| Subject: | Information on a Revised Fuel Filter for 6.6L LLY and LB7 Duramax™ Diesel Engine |
| Models: | 2001-2004 Chevrolet and GMC C/K Models with 6.6L Engine (VIN 1 - RPO LB7) |
| 2003-2004 Chevrolet and GMC C4500/C5500 Series Models with 6.6L Engine (VIN 1 - RPO LB7) |
| 2004-2006 Chevrolet and GMC C/K Models with 6.6L Engine (VIN 2 - RPO LLY) |
| 2004-2006 Chevrolet and GMC C4500/C5500 Series Models with 6.6L Engine (VIN 2 - RPO LLY) |
| 2006 Chevrolet and GMC Express/Savana Models with 6.6L Engine (VIN 2 - RPO LLY) |
This bulletin is being revised to provide additional information to the field on fuel filter applications on the Duramax™ diesel engine. Please discard Corporate Bulletin Number 04-06-04-070 (Section 06 - Engine/Propulsion System).
A revised fuel filter is planned for release that will service all 2001-2006 vehicles with the 6.6L Duramax™ Diesel. The new filter is slightly longer than the current filter and has a stepped shape at the bottom. The length of the new filter will
not change the recommended fuel filter change interval of 24,000 km (15,000 mi) for C/K and C4500/C5500 models, and 32,000 km (20,000 mi) for Express/Savana models.
Proper fuel filter servicing and the use of clean diesel fuel that is free of water or contaminants are critical for the longevity of fuel system components of a modern direct injected diesel engine. Adherence to the fuel filter change interval will help
to ensure that the Duramax fuel system will be protected from contaminants and that the engine will continue to operate as designed. Purchasing fuel from a high volume fuel retailer increases the chances that the fuel is fresh and of good quality.
