Shopping for: Confirm the part against your engine serial number and application before ordering.
Change engine
121254 O-RING (Pack of 6)
Commercial diesel seals / o-rings. Match the listed part and engine identifiers before ordering.
2-Year WarrantyPAI Industries
$17.94
In stock — ships same day
88 available
PAI Part #121254
JAK'S Part #JAKS-121254
Kit Membership
Used In These Kits
This part is included in 12 engine & overhaul kits — find yours below.
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121371O-RING KIT In stock -
131271UPPER GASKET KIT In stock -
131272-200Cummins N14 O-Ring Sub Kit In stock -
131482-154Cummins OIL GASKET KIT In stock -
131561UPPER GASKET KIT In stock -
131684Cummins QSC ENGINES UPPER GASKET SET In stock - 131685LOWER GASKET KIT View ›
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131809Cummins Upper Gasket Kit In stock -
131886UPPER GASKET KIT In stock -
131891UPPER GASKET KIT In stock -
131892UPPER GASKET KIT In stock -
940289RANGE KIT In stock - No kits match that search.
Complete The Rebuild
Suggested Additional Parts
Commonly sold with this product. These parts are sold separately.
| Brand | PAI Industries |
| Part Category | Gaskets & Seals |
| Sub-Type | O-Ring |
Sold in a pack of 6. Price shown is for 6 pieces.
O-RING
OEM cross-references:
- CATERPILLAR 033-5879
- CUMMINS 3001340
- CUMMINS 4076420
- MACK 1577-3001340
- CUMMINS 3867043
- CUMMINS 3882589
- CATERPILLAR 335879
- MACK 56AX604
- CUMMINS 4989614
- CUMMINS 3943857
- ROCKWELL (EXCEL PRODUCTS) 5X1207
- MACK 8235-5X1207
Warranty: 24 months
Most PAI parts carry a 2-year unlimited-mileage PAI warranty — 3 years on the High Performance tier, 1 year on Excel by PAI. See Warranty & Returns for full coverage terms, or call a specialist to confirm the exact coverage on this part.
PAI published warranty tiers: High Performance — 3-Year · Genuine PAI — 2-Year · Excel — 1-Year, unlimited mileage. The badge beside the price shows this product's recorded term; when no badge is shown, confirm coverage with a specialist.
















