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Caterpillar 3126B Industrial Engine

Name: Caterpillar 3126B Industrial Engine
Brand: Caterpillar

The Caterpillar 3126B Industrial is a 7.2 L 6-cylinder ataac (air-to-air aftercooled), turbocharged engine rated at 2400 rpm, producing up to 108 kW. It powers generator sets from Caterpillar, including the 3126B. It holds 21 L (5.5 gal) of oil and 13.2 L (3.5 gal) of coolant.

Also known as: Caterpillar 3126B Industrial Engine

7.2 L

Displacement

Cylinders

2400 rpm

Rated speed

108 kW

Gross power

On this pageService parts Specs Generator sets Maintenance Filter cross-reference FAQ Service intervals Torque & specs Fluids Fault codes Procedures

Service parts for the 3126B Industrial

The cheapest captured merchant offer per filter — see the full cross-reference below for every OEM/aftermarket option.

Air intake

1 required

2453818Air filterfind

Fuel system

1 required

1165436Fuel filtersee priceAmazon

Oil system

1 required

0773673Oil filterfind

Cooling system

1 required

3I1288Coolant filterfind

Prices captured from merchant listings; some links are affiliate links. Verify against your serial number before ordering.

Engine specifications

Oil capacity	21.0 L
Coolant capacity	13.2 L
Displacement	7.2 L
Cylinders	6
Aspiration	ATAAC (Air-to-air aftercooled), Turbocharged
Rated speed	2400 rpm
Gross power	108 kW

Generator sets powered by this engine

Caterpillar 3126B

How to read your Caterpillar engine serial & model number →

Common problems

The “DIAGNOSTIC” lamp flashes in order to indicate a two-digit code. Diagnostic Flash Code
The “DIAGNOSTIC” lamp flashes codes for any active diagnostic codes. 1000; 1900; 1901; 1902
Reduced Engine Speed
Fix: Shut down the Engine(1); Service(2); Schedule Service for the Engine.(3)
Overspeed condition during initial start-up or overhauled engine
Fix: Stop the engine by shutting off the fuel supply to the engine and/or shutting off the air supply to the engine.
Low Power
Fix: Check the adjustments for the Throttle Position Sensor.
Loose or frayed electrical wires
Fix: Check the electrical wires daily for wires that are loose or frayed. Tighten all loose electrical wires before the engine is started. Repair all frayed electrical wires before the engine is started. See the Operation and Maintenance Manual for specific starting instructions.
Improper grounding
Fix: Proper grounding for the engine electrical system is necessary for optimum engine performance and reliability. Improper grounding will result in uncontrolled electrical circuit paths and in unreliable electrical circuit paths. Uncontrolled electrical circuit paths can result in damage to main bearings, to crankshaft bearing journal surfaces, and to aluminum components. Engines that are installed without engine-to-frame ground straps can be damaged by electrical discharge. To ensure that the engine and the engine electrical systems function properly, an engine-to-frame ground strap with a direct path to the battery must be used. This path may be provided by way of a direct engine ground to the frame. All grounds should be tight and free of corrosion. The engine alternator must be grounded to the negative “-” battery terminal with a wire that is adequate to handle the full charging current of the alternator.
If the ECM does not receive a signal from primary speed/timing sensor (6), the “DIAGNOSTIC” lamp will indicate a diagnostic fault code which will be logged in the ECM memory.
Fix: The ECM will read the signal from the secondary speed/timing sensor. The ECM continually checks in order to determine if there is a signal from both sensors. If either sensor fails, the faulty sensor should be replaced. Intermittent failure of the sensors will cause erratic engine control.
Fault Logging i01463504
Fix: The system provides the capability of Fault Logging. When the Electronic Control Module (ECM) generates an active diagnostic code, the code will be logged in the memory of the ECM.
Failure of the Engine Oil Pressure Sensor will not cause a shutdown of the engine or any horsepower change.
Cause: The ECM will detect failure of the engine oil pressure sensor. The diagnostic lamp warns the user about the status of the engine oil pressure sensor. The engine oil pressure related strategies will be disabled in the event of a failure of the engine oil pressure sensor.
Failure of the Coolant Temperature Sensor will not cause a shutdown of the engine or any horsepower change.
Cause: The ECM will detect a failure of the coolant temperature sensor. The diagnostic lamp will warn the operator about the status of the coolant temperature sensor.
Failure of the Boost Pressure Sensor will not cause a shutdown of the engine.
Cause: The ECM will detect failure of the boost pressure sensor. The operator will be warned of the problem through the diagnostic lamp. The strategies that are related to the boost will be disabled. Engine power will be severely reduced in the event of a failure of the boost pressure sensor.
Excessive Smoke
Fix: The operator should log any observation that could have caused the lamp to light. This information can be useful to help troubleshoot the situation.
Engine Stopping i01462046
Fix: Stop the engine according to the procedure in the Operation and Maintenance Manual, “Engine Stopping (Operation Section)” in order to avoid overheating of the engine and accelerated wear of the engine components. Use the Emergency Stop Button (if equipped) ONLY in an emergency situation. Do not use the Emergency Stop Button for normal engine stopping. After an emergency stop, DO NOT start the engine until the problem that caused the emergency stop has been corrected.
Engine Operation with Intermittent Diagnostic Codes i01456915
Fix: If the diagnostic lamp starts to flash codes during normal engine operation and the diagnostic lamp shuts off, an intermittent fault may have occurred. If a fault has occurred, the fault will be logged into the memory of the Electronic Control Module (ECM).

