2017-2019 Ford 6.7L Powerstroke Fuel Lines

Fuel Lines on the 2017-2019 Ford 6.7L Powerstroke

The fuel system on these trucks splits into two pressure zones. The low-pressure side starts at the electric lift pump in the frame-mounted Diesel Fuel Conditioning Module and runs through the primary and secondary filters. The high-pressure side starts at the Bosch CP4.2, which feeds twin rails at up to roughly 30,000 psi, and the injection lines carry that fuel from the rails to eight 19 mm piezo injectors. The stock-style kits here pair the injection lines with fresh O-rings, and the rail supply line between the pump and the rails is sold as its own part.

What fails and why

The big threat to the lines on this platform is not the lines themselves; it is the CP4.2. When the pump's internal cam follower loses contact with the cam lobe on low-lubricity ULSD, it wears and sheds metal into the rails, injectors and lines. That is why a CP4.2 failure is rarely a pump-only repair: the fix replaces both pumps, all eight injectors and every fuel line, along with the rails, and includes removing and cleaning the tank. Leaks are the other line problem worth knowing. A hard start when the engine is warm most often traces to a fuel-system leak that lets the system lose prime, or to poor fuel, so check for leaks and look at the filters before you condemn the pump.

Stock replacement vs. upgrade

For a stock truck, stay with stock-style parts: the Alliant Power injection line and O-ring kits, the BD Diesel injector line set and the MAHLE rail supply line all replace factory pieces. After a pump failure, a fuel contamination kit, offered with or without the pump, is built for that job; check the listing for exactly what is included. The upgrade side of this collection is about plumbing for builds. High-power 6.7L builds run into the CP4.2's limit, because it cannot hold rail pressure at long injector durations, so they add a second pump. That is where universal oversized high-pressure lines and AN supply fittings come in.

What we carry

Alliant Power supplies the AP0087 and AP0088 injection line and O-ring kits, the AP57002 fuel contamination kit and its AP57002NP no-pump version, plus ULTRAGUARD, LUBRIGUARD and WINTERGUARD diesel fuel treatments. XDP offers the XD516 contamination kit and the XD613 no-pump kit, and SPE Motorsport has the DKT171967 fuel contamination kit. MAHLE makes the GS33712 fuel rail supply line, and BD Diesel makes the 1050165 fuel injector line set. For custom plumbing, Dynomite Diesel sells universal oversized high-pressure injection lines in multiple lengths, and Exergy Performance carries an M14x1.5 three-way T fitting, an M14x1.5 plug and nut rail cap, and M12x1.5 to -6AN and -8AN high-flow CP3 supply fittings.

Fitment notes

Read the year range in each title. The Alliant line kits and the MAHLE supply line are listed for 2011-2019, the BD line set for 2011-2021, and the contamination kits are specific to 2017-2019. Do not assume 2020-and-later parts carry back: those trucks run 36,000 psi rails with a different calibration and hardware set. The Exergy fittings are listed by thread size and the Dynomite lines are universal, so match sizes and lengths to your build. If your build pairs these fittings with a CP3-based pump, confirm that kit's model-year fitment and CARB EO status for your state. Chassis cab F-350, F-450 and F-550 trucks differ from pickups in many parts. Verify by VIN when in doubt.

Frequently asked questions

Do I need new fuel lines after a CP4.2 failure?

Yes. When a CP4.2 fails it sends metal into the rails, injectors and lines, and the repair replaces the high-pressure lines along with the rails and all eight injectors. The Alliant and XDP contamination kits, or the SPE kit, are built around that job.

What is the difference between a contamination kit with the pump and the no-pump version?

The no-pump kits, Alliant AP57002NP and XDP XD613, leave out the injection pump, so you can source the pump separately, such as a new or reman CP4. The full kits, AP57002 and XD516, include it. Either way, the rest of the contaminated system still has to be replaced.

Can a fuel leak cause hard starting on my 6.7L?

It can. A long crank when the engine is warm most often traces to a fuel-system leak that lets the system lose prime, or to poor fuel. Check the lines, fittings and filters before you condemn the CP4.2.

Will lines from a 2020 or newer Super Duty fit my 2018?

Do not count on it. The 2020 refresh raised rail pressure to 36,000 psi with a different calibration and hardware set, while 2017-2019 trucks run up to roughly 30,000 psi. Buy parts listed for your model year, like the 2011-2019 Alliant line kits.

Not sure what fits? Call the shop at the number in the header, or use the fitment checker on any product page. We install everything we sell.