The Case IH Farmall 100C tractor primary air filter part number is 509-6373. The inner safety filter is AF1980.
Case IH Farmall 100C Air Filter Details
Primary air filter part number
509-6373
Inner safety air filter part number
AF1980
Outer air filter part number
381423R92
Air filter dimensions
Length: 12.5 in | Outside diameter: 6 in | Inside diameter: 2.5 in
Air Filter Service Interval Guide
Air Filter Service Interval Guide
Dusty use
100 hrs
Average
300 hrs
Light use
600 hrs
Listed Filter Size Check
Length
12.5 in
Outside diameter
6 in
Inside diameter
2.5 in
These are practical inspection/replacement guide ranges for the utility tractor category. Dusty work can shorten the interval heavily, so use the restriction indicator and operator manual first.
Case IH Farmall 100C Extra Air Filter Notes
Engine horsepower
99 hp | 73.8 kW
Primary filter note
For the Case IH Farmall 100C, the listed primary air filter part number is 509-6373. Match the number before buying because air cleaner setups can vary by engine, serial range and market.
Outer filter note
The listed outer air filter part number is 381423R92.
Safety filter note
The listed inner safety air filter is AF1980. Do not remove the safety element for normal cleaning; replace it if dirty, damaged or oil-soaked.
Fitment note
Listed dimensions: Length: 12.5 in | Outside diameter: 6 in | Inside diameter: 2.5 in. Use dimensions as a second check, not as the only buying method.
Filter size note
The listed dimensions point to a mid-size element length at 12.5 in and normal outside diameter at 6 in. Use that as a fitment sanity check against the old filter.
Power range note
Use the power class to decide urgency. Higher airflow demand means less patience for questionable media, bad seals or packed pleats.
Service note
Clean loose dust from the air cleaner housing before pulling the filter. Never run the tractor with the filter removed, even for a quick test.
Case IH Farmall 100C Air Filter FAQs
What should I buy for a full Case IH Farmall 100C air-filter service?
For a full parts check, separate the service element from the safety element: buy the outer/primary service element first, then buy the inner safety element only if it is dirty, damaged or due. Do not accidentally order 381423R92 when you meant the safety filter, or AF1980 when you meant the outer filter.
Why should I compare the old Case IH Farmall 100C filter before buying?
Do not buy from the title alone. Match 509-6373 against the removed filter, then check gasket shape, end-cap depth and cover fit before starting the tractor.
Can the Case IH Farmall 100C air filter become a restriction under load?
The combo is a practical warning system. If the element is packed, damaged or not sealing, the engine can lose airflow long before the filter looks catastrophic.
Can I match a Case IH Farmall 100C air filter by size?
A mid-size element can still have different end caps across brands. Use size to narrow the search, then use the part number and seal style to make the decision.
Should I buy separate outer and primary filters for a Case IH Farmall 100C?
The presence of both outer and inner numbers means you should order carefully. A kit can be convenient, but only if it contains the correct service element and safety element.
Why does the full Case IH Farmall 100C air-filter number matter?
The part-number pattern can help spot junk listings. If a seller’s number looks nothing like the catalog style, verify it against a real drawing.
Why not stretch a dirty Case IH Farmall 100C air filter under load?
Use the power class to decide urgency. Higher airflow demand means less patience for questionable media, bad seals or packed pleats.
Official information note
Mistakes do happen. Air filter specs can change by year, engine, serial range, market and air cleaner housing. Check the old filter, operator manual, parts book and official caseih.com website before ordering or installing an air filter.
