110-6326 and 110-6331 Air Filters: Primary and Secondary Ordering Guide
2026/09/19
110-6326 and 110-6331 should not be treated as two interchangeable spellings of one air filter. Caterpillar identifies 110-6326 as an air-cleaner primary element and 110-6331 as a secondary engine air filter. When both are needed, put them on separate quotation lines with a quantity for each.
Our 110-6326 / 110-6331 air-filter listing shows a pair of elements. The photographs help compare their physical arrangement, but the individual labels and package contents should still be confirmed for the supplied pair.
Why does the primary or secondary description matter?
The two references identify different positions in the air-cleaner system. Caterpillar describes its secondary element as providing protection during primary-element changes or a breach of the primary element. This supporting role is not a reason to order it as a substitute for the primary element. Source: Caterpillar Parts Store, 110-6326 and 110-6331 descriptions.
| Reference | Manufacturer catalogue role | What to specify on the order |
|---|---|---|
| 110-6326 | Primary element | Quantity and matching air-cleaner application. |
| 110-6331 | Secondary element | Quantity, individual identification and whether supplied with the primary. |
These catalogue descriptions identify the reference roles. They do not establish the filtration performance or manufacturing origin of a separately supplied replacement.
Which ends should be photographed?
Send the open or sealing end, the closed end and the full side profile of each old element. Add photographs of the air-cleaner housing identification and both element labels. This separates a housing match from a visual resemblance between cylindrical filters.
If measurements are needed, state overall length, outside diameter and the relevant opening diameter in millimetres, with the measuring points identified. Do not estimate a sealing diameter from a perspective image. Include any differences in end-cap shape instead of assuming they are cosmetic.
How do you make a two-element quotation clear?
Write one line for 110-6326 and a second for 110-6331, then state whether you need one paired set or multiple sets. Ask the supplier to confirm the contents of each package and provide readable markings for both elements. A photograph containing two filters is not itself a packing list.
Also supply the machine and engine identification and the air-cleaner housing reference where available. For replacement intervals and handling procedures, use the service information for that equipment; a sales listing does not set the maintenance schedule.
Reference roles and product photographs reviewed on 19 September 2026. No filtration test or field-service outcome is claimed.
Published by GUANGZHOU JIAJUE MACHINERY EQUIPMENT CO.,LTD. Send your parts inquiry with the machine identification, required quantity and delivery destination.
