Service parts for the 3412C
Grouped by system, with how many of each the parts manual calls for.
Air intake
1 requiredOil system
1 requiredBelts
1 requiredCooling system
1 requiredPrices captured from merchant listings; some links are affiliate links. Confirm against your serial number before ordering.
Specifications
| Fuel | diesel |
|---|---|
| Frequency | 50.0 Hz |
| Standby power | 640 kW |
| Standby kVA | 750 |
| Prime power | 400 kW |
| Emissions | Low BSFC |
| Oil capacity | 139.1 L |
| Coolant capacity | 67.1 L |
| Dimensions (L×W×H) | 2119×1444×1621 mm |
| Dry weight | 2458 kg |
Engine
| Oil capacity | 139.0 L |
|---|---|
| Coolant capacity | 58.0 L |
| Displacement | 27.0 L |
| Aspiration | TA |
| Rated speed | 1800 rpm |
Maintenance & consumables
for the Caterpillar 3412C| Item | Spec | Capacity | Part # | Interval | |
|---|---|---|---|---|---|
| Air filter | Air filter outer | 4N0015 | eBay $109.99 KuduParts $114.00 | ||
| Fuel filter | Filter fuel | 1R0749 | Amazon $90.99 Amazon $19.99 eBay $135.88 eBay $135.88 KuduParts $17.00 | ||
| Fuel filter | Primary Filter (Water Separator) | 3089679 | 250 hr | Amazon eBay $16.89 PartsGeek $25.97 FridayParts $58.99 | |
| Oil filter | Filter oil | 1R1808 | Amazon $70.99 eBay $141.00 eBay $59.99 KuduParts $80.00 | ||
| Battery | Maintain electrolyte level to FULL mark; use distilled water | — | 250 hr | ||
| Belt | V-belt | 118-2018 | eBay $74.43 FridayParts $21.56 | ||
| Coolant | DEAC or ELC | 58.0 | — | 6000 hr | |
| Coolant filter | Cat ELC Extender added once | 9Y1022 | 6000 hr | eBay $20.00 | |
| Oil | 139.0 | — | 500 hr | ||
| Spark plug | Replace spark plugs every 1,000 hours or as needed. | — | 1000 hr |
Service intervals
40| Item | Action | Hours | Months | Notes |
|---|---|---|---|---|
| Sea Water Strainer | Clean | 50 hr | When required and every 3800 L (1000 US gal) of fuel or 50 service hours | |
| Zinc Rods | Inspect | 50 hr | When required and every 3800 L (1000 US gal) of fuel or 50 service hours; replace when deteriorated | |
| Alternator Belt | Inspect | 250 hr | 12 mo | Inspect/adjust/replace; every 12 750 L (3375 US gal) of fuel or 250 h or yearly (8RG1-Up); every 19 000 L (5000 US gal) or 250 h or yearly (REA1-Up, 3JK1-Up, 7BL1-Up) |
| Alternator and Fan Belts | Replace | 250 hr | Inspect/Adjust/Replace - Every 19 000 L (5000 US gal) of Fuel or 250 Service Hours | |
| Battery Electrolyte Level | Check | 250 hr | 12 mo | Every 19 000 L (5000 US gal) of Fuel or 250 Service Hours |
| Cooling System Coolant Sample (Level 1) | Test | 250 hr | Obtain - Every 250 Service Hours | |
| Cooling System Supplemental Coolant Additive (SCA) | Test | 250 hr | 12 mo | Test/Add; 8RG1-Up: 12 750 L (3375 US gal) or 250 h or yearly; other S/N: 19 000 L (5000 US gal) or 250 h or yearly |
| Engine Air Cleaner Element | Clean | 250 hr | 12 mo | Clean/Replace; 8RG1-Up: 12 750 L (3375 US gal) or 250 h or yearly; other S/N: 19 000 L (5000 US gal) or 250 h or yearly |
| Engine Crankcase Breather | Clean | 250 hr | 12 mo | Every 19 000 L (5000 US gal) of Fuel or 250 Service Hours |
| Engine Oil Sample | Other | 250 hr | 12 mo | Obtain S·O·S oil sample; 8RG1-Up: 12 750 L (3375 US gal) or 250 h or yearly; other S/N: 19 000 L (5000 US gal) or 250 h or yearly |
| Engine Oil and Filter | Change | 250 hr | 12 mo | 8RG1-Up: 12 750 L (3375 US gal) or 250 h or yearly; other S/N: 19 000 L (5000 US gal) or 250 h or yearly |
| Engine Protective Devices | Check | 250 hr | Every 19 000 L (5000 US gal) of Fuel or 250 Service Hours | |
| Fuel System Primary Filter | Clean | 250 hr | 12 mo | Clean/Replace; 8RG1-Up: 12 750 L (3375 US gal) or 250 h or yearly; other S/N: 19 000 L (5000 US gal) or 250 h or yearly |
| Fuel System Secondary Filter | Replace | 250 hr | 12 mo | 8RG1-Up: 12 750 L (3375 US gal) or 250 h or yearly; other S/N: 19 000 L (5000 US gal) or 250 h or yearly |
| Fuel Tank Water and Sediment | Drain | 250 hr | 12 mo | 8RG1-Up: 12 750 L (3375 US gal) or 250 h or yearly; other S/N: 19 000 L (5000 US gal) or 250 h or yearly |
| Hoses and Clamps | Inspect | 250 hr | 12 mo | Inspect/Replace; 8RG1-Up: 12 750 L (3375 US gal) or 250 h or yearly; other S/N: 19 000 L (5000 US gal) or 250 h or yearly |
| Magnetic Pickups | Clean | 250 hr | First service — Clean/Inspect - First 19 000 L (5000 US gal) of Fuel or 250 Service Hours | |
| Aftercooler Core | Clean | 1000 hr | When required; also every 76 000 L (20 000 US gal) of fuel or 1000 service hours | |
| Heat Exchanger | Inspect | 1000 hr | When required; also every 76 000 L (20 000 US gal) of fuel or 1000 service hours | |
| Engine Speed/Timing Sensors | Check | 1500 hr | Check/Clean/Calibrate; 76 500 L (20 250 US gal) of fuel or 1500 h (8RG1-Up); 114 000 L (30 000 US gal) or 1500 h (REA1-Up, 3JK1-Up, 7BL1-Up) | |
| Engine Valve Lash | Adjust | 1500 hr | First service — Inspect/Adjust; 76 500 L (20 250 US gal) of fuel or 1500 h (8RG1-Up); 114 000 L (30 000 US gal) or 1500 h (other S/N) | |
| Engine Valve Rotators | Inspect | 1500 hr | 76 500 L (20 250 US gal) of fuel or 1500 h (8RG1-Up); 114 000 L (30 000 US gal) or 1500 h (other S/N) | |
