Cummins Generator Set Filters Guide

Why Cummins Engines Matter for Generator Sets

Cummins, founded in 1919 in Columbus, Indiana, is one of the largest diesel engine makers in the world and a leading name in power generation. Cummins engines power Cummins Power Generation sets and are also widely used by generator packagers and OEMs, so Cummins filter numbers appear on generator sets sold under many brands. Cummins' own filtration brand, Fleetguard, supplies many of the filters used on these engines, which is why Fleetguard numbers are so often used alongside Cummins numbers.

Cummins Engine Series Used in Generator Sets

Cummins Engine Families in Generator Applications

B Series (4BT and 6BT). The 3.9-litre 4BT and 5.9-litre 6BT are among the most common engines in small and mid-size generator sets. They are used in standby and prime gensets across Asia, Africa, Latin America, and the Middle East, and many are still running after decades of service, so replacement filter demand stays high.

C Series (6CT 8.3). The 8.3-litre engine powers mid-range gensets and shares many filters with industrial and truck applications of the same family, which is why numbers such as 3401544 appear in so many catalogs.

L Series (QSL9). The 9-litre QSL9 is a popular choice for generator sets in the 250 to 350 kVA class, including the C275 model, and uses more modern fuel and air filtration than older B and C series engines.

X Series (QSX15). The 15-litre QSX15 powers larger generator sets, such as 500 kVA units, for data centres, industrial sites, and standby power.

K Series (KTA19, KTA38, KTA50, QSK). These large engines power big standby and prime sets, mining sites, and remote power plants. Their filters are larger and more expensive, and the cost of a failed filter or neglected service is correspondingly higher.

Common Cummins Filter OE Numbers for Generator Sets

While exact filter part numbers depend on the specific engine series and build, the following Cummins numbers appear frequently in generator set maintenance:

Oil Filters

• 3932217 (Fleetguard LF3349) – Lube filter listed in Cummins' own spares list for the 6BTA5.9
• 3401544 (Fleetguard LF9009) – A widely used lube filter for 6C8.3, ISC 8.3, QSL9, ISL9, ISM, N14, M11 and NTA855 engines
• LF3000 – Fleetguard lube filter frequently listed alongside 3401544 for larger Cummins engines
• 3101870 and 4016657 – Lube filters for KTA38, KTA50 and QSK series generator engines

Fuel Filters

• 3931063 and 3931065 (Fleetguard FF5052) – Fuel filter for 6BTA5.9 and other B-series generator engines
• FS1235 – Fuel water separator listed for 4BT3.9, 6BT5.9, 6CT8.3 and ISM engines
• 3315844 and 3315845 – Fuel filters for KTA19, K19, QSK19, NT855, N14 and M11 generator engines; 3300901 and 3315804 are also listed

Air Filters

• AF1735K – Air cleaner element listed in Cummins' spares list for the 6BTA5.9
• 4913882 – Air filter for K19, KTA19, QSK38 and QSNT14 generator engines
• 4946497 (0140-3841, Fleetguard AF26173) – Air filter for 500 kVA QSX15-C generator sets
• Fleetguard AF25544 and AF25545 – Air filters for QSL9-G5 and C275 generator sets
• 3688918 (Fleetguard AF55024) – Air filter for L9, QSL9 and QSX15 engines

These numbers are useful references when identifying the correct replacement. Always confirm the exact filter by engine serial number or existing filter part number when possible.

Cummins and Fleetguard Cross-Reference

Many Cummins filters are sold under both a Cummins number and a Fleetguard number. Knowing both makes it much easier to match an old filter to a replacement.

Cummins Power Generation Preventative Maintenance Kits

Cummins Power Generation publishes preventative maintenance kits for many generator models, which bundle the oil, fuel, and air filters. The kit numbers below come from Cummins' own published list and are a useful shortcut.

Cummins Generator Set Filter Maintenance

Oil filters. Replace the lube filter at every oil change. Cummins' own spares list for the 6BTA5.9 shows a service interval of one year or 250 hours, whichever comes first, which is a useful rule of thumb for many B-series and C-series gensets.

Fuel filters. Replace the fuel filter and water separator on schedule. Modern high-pressure common rail systems in larger engines can require filtration as fine as two microns, so fuel filter quality is critical. Drain the separator regularly and prime the system after replacement.

Air filters. Replace the air filter on schedule or when the restriction indicator trips. Cummins offers separate PM kits for normal duty and heavy duty air cleaners on the QSL9, reflecting how much the site environment affects air filter life.

Fleetguard and OE numbers. Many Cummins filters are sold under both a Cummins part number and a Fleetguard number, such as 3932217 and LF3349 or 3931063 and FF5052. They refer to the same filter, and knowing both makes it much easier to find the right replacement.

Standby units. Standby generators run few hours, but oil, fuel, and seals still age. Replace filters at least once a year, and keep fuel clean with regular tank checks.

Service intervals depend on the engine model, oil specification, fuel quality, load profile, and whether the generator set is used for standby, prime, or continuous duty. Always follow the operation and maintenance manual for your specific generator set.

How to Identify the Correct Cummins Filter

• Read the engine serial number (ESN) from the engine data plate, not only the generator nameplate.
• Note the engine family, such as 6BTA5.9-G3 or QSL9-G5, and the build date or configuration.
• Check whether the generator uses a normal duty or heavy duty air cleaner, since this changes the air filter.
• Use both the Cummins number and the Fleetguard number to cross-check the replacement.

Frequently Asked Questions

What oil filter does a Cummins 6BTA5.9 generator use? Cummins' spares list for the 6BTA5.9 shows lube filter 3932217 (Fleetguard LF3349), fuel filter 3931063 (Fleetguard FF5052), and air cleaner AF1735K. Verify against the engine serial number.

What is the difference between 3401544 and LF9009? 3401544 is the Cummins part number and LF9009 is the matching Fleetguard number for the same lube filter, used on engines such as the QSL9, ISC 8.3, ISM and NTA855.

Do Cummins gensets and other brand gensets share filters? Often yes. Cummins engines are used by many generator builders, so the same filters can appear on gensets sold under other names. Always identify the filter by the engine.

Can aftermarket filters be used on Cummins generator sets? Yes, if they meet or exceed the original specification for efficiency, flow, and pressure. For common-rail fuel systems in particular, filtration performance must match the original.

For generator set owners, rental companies, and distributors sourcing replacement filters for Cummins engines and generator sets, ADAOER Filter manufactures fuel, oil, air, and hydraulic filters for generator sets and other diesel machinery, and supports OEM/ODM development for custom specifications. Cross-reference lists are available on request.

Brand names and part numbers are used for identification and compatibility reference only. Caterpillar, Cat, Perkins, Cummins, Fleetguard, and FG Wilson are trademarks of their respective owners. Part numbers vary by engine series, build, and production date, so always verify the correct filter against the engine serial number or the existing filter before ordering.