The Case IH CS 78 tractor primary air filter part number is 381423R92. The inner safety filter is 371266A1.
Case IH CS 78 Air Filter Details
| Primary air filter part number | 381423R92 |
|---|---|
| Inner safety air filter part number | 371266A1 |
| Outer air filter part number | Same as primary air filter |
Air Filter Service Interval Guide
Air Filter Service Interval Guide
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 CS 78 Extra Air Filter Notes
| Engine model | Sisu 4.4L |
|---|---|
| Engine displacement | 4.2 L | 256.3 cu in |
| Engine horsepower | 78 hp | 58.2 kW |
| Primary filter note | For the Case IH CS 78, the listed primary air filter part number is 381423R92. Match the number before buying because air cleaner setups can vary by engine, serial range and market. |
| Outer filter note | The outer air filter for the Case IH CS 78 appears to be the same listed item as the primary filter. |
| Safety filter note | The listed inner safety air filter is 371266A1. Do not remove the safety element for normal cleaning; replace it if dirty, damaged or oil-soaked. |
| Fitment note | Check the old filter, air cleaner housing label and parts book before ordering if the tractor has had an engine or intake-housing change. |
| Power range note | This sits in the utility range. The 300-hour guide is useful for planning, but dusty work should shorten the inspection cycle. |
| Engine airflow note | A similar horsepower rating does not guarantee the same filter if displacement or engine family changes. Use the engine data as a sanity check only. |
| 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 CS 78 Air Filter FAQs
How do I avoid mixing up the Case IH CS 78 air-filter elements?
For normal service, the primary/outer element is the one that does the dirty work. The inner safety element is backup protection, so replace it less often and keep it seated while cleaning the housing.
What makes the Case IH CS 78 air-filter number risky to order blindly?
The safest match is not just the printed number. Use 381423R92, then check whether the element seats fully without forcing the cover. The outer listing matching the primary means you probably do not need to buy two different outer elements.
Is the Case IH CS 78 outer filter the same as the primary filter?
Do not read the primary and outer rows as two separate filters here. They point to the same service element, with the safety element handled separately.
Why does airflow matter on the Case IH CS 78 air filter?
This sits in the utility range. The 300-hour guide is useful for planning, but dusty work should shorten the inspection cycle.
Why is the exact Case IH CS 78 filter number important?
The primary number looks like a mixed letter-and-number part number. That does not make it automatically correct, but it helps you spot obvious nonsense numbers in search results.
Can similar engines use different Case IH CS 78 air filters?
A similar horsepower rating does not guarantee the same filter if displacement or engine family changes. Use the engine data as a sanity check only.
Is the Case IH CS 78 inner filter a normal service part?
Replace the safety element when it is contaminated, damaged, wet or due by the book. Blowing it out as a normal habit is a dumb way to push dirt toward the engine.
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.