| Cooling System Coolant Sample (Level 2) | Test | 2000 hr | 12 mo | First service — Obtain - Every 2000 Service Hours or 1 Year |
| Engine | Clean | 2000 hr | 6 mo | Every 2000 Service Hours or 6 Months |
| Fuel System | Other | 2000 hr | 6 mo | Prime - Every 2000 Service Hours or 6 Months |
| Generator | Other | 2000 hr | 6 mo | Dry - Every 2000 Service Hours or 6 Months |
| Generator Lead (Round Cable) | Check | 2000 hr | Every 2000 Service Hours | |
| Generator Set | Test | 2000 hr | 6 mo | Every 2000 Service Hours or 6 Months |
| Rotating Rectifier | Test | 2000 hr | 6 mo | Every 2000 Service Hours or 6 Months |
| Severe Service Application | Check | 2000 hr | 6 mo | Every 2000 Service Hours or 6 Months |
| Alternator | Inspect | 3000 hr | 153 500 L (40 500 US gal) of fuel or 3000 h (8RG1-Up); 228 000 L (60 000 US gal) or 3000 h (REA1-Up, 3JK1-Up, 7BL1-Up) | |
| Auxiliary Water Pump | Inspect | 3000 hr | 153 500 L (40 500 US gal) of fuel or 3000 h (8RG1-Up); 228 000 L (60 000 US gal) or 3000 h (other S/N) | |
| Cooling System Coolant (DEAC) | Change | 3000 hr | 153 500 L (40 500 US gal) of fuel or 3000 h (8RG1-Up); 228 000 L (60 000 US gal) or 3000 h (other S/N) | |
| Cooling System Water Temperature Regulator | Replace | 3000 hr | 153 500 L (40 500 US gal) of fuel or 3000 h (8RG1-Up); 228 000 L (60 000 US gal) or 3000 h (other S/N) | |
| Crankshaft Vibration Damper | Inspect | 3000 hr | 153 500 L (40 500 US gal) of fuel or 3000 h (8RG1-Up); 228 000 L (60 000 US gal) or 3000 h (other S/N) | |
| Engine Mounts | Inspect | 3000 hr | 153 500 L (40 500 US gal) of fuel or 3000 h (8RG1-Up); 228 000 L (60 000 US gal) or 3000 h (other S/N) | |
| Fuel Injection Nozzles | Test | 3000 hr | Test/Exchange; 153 500 L (40 500 US gal) of fuel or 3000 h (8RG1-Up); 228 000 L (60 000 US gal) or 3000 h (other S/N) | |
| Starting Motor | Inspect | 3000 hr | 153 500 L (40 500 US gal) of fuel or 3000 h (8RG1-Up); 228 000 L (60 000 US gal) or 3000 h (other S/N) | |
| Turbocharger | Inspect | 3000 hr | 153 500 L (40 500 US gal) of fuel or 3000 h (8RG1-Up); 228 000 L (60 000 US gal) or 3000 h (other S/N) | |
| Cooling System Coolant Extender (ELC) | Other | 6000 hr | 36 mo | Add; every 6000 service hours or 3 years |
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
60| Type | Item | Value | Unit | Condition |
|---|---|---|---|---|
| Clearance | Bearing bracket step minimum | less than 0.0762 | mm | |
| Clearance | Coolant level below bottom of filler pipe (engines without recovery tank) | within 13 | mm | 0.5 inch |
| Clearance | Water pump leakage considered normal as engine cools | small amount | water pump seal is lubricated by coolant in the cooling system | |
| Other | Alternator belt deflection | 13 to 19 | mm | 110 N (25 lb) of force applied midway between the pulleys; 0.50 to 0.75 inch |
| Other | Belt tension deflection | 0.50 to 0.75 | inch | 110 N (25 lb) force midway between pulleys |
| Other | Belt tension deflection | 13 to 19 | mm | 110 N (25 lb) force midway between pulleys |
| Other | Caterpillar Fast Acting Cooling System Cleaner concentration | 0.5 | L per 15 L | 1 pint per 4 US gal of cooling system capacity |
| Other | Chlorine content limit for heat exchanger cleaning water | more than 300 | ppm | water containing more than 300 ppm of chlorine should not be used |
| Other | Coolant level below filler pipe bottom | 13 | mm | |
| Other | Cooling system fill rate | no faster than 19 | L per minute | 5 US gal per minute to avoid air locks |
| Other | Cooling system fill rate (maximum) | 19 | L per minute | to avoid air locks |
| Other | Engine valve rotator operation | should turn slightly when valves close | ||
| Other | Generator excitation PMG short circuit capability | 3 X In for 10 seconds | ||
| Other | High idle speed for droop governors | approximately 2% to 5% | above full load speed | governors equipped with droop |
| Other | Paper air cleaner element reuse limit | up to six | times | replace at least one time per year regardless of number of cleanings |
| Other | Plate type heat exchanger cleaner concentration | maximum 4 | percent by weight | cleaning solution temperature less than 60°C (140°F) |
| Other | Solvent contact time with heat exchanger gaskets | not more than half an hour | natural rubber, butyl rubber and EPDM gaskets swell in these solvents | |
| Other | Speed droop values commonly used | 3% and 0% | % | |
| Other | Supplemental Coolant Additive (SCA) concentration, coolant and SCA | do not exceed six | percent | |
| Other | Supplemental Coolant Additive (SCA) concentration, water and SCA | do not exceed eight | percent | |
| Other | Vibration damper inspection | dented, cracked, leaking, bent or discolored damper must be replaced | ||
| Other | Voltage droop for 0.8 power factor load | approximately 5 | % | loads with a power factor of 0.8 |
| Pressure | Auxiliary water pump differential pressure requiring component inspection | more than 103 | kPa | 15 psi |
| Pressure | Coolant system pressure test - use 9S-8140 Pressurizing Pump | 9S-8140 | ||
| Pressure | Engine oil pressure at low idle | 186 to 344 | kPa | low idle speed |
