The Bostech ISK627 Fuel Pressure Regulator Master Rebuild Kit is a comprehensive service overhaul kit engineered specifically for the engine-mounted secondary fuel filter bowl and pressure regulator on 2003–2007 Ford 6.0L Powerstroke diesel engines. Featuring precision-molded, high-temperature fluorocarbon (Viton) elastomeric seals and internal regulator components, this master kit reseals every internal and external fluid passage on the fuel filter canister to restore positive fuel containment, maintain regulated pressure, and eliminate fuel pooling in the engine valley.

Quick Specs & Kit Inclusions

• Application: Engine valley mounted secondary fuel filter canister and fuel pressure regulator complete reseal
• Seal Material: High-grade, fuel-resistant fluorocarbon (Viton) formulated to resist ultra-low sulfur diesel (ULSD) and biodiesel degradation
• Coverage: Master canister kit (services regulator housing face, internal valve stem, and fuel bowl ports)
• Emissions Status: 50-state legal (direct mechanical replacement)
• Direct Interchange Part Numbers: Ford 3C3Z-9C165-AA, Alliant AP0014
• What's in the Box: (1) Molded Regulator Housing Perimeter Gasket, (1) Internal Regulator Valve Plunger Grommet, (4) Internal Port/Passage O-Rings, (1) Return Passage Grommet, and (4) T27 Torx Cover Screws

Problem Solved: Curing Engine Valley Puddles & Fuel Pressure Bleed-Off

A frequent failure point on 6.0L Powerstroke engines is fuel weeping from the secondary fuel filter bowl assembly mounted in the engine valley. Over thousands of heat cycles, factory elastomer seals harden, flatten, and crack under constant low-pressure fuel circulation. Diesel fuel pools in the engine valley, creating severe underhood fuel fumes, dissolving underlying engine harness loom, and softening coolant hoses below. Internally, fatigued regulator grommets allow pressurized fuel to bleed across return circuits, causing loss of supply pressure to the fuel injectors, extended crank times, and hard-start conditions due to fuel drain-back. The Bostech ISK627 master kit replaces every sealing point across the secondary fuel canister to ensure factory-tight hydraulic boundaries without replacing the entire fuel bowl assembly.

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 & MaxxForce 5 Engines

Safety & Depressurization: Park the vehicle on level ground, turn off the ignition, and disconnect both negative battery cables. Slowly loosen the secondary fuel filter cap (24mm or 15/16" socket) on top of the engine valley bowl to vent residual head pressure and allow fuel to drain down. Access & Removal: Place absorbent shop towels beneath the regulator housing on the side of the secondary fuel filter bowl. Using a T27 Torx driver, remove the retaining screws securing the regulator cover. Maintain firm pressure against the cover while loosening the final screw to prevent internal spring tension from kicking the cover loose. Canister Cleaning & Inspection: Remove the regulator cover, spring, brass valve plunger, and old seals. Extract all old internal port O-rings and stem grommets from the canister using a non-marring brass or plastic pick. Suction standing fuel and particulate debris from the reservoir; wipe mating faces clean with lint-free towels and brake cleaner. Seal Lubrication & Placement: Lightly coat all new Bostech Viton O-rings, passage seals, and grommets with clean diesel fuel or motor oil. Press the replacement internal valve grommet squarely into its seat inside the housing bore. Fit the new molded perimeter face gasket into the machined channel of the regulator cover, verifying it lies completely flat without stretching or twisting. Reassembly: Reinstall the brass regulator piston and spring into the housing cavity. Hold the regulator cover square and flush against the fuel bowl body, compressing the spring by hand to ensure the perimeter seal remains locked in its groove and does not pinch. Torque Target: Hand-thread the included T27 Torx screws to ensure clean thread engagement. Tighten the screws evenly in an alternating, crisscross pattern to 45–55 in-lbs (5–6 Nm) using a 1/4-inch drive torque wrench. Do not over-torque, as the aluminum fuel bowl threads strip easily. Filter Cap Torquing: Verify the secondary fuel filter cap O-ring is properly positioned and lubricated, then torque the cap to 19 ft-lbs (25 Nm). Priming & Leak Verification: Reconnect both negative battery cables. Turn the ignition key to the "RUN" position for 30 seconds without cranking to allow the electric lift pump to fill the bowl, pressurize the system, and bleed trapped air. Repeat this key cycle 4 to 5 times. Check the entire regulator seam, canister ports, and valley area for zero leaks before starting the engine.