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Recipe - Duramax 6.6L V8 Turbo Diesel (GM HD, LB7-LMM 2001-2010)

Specific Fix build

Reliability tier: aggregated - verify before ordering, see /disclosure/

CP3 and fuel-system contamination service (CP3 pump / fuel system contamination): the Bosch CP3 is fed by the OEM filter setup, and water/debris are the standing threats. Refresh path: filter service (head assembly per generation + element kit + WIF sensor), the CP3 pressure-relief valve when rail pressure sags, and the pump itself (OEM reman or BD Stock Exchange as the Dave's option) when it fails. The 2001-2010 platform has no in-tank OEM pump - the lift-pump upgrade is the contamination-protection layer.

Parts

• Duramax LB7 Fuel Filter Head Assembly (OEM) - the LB7 filter head assembly - the aluminum head commonly thread/freeze-cracks at the heater port (qty 1)
• Duramax LLY+ Fuel Filter Assembly (OEM) - the later (2004-2010) filter assembly line (qty 1)
• Duramax Fuel Filter Heater (OEM) - heater element in the head - cold-weather gelling protection (qty 1)
• Duramax Fuel Filter Service Kit (OEM) - element service kit, all generations (qty 1)
• Duramax Water-In-Fuel Indicator Sensor (OEM) - water-in-fuel sensor - the early warning that protects everything downstream (qty 1)
• Duramax CP3 Fuel Pressure Service Valve (OEM) - CP3 rail-pressure relief valve - the wear item behind sagging rail pressure (LLY window) (qty 1)
• Duramax LB7 CP3 Injection Pump (Reman OEM) - OEM reman CP3 for LB7; Dave's option is the BD Stock Exchange pump (qty 1)
• Duramax LLY CP3 Injection Pump (Reman OEM) - OEM reman CP3 for LLY; BD Stock Exchange as Dave's option (qty 1)
• Duramax LBZ/LMM CP3 Injection Pump (Reman OEM) - OEM reman CP3 for LBZ/LMM; BD Stock Exchange as Dave's option (qty 1)
• Duramax CP3 Fuel Injection Pump Seal (OEM) - CP3 rear seal/O-ring, all generations (qty 1)
• Duramax 2001-2010 Lift Pump Upgrade (FASS Titanium Signature C10 100G) - the protection layer: electric lift pump + filtration for the whole window (qty 1)

Install order

1. water-in-fuel check and full filter service
2. gauge rail pressure; test the relief valve before condemning the pump
3. replace pump/seals per findings (verify generation at the 2004/2007 switches)
4. fit lift pump as the standing protection upgrade

Expected outcome

stable rail pressure across the rev range; clean WIF readings; no air-in-fuel symptoms

Do not

• do not run a CP3 dry after filter service - prime the system first
• do not ignore WIF warnings - water kills the pump and the injectors it feeds
• do not replace the pump before the relief valve is cleared - the valve mimics pump failure

Parts budget

About $10-$890 in parts. It depends on what the diagnosis finds; each option below is what you buy together. Prices marked "at Dave's" are Dave's Auto Center's, the same as in his store; the others are approximate prices from OEM and maker catalogs, rounded (a manufacturer's list price can run higher). Parts only, no labor.

• about $610: Duramax LB7 Fuel Filter Head Assembly (OEM) (about $610)
• about $160: Duramax LLY+ Fuel Filter Assembly (OEM) (about $160)
• about $170: Duramax Fuel Filter Heater (OEM) (about $170)
• about $65: Duramax Fuel Filter Service Kit (OEM) (about $65)
• about $40: Duramax Water-In-Fuel Indicator Sensor (OEM) (about $40)
• about $270: Duramax CP3 Fuel Pressure Service Valve (OEM) (about $270)
• $883.95: Duramax LB7 CP3 Injection Pump (Reman OEM) ($883.95 at Dave's)
• $883.95: Duramax LLY CP3 Injection Pump (Reman OEM) ($883.95 at Dave's)
• $840.95: Duramax LBZ/LMM CP3 Injection Pump (Reman OEM) ($840.95 at Dave's)
• about $10: Duramax CP3 Fuel Injection Pump Seal (OEM) (about $10)
• $714.00-$853.95: Duramax 2001-2010 Lift Pump Upgrade (FASS Titanium Signature C10 100G) ($714.00 at Dave's)

DIY or shop: Mixed: filter/sensor service is DIY-capable; CP3 replacement is shop work (injection-pump timing).