Compiled from service & troubleshooting documentation across every generator set that uses the Caterpillar 3126B Industrial.

Maintenance schedule

Item	Part #
Air filter	—
Fuel filter	—
Oil filter	—
Battery	—
Belt	—
Coolant	—
Coolant filter	24071	Amazon eBay $10.00 PartsGeek $14.97
Oil	—
Spark plug	—

Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.

Service intervals

Item	Action	Hours	Months	Notes
Air Compressor	Inspect	250 hr	6 mo	PM Level 1 - Every 6625 L (1750 US gal) of Fuel or 250 Service Hours or 6 Months
Air Compressor Filter	Clean	250 hr	6 mo	PM Level 1 - Clean/Replace
Alternator	Inspect	250 hr	6 mo	PM Level 1
Battery Electrolyte Level	Check	250 hr	6 mo	PM Level 1
Cooling System Supplemental Coolant Additive (SCA)	Test	250 hr	6 mo	PM Level 1 - Test/Add
Cylinder Head Grounding Stud	Inspect	250 hr	6 mo	PM Level 1 - Inspect/Clean/Tighten
Engine Crankcase Breather	Clean	250 hr	6 mo	PM Level 1
Engine Oil Sample	Other	250 hr	6 mo	PM Level 1 - Obtain
Engine Oil and Filter	Change	500 hr	6 mo	PM Level 1 - Every 6625 L (1750 US gal) of Fuel or 250 Service Hours or 6 Months (shallow sump)
Fan Drive Bearing	Lubricate	250 hr	6 mo	PM Level 1
Fuel Tank Water and Sediment	Drain	250 hr	6 mo	PM Level 1
Hoses and Clamps	Inspect	250 hr	6 mo	PM Level 1 - Inspect/Replace
Radiator	Clean	250 hr	6 mo	PM Level 1
Engine crankcase (S·O·S Oil Analysis)	Other	500 hr		S·O·S Oil Analysis Interval - Every 500 Service Hours
2007 C7/C9 CCV (Closed Crankcase Ventilation)	Other	1500 hr		Maintenance Intervals for 2007 Engines Only - or 3rd oil change or 90,000 miles
CRS Nozzle Cleaning	Clean	1500 hr		Maintenance Intervals for 2007 Engines Only - or 50,000 miles
Spark Plug Inspection/Cleaning	Inspect	1500 hr		Maintenance Intervals for 2007 Engines Only - or 3rd oil change or 90,000 miles
Aftercooler Core	Clean	2000 hr	12 mo	PM Level 2 - Every 52990 L (14000 US gal) of Fuel or 2000 Service Hours or 1 Year - Clean/Test
Engine Valve Lash	Adjust	2000 hr	12 mo	First service — PM Level 2 - Inspect/Adjust
Oil	Change	2000 hr	24 mo	PM 1 Recommended Change Intervals: 2 Years / 100,000 Miles / 2,000 Hours
Oil and filter	Change	2000 hr	24 mo	PM Level 1; recommended change intervals: 2 years, 100,000 miles, 2,000 hours
Cooling System Coolant (DEAC)	Change	3000 hr	36 mo	Every 3000 Service Hours or 3 Years
Belt Tensioner	Inspect	4000 hr	24 mo	PM Level 3 - Every 105980 L (28000 US gal) of Fuel or 4000 Service Hours or 2 Years
Cooling System Coolant Extender (ELC)	Other	4000 hr	24 mo	PM Level 3 - Add
Cooling System Water Temperature Regulator	Replace	4000 hr	24 mo	PM Level 3
Crankshaft Vibration Damper	Inspect	4000 hr	24 mo	PM Level 3
Engine	Clean	4000 hr	24 mo	PM Level 3
Engine Mounts	Inspect	4000 hr	24 mo	PM Level 3
Starting Motor	Inspect	5000 hr		Every 132475 L (35000 US gal) of Fuel or 5000 Service Hours
Turbocharger	Inspect	5000 hr		Every 132475 L (35000 US gal) of Fuel or 5000 Service Hours - Inspect/Clean
Water Pump	Inspect	5000 hr		Every 132475 L (35000 US gal) of Fuel or 5000 Service Hours
Cooling System Coolant (ELC)	Change	6000 hr	72 mo	Every 6000 Service Hours or 6 Years
minor overhaul	Other	20000 hr		3600 engines designed to run 20 000 hours between minor overhauls using No. 2 fuel
major overhaul	Other	40000 hr		3600 engines designed to run 40 000 hours between major overhauls using No. 2 fuel
cylinder liners and pistons	Other	80000 hr		3600 cylinder liners and pistons designed for 80 000 hours using No. 2 fuel
Belt	Inspect	250 hr	6 mo	First service — Initial 20 to 40 Service Hours
Engine oil	Change		12 mo	26L (28 quarts) oil pan: 15,000 miles/1 year
Thermostats	Replace		36 mo	Replace every three years
Valve adjustment	Adjust			First service — PM Level 2 - initial valve adjustment around 30,000 miles for optimum engine performance

