Product Description
MAHLE K31904 is an OE-quality molded-rubber water pump seal (O-ring) for the 2001–2016 GM 6.6L Duramax. It seals the back of the water pump to the front cover to prevent coolant leaks and restore reliable cooling performance.
- Direct-fit replacement for LB7/LLY/LBZ/LMM/LML 6.6L Duramax engines
- Meets or exceeds OE specifications
- Material: Molded rubber • Seal type: O-ring
- GTIN/UPC: 027067720979
Fitment
- 2001–2004 LB7 6.6L Duramax
- 2004.5–2005 LLY 6.6L Duramax
- 2006–2007 LBZ 6.6L Duramax
- 2007.5–2010 LMM 6.6L Duramax
- 2011–2016 LML 6.6L Duramax
- Common applications include Chevrolet Silverado/GMC Sierra 2500HD/3500HD; also used on select Express/Savana vans.
Cross Reference Numbers
- GM / ACDelco: 94013304
- Fel-Pro: 35756
- MAHLE: K31904
What’s Included
(1) Water pump mounting seal (O-ring).
FAQ
Will this fit my 6.6L Duramax?
Yes—this seal fits 2001–2016 6.6L Duramax engines (LB7, LLY, LBZ, LMM, LML). Always verify by engine code and build date.
Where does this seal install?
It installs between the rear of the water pump and the front cover to prevent coolant leaks.
Do I need additional gaskets?
If you’re servicing the pump, consider a full gasket kit for related seals (see recommended product below).
Torque or sealant required?
Follow GM service manual torque specs. No additional sealant is typically required on this O-ring.
