16.5 L |
|---|---|
| Coolant capacity | 21.0 L |
| Displacement | 6.6 L |
| Aspiration | NA |
| Rated speed | 1800 rpm |
Filters for the Caterpillar C6.6
6Engine-mounted filters the filter manufacturers list for this engine family. These come from the engine, not from this generator set’s own parts list, so confirm against your serial number before ordering.
| System | Filter | Description | Cross-references | |
|---|---|---|---|---|
| Oil filter | P550920 | Lube Filter, Spin-On Full Flow | CATERPILLAR 2698325, CATERPILLAR 4621171, NAPA 7325, BALDWIN B7378 | KuduParts $45.00 FridayParts $46.80 |
| Oil filter | P551808 | Lube Filter, Spin-On Full Flow | CATERPILLAR 1R1808, CATERPILLAR 1R808, NAPA 7792, BALDWIN B7299 | KuduParts $80.00 |
Listed for this engine in only one kind of machine, so they may depend on how the engine was installed:
| System | Filter | Description | Cross-references | |
|---|---|---|---|---|
| Fuel filter | P551062 | Fuel Filter, Cartridge | BALDWIN PF7939, MERCEDES-BENZ 0000900751, MERCEDES-BENZ 0000902051, MERCEDES-BENZ 0000924105 | buy |
| Fuel filter | P550625 | Fuel Filter, Spin-On Secondary | CATERPILLAR 1165436, CATERPILLAR 1R0762, NAPA 3640, BALDWIN BF7753 | buy |
| Fuel / water separator | P552040 | Fuel Filter, Water Separator Cartridge | CATERPILLAR 3I1253, NAPA 3798, CLAAS 0000687120, CLAAS 0025981840 | buy |
| Fuel / water separator | P551855 | Fuel Filter, Water Separator Spin-On | BALDWIN BF1390-O, CLAAS 0007962130, MANITOWOC 03322877, FREIGHTLINER 0343845000 | FridayParts $39.06 |
Maintenance & consumables
for the Caterpillar C6.6| Item | Spec | Capacity | Part # | Interval | |
|---|---|---|---|---|---|
| Air filter | Air filter with monitoring system | — | |||
| Fuel filter | — | ||||
| Fuel filter | Cat high efficiency fuel filters with Stay-Clean Valve, primary and secondary filters in engine compartment | 1466695 | Amazon eBay $35.86 FridayParts $33.99 | ||
| Oil filter | Caterpillar air filter for engine compartment | — | 512 hr | ||
| Battery | ×2 | — | |||
| Belt | — | ||||
| Coolant | Extended Life Coolant or conventional heavy-duty coolant | — | |||
| Coolant filter | 50% coolant antifreeze with corrosion inhibitor | — | |||
| Oil | — | ||||
| Spark plug | — |
Compatible filters for the Caterpillar C6.6 — cross-referenced via Donaldson. Options to verify against your serial number, not confirmed for this exact unit.
Service intervals
1| Item | Action | Hours | Months | Notes |
|---|---|---|---|---|
| Engine oil filter | Replace | 512 hr | Last changed 6/10/24, 512HRS |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
Service specifications
1| Type | Item | Value | Unit | Condition |
|---|---|---|---|---|
| Voltage | DC Voltage | 13.8 | V | load bank test, all stages |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
Recommended fluids
| Fluid | Grade | Standard | Ambient | Capacity | Notes |
|---|---|---|---|---|---|
| Fuel | EPA 2D 89.330-96 | Density 0.845 – 0.850 kg/L (7.052 – 7.094 lbs/U.S. gal.) @ 15°C (59°F); fuel inlet temperature 40°C (104°F); fuel rates based on this specification |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
Procedures
1Load Bank Test diagnostic
Tools: Load bank
- Warm up
- Start and record no-load readings
- Apply load and record readings at 15 min
- Record readings at 30 min
- Record readings at 45 min
- Record readings at 1 hour
- Cool down and record readings
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
Common questions
How many kW is the Caterpillar D125?
The Caterpillar D125 is rated 125 kW standby (156.3 kVA).
What engine does the Caterpillar D125 use?
The Caterpillar D125 is powered by the Caterpillar C6.6 engine.