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

Type	Item	Value	Unit	Condition
Clearance	Belt deflection at 110 N (25 lb ft) force midway between pulleys	9 to 15	mm	engine stopped
Other	Ammeter	Slightly Positive		gauge range
Other	Oil pressure rise time after start	15	seconds	oil pressure should rise within 15 seconds after engine starts
Pressure	Atmospheric Pressure Sensor operating pressure range	0 to 116	kPa
Pressure	Boost	0 – 28	psi
Pressure	Engine Oil Pressure Sensor operating pressure range	0 to 690	kPa
Pressure	Engine Oil Pressure at rated speed with SAE 10W30 or SAE 15W40	240 to 480	kPa	rated speed
Pressure	Oil pressure low warning setpoint (diagnostic lamp)	35	kPa	low idle rpm
Pressure	Unit injector fuel injection pressure	1240	bar (18 000 psi)
Speed	Cold Idle	1000	rpm
Speed	Cold start strategy ECM idle rpm	800	rpm	cold engine start
Speed	Tachometer	700 – 2620	rpm	gauge range
Speed	Warm Idle	700 – 800	rpm
Temperature	Air inlet heater turns OFF when sum of coolant temp and air inlet temp exceeds	35	°C
Temperature	Coolant Temperature	180 – 215	°F	gauge range
Temperature	Engine Oil Temperature Sensor operating temperature range	-40 to 120	°C
Temperature	High coolant temperature fault activation temperature	103	°C
Temperature	Inlet Air Temperature Sensor operating temperature range	-40 to 120	°C
Temperature	Inlet manifold air temperature limit	75	°C
Temperature	Jacket Water Coolant Temperature (typical)	88 to 102	°C
Temperature	Maximum allowable coolant temperature (pressurized cooling system)	105	°C
Temperature	Very high coolant temperature fault activation temperature	106	°C
Torque	Constant Torque Hose Clamp - belleville washers collapsed	11 ± 1	N·m	screw tightened until belleville washers collapse nearly flat
Torque	Engine Air Cleaner Service Indicator installation torque	2	N·m
Torque	Inch Nuts and Bolts 1	900 ± 100	N·m
Torque	Inch Nuts and Bolts 1 1/2	3100 ± 350	N·m
Torque	Inch Nuts and Bolts 1 1/4	1800 ± 200	N·m
Torque	Inch Nuts and Bolts 1 1/8	1300 ± 150	N·m
Torque	Inch Nuts and Bolts 1 3/8	2400 ± 300	N·m
Torque	Inch Nuts and Bolts 1/2	105 ± 20	N·m
Torque	Inch Nuts and Bolts 1/4	12 ± 3	N·m
Torque	Inch Nuts and Bolts 3/4	370 ± 50	N·m
Torque	Inch Nuts and Bolts 3/8	47 ± 9	N·m
Torque	Inch Nuts and Bolts 5/16	25 ± 6	N·m
Torque	Inch Nuts and Bolts 5/8	215 ± 40	N·m
Torque	Inch Nuts and Bolts 7/16	70 ± 15	N·m
Torque	Inch Nuts and Bolts 7/8	620 ± 80	N·m
Torque	Inch Nuts and Bolts 9/16	160 ± 30	N·m
Torque	Inch Taperlock Studs 1	400 ± 60	N·m
Torque	Inch Taperlock Studs 1 1/2	1200 ± 150	N·m
Torque	Inch Taperlock Studs 1 1/4	750 ± 80	N·m
Torque	Inch Taperlock Studs 1 1/8	525 ± 60	N·m
Torque	Inch Taperlock Studs 1 3/8	950 ± 125	N·m
Torque	Inch Taperlock Studs 1/2	65 ± 10	N·m
Torque	Inch Taperlock Studs 1/4	8 ± 3	N·m
Torque	Inch Taperlock Studs 3/4	170 ± 30	N·m
Torque	Inch Taperlock Studs 3/8	35 ± 5	N·m
Torque	Inch Taperlock Studs 5/16	17 ± 5	N·m
Torque	Inch Taperlock Studs 5/8	110 ± 20	N·m
Torque	Inch Taperlock Studs 7/16	45 ± 10	N·m
Torque	Inch Taperlock Studs 7/8	260 ± 40	N·m
Torque	Metric Nuts and Bolts M10	55 ± 10	N·m
Torque	Metric Nuts and Bolts M12	100 ± 20	N·m
Torque	Metric Nuts and Bolts M14	160 ± 30	N·m
Torque	Metric Nuts and Bolts M16	240 ± 40	N·m
Torque	Metric Nuts and Bolts M20	460 ± 60	N·m
Torque	Metric Nuts and Bolts M24	800 ± 100	N·m
Torque	Metric Nuts and Bolts M30	1600 ± 200	N·m
Torque	Metric Nuts and Bolts M36	2700 ± 300	N·m
Torque	Metric Nuts and Bolts M6	12 ± 3	N·m