| Pressure | Fuel pressure (below which engine will not operate properly) | 160 | kPa | |
| Pressure | Maximum air pressure at nozzle for cleaning | less than 205 | kPa | 30 psi |
| Pressure | Maximum air pressure for cleaning | 205 | kPa | deadheaded nozzle with chip guarding |
| Pressure | Maximum air pressure for cleaning purposes | 205 | kPa (30 psi) | must be below |
| Pressure | Maximum pressure of filtered, dry air for cleaning paper air cleaner elements | 207 | kPa | 30 psi |
| Pressure | Maximum water pressure for cleaning | 275 | kPa | |
| Pressure | Maximum water pressure for cleaning purposes | 275 | kPa (40 psi) | must be below |
| Pressure | Maximum water pressure for rinsing air cleaner element | 275 | kPa | 40 psi; do not use a spray nozzle |
| Pressure | Minimum recommended oil pressure | 103 | kPa | 600 rpm |
| Pressure | Minimum recommended oil pressure | 15 | psi | 600 rpm |
| Pressure | Normal operating engine oil pressure | 275 to 600 | kPa | engine running at rated engine speed, SAE 10W30 oil, operating oil temperature 104 C (219.2 F), normal engine water temperature |
| Pressure | Primary filter/water separator change pressure | 50 to 70 | kPa | 15 to 20 inches Hg |
| Pressure | Typical engine oil pressure at rated rpm with SAE10W30 (turbocharged) | 275 to 606 | kPa | rated rpm |
| Pressure | Typical engine oil pressure at rated rpm with SAE10W30 (turbocharged) | 40 to 88 | psi | rated rpm |
| Resistance | Exciter Armature (Rotor) (L2) resistance | less than 0.1 | ohm | room temperature |
| Resistance | Exciter Field (Stator) (L1) resistance | 3.0 to 6.0 | ohms | room temperature |
| Resistance | Insulation resistance minimum (contaminated generator) | 1 | megohm | |
| Resistance | Main Armature (Stator) (L4) resistance | less than 0.1 | ohm | room temperature |
| Resistance | Main Field (Rotor) (L3) resistance | 0.75 to 2.0 | ohms | room temperature |
| Resistance | Pilot Exciter Armature (L5) resistance | less than 0.1 | ohm | room temperature |
| Resistance | Varistor (CR7) resistance | minimum 15000 | ohms | |
| Speed | Actual RPM of overspeed (1500 full load rpm) | 1770 | rpm | multiply full load RPM by 1.18 |
| Speed | Actual RPM of overspeed (1800 full load rpm) | 2124 | rpm | multiply full load RPM by 1.18 |
| Speed | Engine speed for purging air from engine block cavities during coolant fill | 1500 | rpm | run one minute at 1500 rpm; low idle to increase |
| Speed | Frequency vs RPM - four-pole generator | divide the RPM by 30 | Hz | |
| Speed | Frequency vs RPM - six pole generator | divide the RPM by 20 | Hz | |
| Speed | Generator set functional test minimum phase voltage | 85 | VAC | half rated speed |
| Speed | Low idle (50 Hz units) | 80 | percent of full load speed | |
| Speed | Low idle (50 Hz units) | approximately 80 | % of full load speed | 50 Hz units |
| Speed | Low idle (60 Hz units) | 66 | percent of full load speed | |
| Speed | Low idle (60 Hz units) | approximately 66 | % of full load speed | 60 Hz units |
| Speed | Magnetic pickup crank termination | 400 | rpm | starter pinion disengagement |
| Speed | Overspeed switch setpoint | 118 | percent of rated engine speed | |
| Speed | Test RPM for overspeed (1500 full load rpm) | 1328 | rpm | multiply full load RPM by 0.885 |
| Speed | Test RPM for overspeed (1800 full load rpm) | 1593 | rpm | multiply full load RPM by 0.885 |
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 |
|---|---|---|---|---|---|
| Coolant | Cat DEAC | Diesel; 3,000 Service Hours or Three Years; annual S·O·SSM Level 2 coolant sampling and analysis | |||
| Coolant | Cat DEAC (Diesel Engine Antifreeze/Coolant) | Conventional heavy-duty coolant/antifreeze; commercial long life coolants meeting Caterpillar EC-1 | Level 1 coolant sample every 250 hours; Level 2 yearly; DEAC change every 3000 service hours | ||
| Coolant | Cat DEAC Diesel Engine Antifreeze/Coolant | ASTM D4985 or ASTM D5345 | 58.0 L | Acceptable; 1:1 mixture of water and glycol; service life three years; does not require SCA at initial fill | |
| Coolant | Cat ELC | Diesel; 12,000 Service Hours or Six Years; add Cat ELC Extender at 6,000 service hours or one half of service life; annual S·O·SSM Level 2 coolant sampling and analysis | |||
| Coolant | Cat ELC (Extended Life Coolant) | Does not require frequent SCA additions; Level 1 sample optional, Level 2 yearly; ELC change every 12 000 service hours or 6 years | |||
| Coolant | Cat ELC Extended Life Coolant | Caterpillar EC-1 | 58.0 L | Preferred; 1:1 mixture of water and glycol; service life six years; add ELC Extender once | |
| Coolant | Cat ELC Extender | Add every 6000 service hours or 3 years according to requirements for cooling system capacity | |||
| Coolant | Cat NGEC | Natural Gas; 16,000 Service Hours or Three Years; use interval that occurs first | |||
| Coolant | Caterpillar SCA and Water | For stationary applications not requiring boiling/freezing protection; minimum six percent to maximum eight percent SCA concentration; service life two years | |||
| Engine oil | Cat NGEO | Natural Gas | |||