Is the Caterpillar D125 diesel or gas?
The Caterpillar D125 runs on diesel.
What is the oil capacity of the Caterpillar D125?
The Caterpillar C6.6 engine in the Caterpillar D125 has an oil capacity of 16.5 liters.
What is the cooling system capacity of the Caterpillar D125?
The Caterpillar D125 cooling system holds 21 liters (5.5 US gallons) for the radiator system including the engine, per the manufacturer specification sheet.
What is the prime power rating of the Caterpillar D125?
The Caterpillar D125 is rated 114 kW prime (142 kVA), against 125 kW standby.
What is the sound level of the Caterpillar D125?
The Caterpillar D125 is rated at 97.0 dBA at 1 m, per the manufacturer specification sheet.
What is the dry weight of the Caterpillar D125?
The Caterpillar D125 has a dry weight of 1347 kg (2969 lb).
What voltages is the Caterpillar D125 available in?
The Caterpillar D125 is offered in 208 V, 3-phase.
What battery does the Caterpillar D125 use?
The Caterpillar D125 uses 1 battery, 12 V each, group Not specified, per the manufacturer specification sheet.
What alternator comes on the Caterpillar D125?
The Caterpillar D125 uses a LC3014F alternator. It has 4 poles. Insulation class Class H.
What oil filter fits the Caterpillar D125?
The Caterpillar D125 uses oil filter part numbers CATERPILLAR 4621171, CATERPILLAR IR1807.
What fuel filter does the Caterpillar D125 use?
The Caterpillar D125 uses fuel filter part number 1466695.
What air filter does the Caterpillar D125 use?
The Caterpillar D125 uses air filter part numbers CATERPILLAR 2525001, CATERPILLAR 2525002.
Repair guides
1Step-by-step procedures compiled from the Caterpillar service manual for this model.
Parts
16| Part # | Description | Qty | System | |
|---|---|---|---|---|
| JPR-HDS170 | PUMP ASSY | 1 | Pump | Amazon eBay |
| S200-0369 | Maintenance-free battery, 1000 CCA (2) | 1 | Battery | Amazon eBay |
| S200-0578 | Directional signals, front & rear | 1 | Light | Amazon eBay |
| S200-0632 | Starting and charging system, 24V | 1 | Battery | Amazon eBay |
| S200-0758 | Halogen work lights, front & rear | 1 | Light | Amazon eBay |
| S200-0863 | Keyless ignition stop/start switch | 1 | Ignition | Amazon eBay |
| S200-0957 | Roading lights | 1 | Light | Amazon eBay |
| S200-1038 | Starting aid, thermal | 1 | Ignition | Amazon eBay |
| S200-1156 | Keyless battery disconnect switch | 1 | Battery | Amazon eBay |
| 389024500-C | Coolant heater, 1500W, 120V | 1 | Service part / kit | eBay |
| AEHQ5826-01 | Replaces AEHQ5826-01 | Service part / kit | Amazon eBay | |
| INT9-101F | Replaces any core plug | Service part / kit | Amazon eBay | |
| INT9-102F | Replaces any core plug | Service part / kit | Amazon eBay | |
| NRG22-10-RC | Battery charger, 120/208-240V, 6/3A | 1 | Service part / kit | eBay |
| PA50 | Winch Model PA50 | 1 | Service part / kit | Amazon eBay |
| TPL-489-C | OPERATING & MAINTENANCE OF D175 | Service part / kit | Amazon eBay |
Service, wear & replacement parts referenced for this model and its engine — confirm the exact part for your serial number. See the full parts catalog to search and cross-reference.
Fuel consumption
| Rating | Load | L/h | gal/h |
|---|---|---|---|
| Prime | 50% | 19.9 | 5.3 |
| Prime | 75% | 27.4 | 7.2 |
| Prime | 100% | 34.6 | 9.1 |
| Standby | 50% | 21.4 | 5.7 |
| Standby | 75% | 29.6 | 7.8 |
| Standby | 100% | 37.3 | 9.9 |
Available documents
This page was generated from the 4 manufacturer documents above by automated extraction; every figure shown is copied from one of them. How the data is compiled.