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		TMC RP329, ASTM D5345, or D4985			Antifreeze must be a low silicate type. DO NOT use commercial antifreeze with high silicate content formulated for gasoline engines. Use only distilled or deionized water. Do not mix different antifreeze and conditioners. Use conditioner or inhibitor to maintain a three to six percent concentration. Requirements are different for ELC — consult your dealer.
Coolant	Cat DEAC				Diesel; 3,000 Service Hours or Three Years; annual S·O·SSM Level 2 coolant sampling and analysis
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 Extended Life Coolant (ELC)	Cat EC-1			6-year life. Recommended 50/50 glycol water coolant mixture. Cat Extender added at 3 years.
Coolant	Cat NGEC				Natural Gas; 16,000 Service Hours or Three Years; use interval that occurs first
Coolant	Caterpillar Diesel Engine Antifreeze/Coolant (DEAC)	ASTM D4985 or ASTM D5345			Acceptable coolant; 3000 Service Hours or Three Years service life
Coolant	Caterpillar Extended Life Coolant (ELC) or commercial EC-1	Caterpillar EC-1			Preferred coolant; 1:1 mixture of water and glycol; 6000 Service Hours or Six Years service life
Coolant	Caterpillar SCA and Water				Six to eight percent concentration of SCA recommended for stationary/marine applications without anti-boil or freeze protection; 3000 Service Hours or Two Years
Coolant	60% antifreeze/40% water		above -51°C		Antifreeze Protection — To -60° F (-51° C)
Coolant	50% antifreeze/50% water		above -37°C		Antifreeze Protection — To -34° F (-37° C)
Coolant	Propylene Glycol 50 Percent	Caterpillar ELC / DEAC	above 29°C		Freeze protection -29 °C (-20 °F); Boil protection 106 °C (223 °F)
Coolant	Ethylene Glycol 50 Percent	Caterpillar ELC / DEAC	above 36°C		Freeze protection -36 °C (-33 °F); Boil protection 106 °C (223 °F)
Coolant	Ethylene Glycol 60 Percent	Caterpillar ELC / DEAC	above 51°C		Freeze protection -51 °C (-60 °F); Boil protection 111 °C (232 °F)
Engine oil	Cat NGEO				Natural Gas
Engine oil	Caterpillar Diesel Engine Oil (10W30)	EMA LRG-1 / API CH-4 / API CG-4 / API CF-4		21.0 L	Approximate crankcase refill capacity, shallow oil sump, includes standard oil filters. Deep oil sump 31 L
Engine oil	SAE 10W30	API CJ-4			Temperature Range -4° F to +104° F. Cat DEO. Below 0° F, block heater or oil pan heater is recommended.
Engine oil	SAE 15W40	API CJ-4			Temperature Range +5° F to +122° F. Cat DEO. Below 0° F, block heater or oil pan heater is recommended.
Engine oil	Cat Arctic DEO SYN SAE 0W-30		-40°C to 30°C		Engine Crankcase; Industrial Engines
Engine oil	Cat DEO SYN SAE 5W-40		-30°C to 50°C		Engine Crankcase; Industrial Engines
Engine oil	Cat DEO SAE 10W-30		-18°C to 40°C		Engine Crankcase; Industrial Engines
Engine oil	Cat DEO SAE 15W-40		-9°C to 50°C		Engine Crankcase; Industrial Engines
Engine oil	SAE 5W30	Caterpillar DEO Multigrade / EMA LRG-1 / API CH-4 / API CG-4 / API CF-4	30°C to 30°C
Engine oil	SAE 5W40	Caterpillar DEO Multigrade / EMA LRG-1 / API CH-4 / API CG-4 / API CF-4	30°C to 40°C
Engine oil	SAE 0W20	Caterpillar DEO Multigrade / EMA LRG-1 / API CH-4 / API CG-4 / API CF-4	40°C to 10°C		Engine Oil Viscosity Table 14
Engine oil	SAE 0W30	Caterpillar DEO Multigrade / EMA LRG-1 / API CH-4 / API CG-4 / API CF-4	40°C to 30°C
Engine oil	SAE 0W40	Caterpillar DEO Multigrade / EMA LRG-1 / API CH-4 / API CG-4 / API CF-4	40°C to 40°C
Fuel	Blend of No. 1 and No. 2 diesel fuel	ASTM D975			Best suited for cold weather operation
Fuel	No. 1 diesel fuel	ASTM D975			Best suited for cold weather operation
Fuel	No. 2 diesel fuel	ASTM D975			Most commonly used fuel
Fuel	No. 2 fuel				3600 engines designed for 80 000 hours on No. 2 fuel; ratings based on API gravity of 35 at 15 C (60 F), LHV of 42 780 kJ/kg used at 29 C (84 F) with a density of 838.9 g/L

