How to Install AN PTFE Hose and Fittings

Whether you're a hobbyist upgrading your fuel lines or a pro working on EFI conversions, LS swaps, or custom AN plumbing, this guide will walk you through the installation of AN PTFE hose ends with precision and reliability. Our step-by-step tutorial ensures a leak-free result for fuel systems, transmission lines, and more.

 

Step 1: Measure twice and cut once AN PTFE Hose

Use String or lay the hose out to get an accurate measurement for your project. We advise leaving a few extra inches to account for slight changes to the layout of your AN hose project. Be sure to account for the correct  bend radius  of your hose.








Step 2: Cut Your AN PTFE Hose

Use AN Hose Cutting Shears for a clean, straight cut. Wrap the hose with a single wrap of masking tape before cutting to prevent fraying.

 

 

 

 

 

 

 

 

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Step 3: Slide On the Nut

Slide the nut over the end of the hose with the threads facing forward. We recommend using vice jaws to assist with getting the nut over the nylon braiding. Place the nut into the vice jaws and twist the hose into the nut treating it as though it's threaded. 

PTFE hose fitting in aluminum vice jaw during installation

Buy Aluminum Vice jaw for PTFE Hose Ends

Step 4: Flare the Braid and Insert the Ferrule

Carefully flare the stainless braid and insert the ferrule over the PTFE liner, under the braid. Trim the nylon if needed to make tightening the PTFE hose fittings easier and prevent the aluminum fitting threads from becoming damaged.

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Step 5: Insert the Fitting

Lubricate the barb and insert the fitting into the hose. Ensure it seats completely into the ferrule.

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Step 6: Tighten the Assembly

Thread the nut onto the fitting by hand. Use a proper AN wrench and vice jaws to finish tightening until a 1mm gap remains.

Get Adjustable AN Wrench Shop Vice Jaws Tightening AN fitting

Step 7: Test for Leaks

Cap one end and pressure test the hose. Use soapy water or submerge it to check for leaks. Using an air compressor with an AN adapter and a pressure gauge is an excellent way to ensure that the assembly will maintain pressure. If submersing the hose or using soapy water be aware that bubbles will escape from the fitting pin that holds the swivel portion on and are not signs of a leak. 

pressure testing AN PTFE hose assembly

 

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Tips for Easier Assembly

  • Always use light lubricant on fittings before insertion.
  • Use tape generously to keep braid from flaring.
  • Use proper tools like hose shears and vice jaws to avoid damaging the hose or fittings.
  • Replace ferrules when reusing fittings.
  • Inspect and pressure test every line after assembly.

Need Help or Want a Custom Build?

Have questions or want us to help with a complete fuel or transmission line system? We’re here to help!

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Looking for a tailored solution for your build? Use our Build Request Form to get a custom hose and fitting layout made just for your EFI system, LS swap, carbureted build, or custom AN plumbing project.

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