| Engine oil | SAE 10W30 | Referenced as the oil used when normal operating engine oil pressure is specified | |||
| Engine oil | Cat Arctic DEO SYN SAE 0W-30 | -40°C to 30°C | Engine Crankcase; Industrial Engines | ||
| Engine oil | SAE 0W-20 | Cat DEO Multigrade API CH-4/API CG-4 | -40°C to 10°C | ||
| Engine oil | SAE 0W-30 | Cat DEO Multigrade API CH-4/API CG-4 | -40°C to 30°C | ||
| Engine oil | SAE 0W-40 | Cat DEO Multigrade API CH-4/API CG-4 | -40°C to 40°C | ||
| Engine oil | Cat DEO SYN SAE 5W-40 | -30°C to 50°C | Engine Crankcase; Industrial Engines | ||
| Engine oil | SAE 5W-30 | Cat DEO Multigrade API CH-4/API CG-4 | -30°C to 30°C | ||
| Engine oil | SAE 5W-40 | Cat DEO Multigrade API CH-4/API CG-4 | -30°C to 50°C | ||
| Engine oil | Cat DEO SAE 10W-30 | -18°C to 40°C | Engine Crankcase; Industrial Engines | ||
| Engine oil | SAE 10W-30 | Cat DEO Multigrade API CH-4/API CG-4 | -18°C to 40°C | ||
| Engine oil | Cat DEO SAE 15W-40 | -9°C to 50°C | Engine Crankcase; Industrial Engines | ||
| Engine oil | SAE 15W-40 | Cat DEO Multigrade API CH-4/API CG-4 | -9°C to 50°C | ||
| Fuel | LCV = 42700 kJ/kg | MaK technical data; without engine-driven pumps, tolerance 5% | |||
| Fuel | 35° API gravity at 60°F (16°C) | LHV 18,390 Btu/lb (42 780 kJ/kg) | Fuel at 85°F (29°C) weighing 7.001 lbs/U.S. gal (838.9 g/liter) | ||
| Fuel | No. 1-D or No. 2-D | ASTM D975 | Use No. 1 diesel fuel or a blend of No. 1 and No. 2 for cold-weather operation; No. 2 is most commonly used | ||
| Grease | Cat Generator Set Grease | Part Number 108-8611 | |||
| Grease | High Speed Ball Bearing Grease | Fan drive bearing grease fitting | |||
| Grease | Multipurpose Grease | 1P-0808 | Fuel control linkage lubrication | ||
| Grease | NLGI No. 1.5 Grade | Caterpillar 108-8611 Grease Cartridge for spherical roller bearings; contains Clay thickener; no molybdenum disulfide; viscosity 32 cSt at 40 C, 5 cSt at 100 C | |||
| Grease | NLGI No. 2 Grade | -29°C to 177°C | Caterpillar 2S-3230 Bearing Lubricant for ball bearings; contains Polyurea thickener; for extremely low temperatures use NLGI No. 1 Grade or NLGI No. 0 Grade |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
Procedures
12Alternator Belt - Inspect/Adjust/Replace adjustment
⚠ Replace belts for multiple groove pulleys in matched sets.
Tools: Belt tension gauge (110 N / 25 lb force)
- Remove the belt guard.
- Loosen mounting bolt (2) and adjusting nuts (1).
- Turn adjusting nuts to increase or decrease belt tension.
- Check deflection is 13 to 19 mm with 110 N applied midway.
- Tighten the adjusting nuts; tighten the mounting bolt.
- Reinstall the belt guard.
- Check adjustment again after 30 minutes at rated rpm if new belts.
Engine Valve Lash - Inspect/Adjust adjustment
⚠ Hot engine components can cause burns.
⚠ Only qualified service personnel should perform this maintenance.
- Ensure the engine cannot be started; do not use the starting motor to turn the flywheel.
- Ensure the engine is stopped and allow valves to cool.
- Refer to the Systems Operation/Testing and Adjusting Manual for the complete procedure.
- Set inlet valve lash to 0.38 mm (0.0150 inch).
- Set exhaust valve lash to 0.76 mm (0.030 inch).
- Perform initial adjustment at the first scheduled oil change.
VR3 Regulator Adjustment Procedure adjustment
⚠ The VR3 regulator is protected by a fuse(s) and a solid-state overcurrent protection. If a fuse becomes open, contact a Caterpillar dealer.
- Remove the access panel of the generator.
- Loosen the locknut on the voltage droop potentiometer (1).
- Remove the protective screw from the voltage level potentiometer (2) and from the voltage gain potentiometer (3).
- Turn the voltage droop potentiometer (1) counterclockwise to zero droop. Tighten the locknut.
- Turn the voltage gain potentiometer (3) counterclockwise to zero, then to about 1/4 of full range of clockwise travel.
- Perform required maintenance on the engine before you start the engine.
- Start the engine and allow the engine to warm up.
- Increase engine speed to full governed rated speed (high idle).
- Set the no-load voltage with the voltage level potentiometer (2) or the voltage adjust rheostat.
- Close the load circuit breaker and apply full load gradually. Adjust governor control to nameplate frequency or rated speed.
- If the voltmeter reading increases above no-load voltage, turn the voltage gain potentiometer counterclockwise. If it decreases, turn it clockwise.
- Remove the load. If necessary, adjust the voltage level potentiometer (2) to obtain desired voltage.
- Apply the load. Repeat Steps 10 through 12 until the voltage at no load equals the voltage at full load.
- Tighten the locknuts. Install the protective screws and the access panel of the generator.
Generator Set Functional Test diagnostic
⚠ Do not operate the generator set at a speed higher than one-half of the rated speed.
Tools: 6V-7070 Digital Multimeter, 12 VDC battery, Potential Transformer
- Stop the generator. Connect the potential transformer's high voltage winding to generator terminals T1 and T2. Connect the voltmeter to the low voltage winding.