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Fault codes

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Procedures

Belt - Inspect (Adjustment) adjustment

⚠ Replace belts that are worn or damaged. Replace multiple drive belts in matched sets.

Check belt tension initially between the first 20 to 40 hours of engine operation, with the engine stopped.
Apply 110 N (25 lb ft) of force midway between the pulleys; a correctly adjusted belt will deflect 9 mm (0.35 inch) to 15 mm (0.59 inch).
For alternator belt: slightly loosen mounting bolts and adjusting bolt, move pulley to adjust tension, then tighten.
For water pump belt: slightly loosen mounting bolt and adjusting bolt, adjust tension with a square drive in square hole, then tighten.
Install the belt guard.
If new belts are installed, check tension again after 30 minutes of operation at rated rpm.

Engine Valve Lash - Inspect/Adjust adjustment

⚠ Only qualified service personnel should perform this maintenance.

⚠ Do not use the starting motor to turn the flywheel.

⚠ Hot engine components can cause burns.

Ensure that the engine can not be started while this maintenance is being performed.
Allow the engine to cool before measuring/adjusting valve lash clearance.
Ensure the engine is stopped before measuring the valve lash.
Refer to the Service Manual for the complete valve lash adjustment procedure.

Engine Diagnostics (Flash Codes) diagnostic

Turn cruise control switch to OFF position.
Move SET/RESUME switch to either position and hold.
Record two-digit flash codes: short pause between digits, long pause between codes.
Refer to Engine Diagnostics table in the O & M manual and consult your local Caterpillar dealer.

Aftercooler Core - Clean/Test maintenance

⚠ Do not use a high concentration of caustic cleaner to clean the core.

⚠ Personal injury can result from air pressure.

