The Mahle Original GS33442 Fuel Injector Seal Master Set is a complete, full-engine OEM-grade replacement reseal kit engineered specifically for 2003–2010 Ford Super Duty trucks, Excursions, and E-Series vans equipped with the 6.0L Powerstroke diesel engine (as well as Navistar VT365 applications). Unlike single-cylinder service packs, the GS33442 master set includes all external body O-rings and solid copper combustion washers required to completely service all eight (8) G2.8 HEUI fuel injectors in one box. Manufactured by Mahle—an original equipment supplier to Navistar and Ford—these seals restore positive fluid separation across the 55–65 PSI fuel rails, engine oil passages, and combustion chambers.

Quick Specs & Kit Inclusions

• Application: Complete engine (all 8 cylinders) external HEUI fuel injector reseal and combustion washer pack
• Elastomer Grade: Premium fluorocarbon (FKM / Viton) engineered to withstand continuous engine oil temperatures exceeding 250°F and resist diesel/biodiesel fuel swelling
• Combustion Washers: Precision-stamped, annealed solid copper crush washers designed to deform evenly under factory hold-down clamp torque
• Engine Coverage: Services all eight (8) fuel injectors (1 complete V8 engine)
• Emissions Status: 50-state legal (direct mechanical replacement sealing components)
• Direct Interchange Part Numbers: Mahle GS33442, Victor Reinz GS33442; services equivalents to Ford 3C3Z-9229-AA (x8), Motorcraft CM-5055 (x8), Alliant Power AP0002 (x8), DTech DT600015 (x8)
• What's in the Box:
  • (8) Upper External Body O-Rings
  • (8) Lower Fuel Rail Body O-Rings
  • (8) Intermediate Support/Sealing Rings
  • (8) Solid Copper Combustion Tip Crush Washers
  • (Packaged in Mahle's protective shrink-wrapped inspection tray)

Problem Solved: Curing Engine Oil Fuel Dilution, Combustion Blow-By & Aeration

Whenever injectors are removed on the 6.0L Powerstroke—during head stud installations, injector upgrades, or rocker carrier repairs—the factory elastomer O-rings and copper tip washers take a permanent heat and compression set. Attempting to reinstall used seals leads to critical engine issues:

• Lower Body O-Ring Failure: Allows pressurized diesel fuel from the cylinder head rail to migrate past the injector body directly into the engine crankcase, diluting motor oil, raising oil levels, thinning viscosity, and destroying rod and main bearings.
• Combustion Washer Degradation: High-pressure combustion soot blows past the nozzle seat, scorching the lower body O-ring, carbon-fouling the fuel supply rail, aerating the fuel system, and eroding the brass cylinder head sleeve.
• Upper Sealing Ring Breakdown: Permits oil and fuel cross-contamination around the rocker carrier area.

Installing the Mahle GS33442 master set provides factory-blueprint sealing elasticity across all 8 cylinders simultaneously, eliminating the need to purchase multiple single-injector packs.

Fitment

• 2003–2007 Ford F-250 Super Duty 6.0L Powerstroke Turbo Diesel
• 2003–2007 Ford F-350 Super Duty 6.0L Powerstroke Turbo Diesel
• 2003–2007 Ford F-450 Super Duty 6.0L Powerstroke Turbo Diesel
• 2003–2007 Ford F-550 Super Duty 6.0L Powerstroke Turbo Diesel
• 2003–2005 Ford Excursion 6.0L Powerstroke Turbo Diesel
• 2004–2010 Ford E-Series Vans (E-350 / E-450) 6.0L Powerstroke Turbo Diesel
• 2004–2008 Ford F-650 / F-750 Super Duty (VT365 Engine)
• 2003–2007 International / Navistar VT365 Engines

Safety & Workspace Teardown: Turn off the ignition and disconnect both negative battery cables. Remove intake ducting, intercooler (CAC) piping, valve covers, and both driver- and passenger-side high-pressure oil rails to access all 8 fuel injectors. Injector Extraction & Old Seal Removal: Unbolt the hold-down clamps, disconnect the FICM electrical connectors, and carefully remove the injectors. Using a brass or plastic pick, remove the old external body O-rings. Remove the copper washers from each nozzle tip (verify that no old copper crush washers remain stuck in the bottom of the cylinder head cups). Groove & Nozzle Cleaning: Clean the injector body O-ring grooves and nozzle exteriors with lint-free towels and brake cleaner to remove dried carbon deposits, oil varnish, and grit. Injector Cup Inspection: Thoroughly clean each brass cylinder head cup using a dedicated 6.0L bore brush and vacuum. The bottom copper seating face must be 100% clean, dry, and bare metal to guarantee a leak-free combustion seal. New Seal Installation: Lightly coat the new Mahle Viton body O-rings with clean engine oil (15W-40 or 5W-40). Roll the body O-rings into their designated upper and lower grooves on each injector. Ensure the rings sit flat without twists or spirals. Slide the new solid copper crush washers onto each nozzle tip, using a tiny dab of clean grease to hold them securely during insertion. Injector Installation & Alignment: Align each injector squarely with its cylinder head dowels. Slide each injector straight down into its cup by hand and apply firm downward pressure on the injector shoulder until it seats fully. Hold-Down Torquing: Position the hold-down clamps and hand-thread the fasteners into the cylinder head. Torque bolts to factory specification: T40 Torx Bolts (18mm Dowel Heads): 24 ft-lbs (33 Nm) T45 Torx Bolts (20mm Dowel Heads): 26 ft-lbs (35 Nm) Final Assembly & Fuel Priming: Reinstall the high-pressure oil rails (torque rail bolts to 10 ft-lbs / 13 Nm), connect all FICM injector harness plugs until the wire bails snap securely, and reinstall the valve covers. Reconnect battery terminals, cycle the ignition key (KOEO) 4 to 5 times for 30 seconds each to purge air from the fuel rails, then start the engine and verify smooth, smoke-free idle.