Product Description
MAHLE K31904 is an OE-quality molded-rubber water pump seal (O-ring) that installs between the rear of the water pump and the front cover on 6.6L Duramax engines. Direct-fit for 2001–2016 LB7/LLY/LBZ/LMM/LML.
- Direct replacement; meets or exceeds OE specifications
- Seal type: O-ring • Material: molded rubber
- GTIN/UPC: 027067720979
Fitment
- 2001–2016 Chevrolet Silverado / GMC Sierra 2500HD, 3500HD (LB7, LLY, LBZ, LMM, LML)
- 2006–2015 Chevrolet Express / GMC Savana 2500, 3500; 2009–2014 Express/Savana 4500
- 2003–2006 Chevrolet Kodiak / GMC TopKick C4500, C5500
Cross Reference Numbers
- GM / ACDelco: 94013304
- Fel-Pro: 35756
- MAHLE: K31904
What’s Included
(1) water pump mounting seal (O-ring).
Installation Notes
Replace this O-ring any time the water pump is removed. Clean mating surfaces, lightly lubricate with coolant, and torque per GM service manual.
FAQ
Will this fit my Duramax?
Yes — it fits 2001–2016 6.6L Duramax LB7, LLY, LBZ, LMM, and LML.
Where does this seal install?
Between the back of the water pump and the front cover to seal the pump mounting surface.
Do I need sealant?
No additional sealant is typically required on this O-ring; follow GM torque and assembly procedures.