Remove the core. Refer to the Service Manual.
Turn the aftercooler core upside-down in order to remove debris.
Back flush the core with cleaner. Caterpillar recommends Hydrosolv liquid cleaner.
Steam clean the core to remove any residue. Flush the fins. Remove any other trapped debris.
Wash the core with hot, soapy water. Rinse thoroughly with clean water.
Dry the core with compressed air, directing the air in reverse of normal flow.
Inspect the core for cleanliness. Pressure test the core. Repair if necessary.
Install the core. Refer to the Service Manual.

Battery - Replace maintenance

⚠ Batteries give off combustible gases which can explode.

⚠ The battery cover should be removed before any servicing is attempted.

Turn the key start switch to the OFF position. Remove the key and all electrical loads.
Turn OFF the battery charger. Disconnect the charger.
Disconnect the NEGATIVE "-" cable from the NEGATIVE "-" battery terminal.
Disconnect the POSITIVE "+" cable from the POSITIVE "+" battery terminal.
Remove the used battery.
Install the new battery.
Connect the cable from the starting motor to the POSITIVE "+" battery terminal.
Connect the cable from the ground plane to the NEGATIVE "-" battery terminal.

Battery Electrolyte Level - Check maintenance

⚠ All lead-acid batteries contain sulfuric acid which can burn the skin and clothing. Always wear a face shield and protective clothing.

Tools: 1U-7298 Coolant/Battery Tester (°C), 1U-7297 Coolant/Battery Tester (°F)

Remove the filler caps. Maintain the electrolyte level to the "FULL" mark on the battery.
Add distilled water if necessary; do not use artificially softened water.
Check the condition of the electrolyte with the 1U-7298 or 1U-7297 Coolant/Battery Tester.
Keep the batteries clean.
Clean the battery case with a baking soda/water or ammonia/water solution and rinse.
Clean the terminals and cable clamps; coat with 5N-5561 Silicone Lubricant, petroleum jelly or MPGM grease.

Changing to Caterpillar ELC maintenance

⚠ Do not leave an empty SCA filter on an ELC system.

⚠ Improper or incomplete rinsing of the cooling system can result in damage to copper and other metal components.

Drain the coolant into a suitable container.
Dispose of the coolant according to local regulations.
Remove the empty SCA filter and remove the filter base. Plug the coolant lines or bypass the coolant lines.
Flush the system with clean water in order to remove any debris.
Use Caterpillar cleaner to clean the system. Follow the instruction on the label.
Drain the cleaner into a suitable container. Flush the cooling system with clean water.
Fill the cooling system with clean water and operate the engine until warmed to 49° to 66°C (120° to 150°F).
Drain the cooling system and flush with clean water.
Repeat the fill/flush steps until the system is completely clean.
Fill the cooling system with the Caterpillar premixed ELC.
Attach the Label (PEEP5027) to the cooling system filler to indicate use of Caterpillar ELC.

Cleaning the Primary Air Cleaner Elements maintenance

⚠ Do not tap or strike the filter element.

⚠ Do not wash the filter element.

Tools: 60 watt blue light

Visually inspect the primary element before cleaning; discard damaged elements.
Pressurized air: use filtered, dry air with a maximum pressure of 207 kPa (30 psi); begin with the clean side (inside).
Aim the hose so air flows inside the element along the length of the filter.
Vacuum cleaning: recommended prior to vacuum cleaning; will not remove carbon and oil deposits.
Inspect the clean, dry element with a 60 watt blue light in a dark room for tears or holes.
Discard any element that has tears, holes, or damaged pleats, gaskets or seals.
Store unused elements wrapped in Volatile Corrosion Inhibited (VCI) paper in a dry location.

Cooling System Coolant (DEAC) - Change maintenance

⚠ Pressurized System: Hot coolant can cause serious burns.

⚠ Never add coolant to an overheated engine.

Tools: 9S-8140 Pressurizing Pump

Stop the engine and allow the engine to cool. Loosen the filler cap slowly to relieve pressure. Remove the filler cap.
Open the cooling system drain valve (or remove a drain plug). Allow the coolant to drain.
Flush the cooling system with clean water to remove debris.
Close the drain valve; clean and install the drain plugs.
Fill with clean water and Caterpillar Fast Acting Cooling System Cleaner (0.5 L per 15 L capacity). Install filler cap.
Start and run the engine at low idle for a minimum of 30 minutes; coolant temperature at least 82 °C (180 °F).
Stop engine, cool, drain and flush with clean water. Close drain and install drain plugs.
Fill the cooling system with coolant/antifreeze. Do not install the filler cap.
Start and run engine at low idle; increase to 1500 rpm; run at high idle one minute to purge air. Stop engine.
Check coolant level to within 13 mm (0.5 inch) below the bottom of the filler pipe.
Clean and inspect the filler cap gasket. Pressure test the cap with a 9S-8140 Pressurizing Pump.
Start the engine. Inspect the cooling system for leaks and proper operating temperature.