- Disconnect wires F1+ and F2- from the voltage regulator. Disconnect the generator from the load.
- Connect a 12 VDC automotive battery to wires F1+ and F2-.
- Operate the generator set at half the rated speed.
- Measure the AC voltage across the low voltage terminals corresponding to T1-T2, T2-T3, and T3-T1. Record the voltages.
- Monitor the voltage between any two locations, then decrease the generator set speed by 10 percent and increase it by 10 percent.
- The measured voltages should be nearly equal and should measure a minimum of 85 VAC.
- When speed is decreased by 10 percent the voltages should decrease by 10 percent; when increased by 10 percent the voltages should increase by 10 percent.
Rotating Rectifier - Test diagnostic
Tools: 6V-7070 Digital Multimeter, 146-4080 Digital Multimeter (RS-232)
- Touch the red ohmmeter lead to the rectifier terminal marked '+'.
- Touch the black ohmmeter lead to terminals AC1, AC2, and AC3; the meter should indicate an open circuit or high resistance.
- Touch the black ohmmeter lead to the rectifier terminal marked '+'.
- Touch the red ohmmeter lead to terminals AC1, AC2, and AC3; the meter should indicate a good diode or low resistance.
- Touch the black ohmmeter lead to the rectifier terminal marked '-'.
- Touch the red ohmmeter lead to terminals AC1, AC2, and AC3; the meter should indicate an open circuit or high resistance.
- Touch the red ohmmeter lead to the rectifier terminal marked '-'.
- Touch the black ohmmeter lead to terminals AC1, AC2, and AC3; the meter should indicate a good diode or low resistance.
- If the meter does not indicate the expected result, the rectifier is bad. Replace the rectifier.
Rotating Rectifier - Test (Brushless Exciter) diagnostic
Tools: 6V-7070 Digital Multimeter, 9U-7330 Multimeter, 146-4080 Digital Multimeter (RS-232), 7X-1710 Multimeter Probe Group
- Remove the cover from the exciter.
- Remove the nut securing the rectifier to the heat sink.
- Remove the diode lead and lift the rectifier from the heat sink.
- Connect ohmmeter leads across the rectifier and note reading.
- Reverse the ohmmeter leads and note reading.
- Low resistance one direction and high the other indicates a good rectifier.
- Low resistance both directions indicates shorted rectifier.
- High resistance both directions indicates open rectifier; replace faulty rectifiers.
Varistor - Test diagnostic
Tools: Ohmmeter, Test Light
- Using an ohmmeter, place the ohmmeter across the varistor. The resistance should be a minimum of 15000 ohms.
- Disconnect either lead of the varistor (CR7).
- Place the test light across the varistor.
- Observe the results. The lamp should not light.
- Reverse the test light.
- Observe the results. The lamp should not light.
- If the test light illuminates in either direction, there is a short in the varistor. Replace any faulty varistors with comparable operating characteristics.
Aftercooler Core - Clean/Test maintenance
⚠ Do not use a high concentration of caustic cleaner to clean the core.
⚠ Maximum air pressure at the nozzle must be less than 205 kPa (30 psi).
Tools: Pressure air supply (maximum 205 kPa / 30 psi at nozzle)
- Remove the core. Refer to the Service Manual for the procedure.
- Turn the aftercooler core upside-down in order to remove debris.
- Back flush the core with cleaner (1U-5490 or 174-6854 Hydrosolv).
- Steam clean the core to remove residue; flush the fins.
- Wash the core with hot, soapy water; rinse thoroughly with clean water.
- Dry the core with compressed air in the reverse direction of normal flow.
- Inspect the core for cleanliness; pressure test; repair if necessary.
- Install the core. Refer to the Service Manual for the procedure.
Battery - Replace maintenance
⚠ Batteries give off combustible gases which can explode.
⚠ Removing cables with cover in place may cause battery explosion.
- Turn key start switch to OFF; remove key and all electrical loads.
- Turn OFF and disconnect battery charger.
- Disconnect NEGATIVE - cable from NEGATIVE - battery terminal.
- Disconnect POSITIVE + cable from POSITIVE + battery terminal.
- Remove the used battery.
- Install the new battery.
- Connect cable from starting motor to POSITIVE + terminal.
- Connect cable from ground plane to NEGATIVE - terminal.
Battery Disconnect Switch - Check maintenance
⚠ Never move the battery disconnect switch to OFF while the engine is operating.
- With switch ON verify electrical components, hour meter and cranking function.
- Turn the battery disconnect switch to the OFF position.
- Verify electrical components, hour meter and cranking do not function.
- Consult your Caterpillar dealer if any item continues to function.
Battery Electrolyte Level - Check maintenance
⚠ All lead-acid batteries contain sulfuric acid; wear face shield and protective clothing.
Tools: 245-5829 Coolant Battery Tester Refractometer
- Remove the filler caps; maintain the electrolyte to the FULL mark.
- Add distilled water if necessary; avoid artificially softened water.
- Check electrolyte condition with the 245-5829 Coolant Battery Tester Refractometer.
- Clean battery case with baking soda/water or ammonia/water solution; rinse.
- Clean terminals and cable clamps with fine grade sandpaper.
- Coat clamps and terminals with 5N-5561 Silicone Lubricant, petroleum jelly or MPGM.
- Clean the battery case; keep the batteries clean.
Bearing (Ball) - Lubricating Process maintenance
Tools: Grease fitting, 8F-9866 Grease gun
- Remove either the louver assembly or the rear plate from the rear of the generator housing.
- Remove the top grease pipe plug and remove the lower grease pipe plug.
- Install a grease fitting in the grease pipe.
- Grease the shielded ball bearings with 2S-3230 Bearing Lubricant (53.28 mL (1.8 ounces) to 59.20 mL (2.0 ounces)).
- Wipe off the excess grease. Remove the top grease fitting. Install the plug.
- Operate the generator for one hour to allow the grease to expand and force excess grease from the cavity.
- Stop the engine. Install the plug in the bottom grease pipe and wipe off the excess grease.
- Install the louver assembly or install the rear plate.
