How to Make AN Fuel Lines with Nylon Braided Hose: A Step-by-Step Guide

Introduction

If you're upgrading your fuel system, making custom AN fuel lines with nylon braided hose is a great way to ensure a clean and professional setup.

I’ll cover the tools you need, the step-by-step process, and some tips to make the job easier. Let’s get started!

Tools and Materials Needed

Before you begin, gather these tools:

AN Fittings
Nylon Braided Fuel Hose
Angle Grinder with Cut-Off Wheel (or alternative cutting tools)
Soft Jaws or Wood Blocks (to protect fittings in a vise)
Crescent Wrenches (or specialty aluminum wrenches for AN fittings)
Tape (Electrical or Masking Tape) (to prevent fraying and for marking cuts)
Lubricant (Oil or Assembly Lube) (for threading fittings)
Compressed Air (for cleaning the hose after cutting)
Sharp Blade or Scissors (for trimming stray strands)

Step 1: Measure and Mark the Hose

Determine the hose length needed to connect your components (e.g., fuel rail to gas tank).
Wrap electrical tape around the hose where you plan to cut. This prevents the braided hose from fraying when cut.
Use a marker on the tape to make accurate measurement marks.

Step 2: Cut the Hose

There are multiple ways to cut braided hose, including:

Angle Grinder with a Cut-Off Wheel (produces clean cuts)
Sharp Blade or Scissors (requires careful precision)
PVC Cutters (some people use these, but they may not work well for braided hoses)

Cutting Tips:

Hold the hose firmly and make a smooth, single pass through the cut.
Avoid excessive pressure, which can crush the hose and make fitting installation harder.
Immediately after cutting, blow compressed air through the hose to remove any debris.
If you notice any loose strands, use a sharp blade or scissors to trim them.

Step 3: Preparing the AN Fitting

Disassemble the AN fitting – it comes in two pieces:
- The socket (the larger piece that the hose inserts into)
- The nipple (the smaller piece that threads into the hose end)
Inspect the inside of the socket to locate the back edge where the hose will bottom out.

Step 4: Insert the Hose into the Fitting

Start by gently twisting the hose into the fitting socket while applying light pressure.
Continue turning and pushing until the hose bottoms out against the back of the socket.
Visually check that the hose is sitting flush with the back of the fitting.

Step 5: Assemble the AN Fitting

Apply a small amount of lubricant (oil or assembly lube) to the fitting threads.
Start threading the nipple piece by hand to avoid cross-threading.
Once it becomes too tight to turn by hand, move to the vise.

Step 6: Tighten the Fitting in a Vise

Secure the soft jaws or taped wooden blocks in the vise to protect the fitting.
Place the fitting into the vise and use wrenches to fully tighten it.
Ensure there are no visible gaps between the two fitting pieces.

Step 7: Final Inspection

Check for gaps between the fitting pieces – if there are any, tighten further.
Ensure the hose is not crushed or deformed from the assembly.
Blow compressed air through the hose one last time to remove any internal debris.

Conclusion

That’s it! Your AN fuel line is now ready to connect to your fuel system. By following these steps, you ensure a clean, leak-free installation. If you plan on making multiple AN lines, investing in aluminum wrenches and soft jaws will make the process even smoother.