Cooling System Coolant (ELC) - Change maintenance

⚠ Pressurized System: Hot coolant can cause serious burns.

Tools: 9S-8140 Pressurizing Pump

Stop the engine and allow the engine to cool. Loosen the filler cap slowly to relieve pressure. Remove the filler cap.
Open the drain valve (or remove drain plugs) and allow the coolant to drain.
Flush the cooling system with clean water to remove debris.
Close the drain valve; clean and install the drain plugs.
Fill with clean water. Install the filler cap.
Start and run the engine at low idle until temperature reaches 49 to 66 °C (120 to 150 °F).
Stop engine, cool, drain and flush with clean water. Close drain and install drain plugs.
Fill the cooling system with Extended Life Coolant (ELC). Do not install the filler cap.
Start and run engine at low idle; increase to high idle; run one minute to purge air. Stop engine.
Check coolant level to within 13 mm (0.5 inch) below the bottom of the filler pipe.
Clean and inspect the filler cap gasket; pressure test with a 9S-8140 Pressurizing Pump.
Start the engine. Inspect the cooling system for leaks and proper operating temperature.

Cooling System Recommendations maintenance

⚠ DO NOT use commercial antifreeze with high silicate content formulated for gasoline engines.

Use only distilled or deionized water.
Antifreeze must be a low silicate type that meets TMC RP329, ASTM D5345, or D4985 specifications. DO NOT use commercial antifreeze with high silicate content formulated for gasoline engines.
Use conditioner or inhibitor to maintain a three to six percent concentration in cooling system. Requirements are different for ELC (Extended Life Coolant) — consult your dealer.
Do not mix different antifreeze and conditioners.
Cat ELC recommended for six-year protection. Meets Cat EC-1 specification.

Engine Air Cleaner Element (Dual Element) - Clean/Replace maintenance

⚠ Never run the engine without an air cleaner element installed.

⚠ Never service the air cleaner element with the engine running.

Remove the cover. Remove the primary air cleaner element.
Remove and discard the secondary element for every three cleanings of the primary element.
Cover the turbocharger air inlet with tape to keep dirt out.
Clean the inside of the air cleaner cover and body with a clean, dry cloth.
Remove the tape. Install the secondary air cleaner element. Install a new or cleaned primary element.
Install the air cleaner cover.
Reset the air cleaner service indicator.

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Filters for this engine

Air filter: Caterpillar 2453818 Caterpillar 1318221 Caterpillar 30009151 Caterpillar 2456375 Caterpillar 2456376 Caterpillar 3I1550 Caterpillar 1282686 Caterpillar 6I2502
Coolant filter: Caterpillar 3I1288 Caterpillar 9N3366 Donaldson P552071 Donaldson P554071 Wix 24071 Ac Delco WF4
Fuel filter: Caterpillar 1165436 Caterpillar 2568753 Caterpillar 5134490 Caterpillar 1R0753 Caterpillar 1466695 Caterpillar 3I1253 Donaldson P550625 Donaldson P551000
Oil filter: Caterpillar 0773673 Caterpillar IR1807 Caterpillar 3890434 Caterpillar 492164004 Caterpillar 1W3300 Donaldson P550008 Donaldson P551807 Donaldson P551808

Cross-referenced via Donaldson + OEM/engine-maker interchange — options to verify against your serial number, not confirmed for every exact variant.

Also used in

Caterpillar 533 — Forestry Equipment
Caterpillar 543 — Forestry Equipment
Caterpillar D5N LGP — Tractor Tracked
Caterpillar D5N XL — Tractor Tracked
Caterpillar TK370 — Feller Buncher
Caterpillar TK380 — Feller Buncher
Claas LEXION 510 — Combine
Claas LEXION 520 — Combine
Claas LEXION 520 MONTANA — Combine
Claas LEXION 530 — Combine
Claas LEXION 530 MONTANA — Combine
Claas LEXION 540C — Combine

Other equipment known to use this engine, via filter-application cross-reference — useful for sourcing parts even when your exact machine isn't listed elsewhere on this page.