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
Voltage reconnection
| Voltage | Phase | Connection | Leads | Notes |
|---|---|---|---|---|
| 3 | Delta - 6 lead | 6 | Winding pitch must be two-thirds or the generator must be derated. | |
| 3 | Wye - 10 lead (high voltage) | 10 | Illustration 13. Only used on 3306B generator sets and 3406C generator sets. Terminal T0 is the neutral lead. | |
| 3 | Wye - 10 lead (low voltage) | 10 | Only used on 3306B and 3406C generator sets. Terminal T0 is the neutral lead. | |
| 3 | Wye - 12 lead (high voltage) | 12 | Terminals T10, T11, and T12 become neutral connections when tied together. | |
| 3 | Wye - 12 lead (low voltage) | 12 | Terminals T10, T11, and T12 become neutral connections when tied together. | |
| 3 | Wye - 4 lead | 4 | Only used on 3306B generator sets and 3406C generator sets. Terminal T0 is the neutral lead. | |
| 3 | Wye - 6 lead | 6 | Terminals T4, T5, and T6 become neutral connections when the terminals are tied together. | |
| three-phase | 10 Lead Wye Configuration - High Voltage | Terminal T0 is the neutral lead | For 3306B and 3406C generator sets only | |
| three-phase | 10 Lead Wye Configuration - Low Voltage | Terminal T0 is the neutral lead | For 3306B and 3406C generator sets only | |
| three-phase | 12 Lead Delta Configuration | Terminals T6 and T9 become the neutral connection when tied together and grounded; T2 and T10 connection is the high phase | ||
| three-phase | 12 Lead Wye Configuration - High Voltage | Terminals T10, T11 and T12 become neutral connection when tied together | ||
| three-phase | 12 Lead Wye Configuration - Low Voltage | Terminals T10, T11 and T12 become neutral connection when tied together | ||
| three-phase | 4 Lead Wye Configuration | Terminal T0 is the neutral lead | For 3306B and 3406C generator sets only | |
| three-phase | 6 Lead Delta Configuration | |||
| three-phase | 6 Lead Wye Configuration | Terminals T4, T5 and T6 become neutral connection when tied together | ||
| 240 | 3 | Delta - 12 lead | 12 | Terminals T6 and T9 become the neutral connections when tied together and grounded. T2 and T10 connection is the high phase. 240 V, 60 Hz, three-phase: 208 Volts between the high phase and neutral; 240 Volts between either of the low phases and neutral. |
| 240 | three-phase | Delta Configuration (60 Hz, 12 Lead) | T6 and T9 neutral when tied together and grounded | 208 Volts between high phase and neutral; 240 Volts between either low phase and neutral |
| 480 | three-phase | Wye Configuration (typical series Wye, 60 Hz, 12 Lead) | T10, T11, T12 neutral when tied | For 3406E, 3412C and 3500 series generator sets only - high voltage |
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
What is the power rating of the Caterpillar 3412C?
The Caterpillar 3412C is rated 640 kW standby (750.0 kVA).
What engine does the Caterpillar 3412C use?
The Caterpillar 3412C is powered by the Caterpillar 3412C engine.
What fuel does the Caterpillar 3412C use?
The Caterpillar 3412C runs on diesel.
What is the oil capacity of the Caterpillar 3412C?
The Caterpillar 3412C engine in the Caterpillar 3412C has an oil capacity of 139.0 liters.
What oil filter does the Caterpillar 3412C use?
The Caterpillar 3412C uses oil filter part number 1R1808.
What fuel filter does the Caterpillar 3412C use?
The Caterpillar 3412C uses fuel filter part numbers 1R0749, 3089679.
What air filter does the Caterpillar 3412C use?
The Caterpillar 3412C uses air filter part number 4N0015.
Troubleshooting
4Fault codes
| Code | Meaning | Remedy |
|---|---|---|
| i01226491 | Engine overspeed | Stop the engine by shutting off the fuel supply to the engine and/or shutting off the air supply to the engine. |
| 21 | Fault shutdown | |
| 22 | Fault alarm | |
| null | Increased coolant temperature |
Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing.
Parts
110| Part # | Description | Qty | System | |
|---|---|---|---|---|
| 035-8059 | Glow plug | Glow plug | eBay $23.22 FridayParts $13.25 | |
| 102-9720 | Cleaning Kit (detergent and oil for AIRSEP air cleaner elements) | Air filter | eBay | |
| 108-6633 | Fuel pump | Pump | eBay $125.94 FridayParts $105.00 | |
| 110-6326 | Air Primary | 1 | Air filter | Amazon eBay $40.00 KuduParts $30.00 |
| 118-2018 | V-belt | Belt | eBay $74.43 FridayParts $21.56 | |
| 123-2367 | Air Primary | 1 | Air filter | Amazon eBay $89.77 KuduParts $30.00 |
| 133-5673 | Fuel/Water Separator | 1 | Fuel filter | Amazon $47.30 eBay $19.99 eBay $19.99 KuduParts $19.00 |
| 137-1339 | Water pump | Pump | eBay $615.66 FridayParts $488.00 | |
| 138-3100 | Filter water separator | Fuel filter | eBay $14.99 KuduParts $34.00 | |
| 138-6744 | Water pump repair kit | Pump | eBay $179.99 | |
| 142-5867 | Front seal | Seal | eBay $41.66 FridayParts $39.38 | |
| 142-5868 | Rear seal | Seal | eBay $45.71 FridayParts $26.95 | |
| 151-7737 | Air Primary | 1 | Air filter | eBay $100.00 FridayParts $88.99 |
| 161-4113 | Oil pump | Pump | eBay $1200.00 FridayParts $510.00 | |