Common questions

What is the oil capacity of the Caterpillar 3126B Industrial?

The Caterpillar 3126B Industrial engine has an oil capacity of 21.0 liters.

What is the displacement of the Caterpillar 3126B Industrial?

The Caterpillar 3126B Industrial has a displacement of 7.2 liters with 6 cylinders.

Which generators use the Caterpillar 3126B Industrial engine?

The Caterpillar 3126B Industrial powers 1 generator set(s), including Caterpillar 3126B.

What oil filter does the Caterpillar 3126B Industrial use?

The Caterpillar 3126B Industrial uses oil filter part numbers Caterpillar 0773673, Caterpillar IR1807, Caterpillar 3890434.

What fuel filter does the Caterpillar 3126B Industrial use?

The Caterpillar 3126B Industrial uses fuel filter part numbers Caterpillar 1165436, Caterpillar 2568753, Caterpillar 5134490.

What air filter does the Caterpillar 3126B Industrial use?

The Caterpillar 3126B Industrial uses air filter part numbers Caterpillar 2453818, Caterpillar 1318221, Caterpillar 30009151.

What is a common problem with the Caterpillar 3126B Industrial engine?

A commonly reported issue on generators using the Caterpillar 3126B Industrial is: The “DIAGNOSTIC” lamp flashes in order to indicate a two-digit code..

Code	Name	Meaning	Severity	Action
13	Fault for the Fuel Temperature Sensor	Fault for the Fuel Temperature Sensor
15	Open or Short Circuit of Injection Actuation Pressure Sensor	Open or Short Circuit of Injection Actuation Pressure Sensor
17	High Injection Actuation Pressure	High Injection Actuation Pressure
18	Open or Short for the Injection Actuation Pressure Control Valve	Open or Short for the Injection Actuation Pressure Control Valve
21	Sensor Supply Voltage Above Normal or Below Normal	Sensor Supply Voltage Above Normal or Below Normal
24	Oil Pressure Sensor Fault	Oil Pressure Sensor Fault
25	Inlet Manifold Air Pressure Sensor Fault	Inlet Manifold Air Pressure Sensor Fault
26	Atmospheric Pressure Sensor Fault	Atmospheric Pressure Sensor Fault
27	Coolant Temperature Sensor Fault	Coolant Temperature Sensor Fault
28	Check the Adjustments for the Throttle Position Sensor	Check the Adjustments for the Throttle Position Sensor
34	Loss Of Engine RPM Signal	Loss Of Engine RPM Signal
35	Event for Engine Overspeed	Event for Engine Overspeed
37	Fuel Pressure Sensor Fault	Fuel Pressure Sensor Fault
38	Inlet Manifold Air Temperature Sensor Fault	Inlet Manifold Air Temperature Sensor Fault
39	Mechanical Failure of the Injection Actuation Pressure Sensor	Mechanical Failure of the Injection Actuation Pressure Sensor
42	Check the Calibration of the Timing Sensor	Check the Calibration of the Timing Sensor
46	Low Oil Pressure Event	Low Oil Pressure Event		Shut down the Engine: Operate the engine cautiously. Get immediate service. Severe engine damage may result.
51	Intermittent Battery Power to the ECM	Intermittent Battery Power to the ECM
52	Personality Module Fault	Personality Module Fault
55	No Detected Faults	Flash code 55 is “No Detected Faults.”	Info	Refer to Engine Diagnostics table in the O & M manual and consult your local Caterpillar dealer.
56	The following parameters must be checked: Customer and System	The following parameters must be checked: Customer and System
59	Incorrect Engine Software	Incorrect Engine Software
61	Event for High Coolant Temperature	Event for High Coolant Temperature
62	Event for Low Coolant Level	Event for Low Coolant Level
63	Low Fuel Pressure Event	Low Fuel Pressure Event
64	Event for High Inlet Manifold Air Temperature	Event for High Inlet Manifold Air Temperature
65	Event for High Fuel Temperature	Event for High Fuel Temperature
72	Fault of Cylinder 1 or Cylinder 2	Fault of Cylinder 1 or Cylinder 2
73	Fault of Cylinder 3 or Cylinder 4	Fault of Cylinder 3 or Cylinder 4
74	Fault of Cylinder 5 or Cylinder 6	Fault of Cylinder 5 or Cylinder 6