| 174-6854 | Hydrosolv 100 liquid cleaner, 19 L (5 US gallon) | 1 | Fluid | Amazon eBay |
| 189-0202 | Air Secondary | 1 | Air filter | eBay $60.00 FridayParts $79.99 |
| 1R-0716 | Engine Oil | 1 | Oil filter | Amazon eBay $44.90 eBay $44.90 KuduParts $80.00 |
| 1R-0749 | Fuel Secondary - ADV | 1 | Fuel filter | Amazon $90.99 Amazon $19.99 eBay $135.88 eBay $135.88 KuduParts $17.00 |
| 1R-1808 | Engine Oil - ADV | 2 | Oil filter | Amazon $70.99 eBay $141.00 eBay $59.99 KuduParts $80.00 |
| 1R0716 | Filter oil | Oil filter | Amazon eBay $44.90 eBay $44.90 KuduParts $80.00 | |
| 1R0749 | Filter fuel | Fuel filter | Amazon $90.99 Amazon $19.99 eBay $135.88 eBay $135.88 KuduParts $17.00 | |
| 1R1808 | Filter oil | Oil filter | Amazon $70.99 eBay $141.00 eBay $59.99 KuduParts $80.00 | |
| 1U-5490 | Hydrosolv 4165 liquid cleaner, 19 L (5 US gallon) | 1 | Fluid | Amazon eBay |
| 1U-5492 | Hydrosolv 100 Liquid Cleaner, 19 L (5 US gal) | Fluid | eBay | |
| 1U-5718 | Vacuum Pump | 1 | Pump | Amazon eBay $87.99 |
| 1W1700 | Lift/transfer pump | Pump | eBay $168.00 FridayParts $65.00 | |
| 225-3150 | Starter motor | Starter | eBay $699.99 SinoCMP $289.00 | |
| 339-7767 | Alternator | Alternator | eBay $147.25 FridayParts $157.50 | |
| 3412C | Engine | Engine | Amazon eBay $74.99 FridayParts $18.21 | |
| 384-8611 | Lift/transfer pump | Pump | eBay $358.00 SinoCMP $219.00 | |
| 384-8612 | Lift/transfer pump | Pump | eBay $358.00 KuduParts $148.00 | |
| 3T8705 | Glow plug | Glow plug | eBay $13.99 FridayParts $19.56 | |
| 3T8706 | Glow plug | Glow plug | eBay $33.96 FridayParts $47.99 | |
| 4N0015 | Air filter outer | Air filter | eBay $109.99 KuduParts $114.00 | |
| 4N1151 | Gasket oil pan | Gasket | eBay $15.24 | |
| 4P-7610 | Magnetic Pickup Group (engine speed/timing sensor in flywheel housing) | Sensor | Amazon eBay eBay | |
| 4W8063 | Thermostat | Thermostat | eBay $12.55 FridayParts $18.99 | |
| 5N-5561 | Silicone Lubricant | Fluid | Amazon eBay | |
| 6N6798 | V-belt | Belt | eBay $41.15 | |
| 6T1395 | Alternator | Alternator | eBay $444.93 FridayParts $223.95 | |
| 7C1068 | Water pump impeller | Impeller | eBay $38.95 | |
| 7W-2326 | Engine Oil | 1 | Oil filter | Amazon eBay $24.82 eBay $14.00 KuduParts $25.00 |
| 7W-2327 | Engine Oil | 2 | Oil filter | Amazon eBay $22.00 eBay $22.00 FridayParts $149.99 |
| 7W2327 | Filter oil | Oil filter | Amazon eBay $22.00 eBay $22.00 FridayParts $149.99 | |
| 8S-2245 | Injection Cleaning Tool Group (fuel injection nozzles) | Injector | eBay | |
| 9G8010 | Switch | Sensor | eBay $39.00 FridayParts $16.90 | |
| 9L6639 | V-belt | Belt | eBay $19.99 | |
| 9Y-3879 | Air | 1 | Air filter | eBay $186.50 KuduParts $114.00 |
| ECC328 | Speed Controller | Speed controller | Amazon eBay | |
| PF-300C | Pneumatic Tire | Pump | Amazon eBay $195.60 FridayParts $40.95 | |
| PS-300C | Pneumatic Tire | Pump | Amazon eBay $195.60 FridayParts $99.00 | |
| RE506105 | STARTER (12 V) | Starter | Amazon eBay $146.29 FridayParts $317.99 | |
| RE528929 | STARTER | Starter | Amazon eBay $272.95 FridayParts $241.13 | |
| RE532716 | SHORT BLOCK ASSEMBLY (Also Order Engine Overhaul Gasket Kit and Cylinder Head Bolt Kit) | 1 | Gasket | Amazon eBay |
| SE501853 | STARTER (REMAN FOR RE506105) (12 V) | 1 | Controller | Amazon eBay $307.99 |
| g00283558 | Starting Aid | Starting aid | Amazon eBay | |
| i01377208 | Do not operate the engine unless the instructions and warnings in the Operation and Maintenance Manual are understood. | Warning label | Amazon eBay | |
| 0676879 | Connecting rod | Service part / kit | Amazon eBay $74.38 FridayParts $77.56 | |
| 169-8373 | Fluid Sampling Bottle | 1 | Service part / kit | Amazon eBay $29.99 |
| 2255441 | Connecting rod (Grade L) | Service part / kit | Amazon eBay $68.18 FridayParts $94.00 | |
| 2255453 | Connecting rod (Grade J) | Service part / kit | Amazon eBay $82.72 FridayParts $79.86 | |
| 2255454 | Connecting rod (Grade H) | Service part / kit | Amazon eBay $91.14 FridayParts $104.50 | |
| 249-0439 | Oxidation Catalyst Assembly - Round | Service part / kit | Amazon eBay | |
| 249-0474 | Oxidation Catalyst Assembly - Rectangle | Service part / kit | Amazon eBay | |
| 249-0476 | Oxidation Catalyst Assembly - Rectangle | Service part / kit | Amazon eBay | |
| 249-0477 | Oxidation Catalyst Assembly - Rectangle | Service part / kit | Amazon eBay | |
| 256-0331 | Oxidation Catalyst Assembly - Round | Service part / kit | Amazon eBay | |
| 2562235 | Connecting rod | Service part / kit | Amazon eBay $100.08 | |
| 4C-9301 | Coolant Conditioner Test Kit | Service part / kit | Amazon eBay $30.00 | |
| 5P-3413 | Pipe Sealant for external threads of the zinc rod plug | Service part / kit | eBay $12.37 | |
| 8N1728 | Connecting rod | Service part / kit | Amazon eBay $249.99 | |
| 8T-5296 | Coolant Conditioner Test Kit | 1 | Service part / kit | Amazon eBay eBay |
| 9S-3263 | Compound for the shoulder of a new zinc rod | Service part / kit | eBay $30.78 | |
| C11/C13 | Cat® Engines with ACERT® Technology | Service part / kit | buy | |
| C15/C18 | Cat® Engines with ACERT® Technology | Service part / kit | buy | |
| C27/C32 | Cat® Engines with ACERT® Technology | Service part / kit | buy | |
| C6.6 | Cat® Engines with ACERT® Technology | Service part / kit | KuduParts $130.00 | |
| LEXE0363-00 | January 2012 | Service part / kit | Amazon eBay | |
| QEHQ1025 | Not explicitly stated in the document | Service part / kit | Amazon eBay | |
| QEHQ9778-01 | Replaces QEHQ9778 | 1 | Service part / kit | Amazon eBay |
| QEHQ9995 | Not explicitly stated | 12/03 | Service part / kit | Amazon eBay |
| g00104545 | Illustration 4 | 1 | Service part / kit | Amazon eBay |
| g00107406 | Illustration 1: Safety message for the clutch located on the clutch housing (if equipped). | Service part / kit | Amazon eBay | |
| g00107407 | Illustration 2: Safety message for rotating gears that can cause entanglement of the fingers and hands. | Service part / kit | Amazon eBay | |
| g00283559 | If the engine is equipped with an air inlet heater for cold weather starting, do not use starting aids that contain an aerosol such as ether. | Service part / kit | Amazon eBay | |
| g00294510 | Improper jumper cable connections can cause an explosion resulting in personal injury. | Service part / kit | Amazon eBay | |
| g00687600 | Always use a board or cardboard when you check for a leak. Leaking fluid that is under pressure can penetrate body tissue. | 1 | Service part / kit | Amazon eBay |
| g00702020 | Wear a hard hat, protective glasses, and other protective equipment, as required. | 1 | Service part / kit | Amazon eBay |
| g00702022 | Caterpillar equipment and replacement parts that are shipped from Caterpillar are asbestos free. | 1 | Service part / kit | Amazon eBay |
| g00704000 | Illustration 8 | 1 | Service part / kit | Amazon eBay |
| g00704059 | Illustration 9 | 1 | Service part / kit | Amazon eBay |
| g00704135 | Illustration 10 | 1 | Service part / kit | Amazon eBay |
| g00706404 | Illustration 7 | 1 | Service part / kit | Amazon eBay |
| g01154807 | Typical example | 2 | Service part / kit | Amazon eBay |
| g01154809 | 乙醚警告标签(2) | Service part / kit | Amazon eBay | |
| g01353108 | Illustration 2 - Location and description of warning signs | Service part / kit | Amazon eBay | |
| i01097883 | Important Safety Information | Service part / kit | Amazon eBay | |
| i01359666 | Crushing Prevention and Cutting Prevention | 1 | Service part / kit | Amazon eBay |
| i01372247 | Mounting and Dismounting | 1 | Service part / kit | Amazon eBay |
| i01372262 | Illustration 4: Safety message for flammable fluids and hot surfaces. | Service part / kit | Amazon eBay | |
| i01480768 | Burn Prevention | 1 | Service part / kit | Amazon eBay |
| i01658146 | Important Safety Information | Service part / kit | Amazon eBay | |
| i01805780 | Before Starting Engine | 1 | Service part / kit | Amazon eBay |
| i02136012 | Engine Starting | 1 | Service part / kit | Amazon eBay |
| i02345910 | Do not allow unauthorized personnel on the engine or around the engine when the engine is serviced. | Service part / kit | Amazon eBay | |
| i02469632 | Electrical System | Service part / kit | Amazon eBay | |
| i03560601 | Before Starting Engine | Service part / kit | Amazon eBay | |
| i03684547 | Operation & Maintenance Manual (SEBU7655-01) | Service part / kit | Amazon eBay | |
| i03698546 | Safety Messages | Service part / kit | Amazon eBay | |
| i03704500 | General Hazard Information (Illustration 6) | 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 | 80% | 112.05 | 29.6 |
Available documents
Engine spec — LEHM1063-00 (Caterpillar)Engine spec — LEHM1570-00 (Caterpillar)Engine spec — LEHW8160-00 (Caterpillar)Engine spec — LEHW8161-00 (Caterpillar)Engine spec — lecw2462-06 (Caterpillar)Engine spec — lehh7745 (Caterpillar)Engine spec — lehm6216 (Caterpillar)Engine spec — lehm7231 (Caterpillar)Engine spec — lehm7471 (Caterpillar)Engine spec — lghh6264 (Caterpillar)Engine spec — lshh6264 (Caterpillar)Spec sheet — CAT 3412C Brochure Specifications (Caterpillar)Spec sheet — LEHM1480-00 (Caterpillar)Spec sheet — LEHM1483-00 (Caterpillar)Spec sheet — att Specification sheet (Caterpillar)Operator's manual — 3408C, 3412, 3412C and 3412D High Performance Marine Engines-Engine Safety (Caterpillar)Reference — Aug+2010+Engine+Selection+Guide (Caterpillar)Reference — Caterpillar-Oil-and-Gas-Ratings-Guide-2021-03 (Caterpillar)Reference — Industrial rating guide (Caterpillar)Reference — LECW2462-01 (Caterpillar)Owner's manual — 3408C, 3412, 3412C and 3412D High Performance Marine Engines-Maintenance Intervals (Caterpillar)Owner's manual — CAT-3412C- Generator-Set- Manual (Caterpillar)Owner's manual — OMM SR4 B SEBU6918-03 (Caterpillar)Parts manual — Caterpillar Engines (Caterpillar)Parts manual — KMP-Brand®Parts-Guide-Suitable-for-Caterpillar®By-Product (Caterpillar)Parts manual — LEXE7582-02 (Caterpillar)Service manual — SEBU7125-09+M (Caterpillar)