Upgrading to a braided fuel feed line offers improved durability, resistance to abrasion, and a cleaner aesthetic compared to factory rubber hoses. This guide outlines the process of assembling a custom braided line that integrates with your vehicle's existing OEM banjo fitting, ensuring proper fuel delivery to the engine.

Important

Working with fuel systems carries inherent risks. Ensure proper ventilation, have a fire extinguisher readily available, and wear appropriate personal protective equipment (PPE) including eye protection and chemical-resistant gloves. Depressurize the fuel system completely before beginning any work.

Required Components and Tools#

Successful assembly requires specific tools and high-quality components designed for fuel system use. Ensure all AN fittings and hose are compatible with gasoline or ethanol-blended fuels.

Components#

• Braided Fuel Hose: PTFE (Teflon) lined hose is recommended for its superior chemical resistance and durability compared to rubber-lined options. Select the appropriate AN size (e.g., -6AN or -8AN) for your application.
• AN Hose Ends: Straight, 45-degree, 90-degree, or 120-degree swivel hose ends as needed for routing. Ensure they match your chosen AN hose size.
• OEM Banjo to AN Adapter: A specific adapter that converts the outlet of your OEM banjo fitting (typically on the fuel rail or fuel filter) to a male AN fitting (e.g., -6AN or -8AN). Confirm the correct thread pitch and size for your specific vehicle's OEM banjo.
• Crush Washers/Seals: New crush washers or O-rings for the OEM banjo bolt and adapter, as specified by the manufacturer.

Tools#

• AN Wrench Set: Aluminum AN wrenches prevent marring the finish of AN fittings.
• Hose Cutter: A specialized braided hose cutter or a sharp cut-off wheel for clean, fray-free cuts.
• Vise with Soft Jaws: Essential for securely holding fittings during assembly without damage.
• Thread Sealant/Lubricant: AN assembly lube or a compatible thread sealant for proper fitting assembly.
• Torque Wrench: For tightening the banjo bolt and AN fittings to factory specifications.
• Drain Pan: For collecting residual fuel.
• Shop Rags: For cleanup.

Preparation and Safety#

Prioritize safety before starting any work on the fuel system.

1. Disconnect Battery: Disconnect the negative terminal of the vehicle's battery to prevent accidental electrical shorts.
2. Depressurize Fuel System: Consult your factory service manual (FSM) for the exact procedure to depressurize the fuel system. This typically involves removing the fuel pump fuse/relay and cranking the engine until it stalls, or using a fuel pressure gauge with a bleed-off valve.
3. Ventilation: Work in a well-ventilated area to disperse fuel vapors.
4. Fire Extinguisher: Keep a suitable fire extinguisher (Class B or ABC) within arm's reach.

Assembly Procedure#

1. Remove Existing Fuel Line#

• Place a drain pan beneath the fuel line connections. Slowly loosen the factory fuel line connections at the fuel rail and the fuel filter/hard line. Expect some residual fuel to leak out.
• Carefully remove the old fuel feed line, noting its routing for the new braided line.

2. Prepare Braided Hose#

• Measure the desired length for your new braided fuel line, accounting for the length added by the AN fittings and any bends. It's often helpful to mock up the routing with the old line or a piece of string.
• Using a specialized hose cutter or a cut-off wheel, make a clean, square cut through the braided hose. Wrap the cut area with electrical tape before cutting to minimize fraying if using a saw.
• Clean the inside of the hose to remove any debris from cutting.

3. Assemble AN Hose Ends#

Tip

Practice assembling AN fittings on a scrap piece of hose if you are new to the process. Proper assembly is critical for leak-free operation.

• Disassemble the Fitting: Separate the AN hose end into its two main components: the socket and the nipple/olive.
• Install the Socket: Thread the hose counter-clockwise into the socket until the hose bottoms out against the internal stop. Ensure the hose braiding does not unravel.
• Lubricate: Apply AN assembly lube or a compatible lubricant to the threads of the nipple and the inside of the hose.
• Assemble Nipple: Carefully thread the nipple into the socket, ensuring the hose does not push out of the socket. Tighten by hand until snug, then use AN wrenches to tighten until a small gap (typically 1/32" to 1/16") remains between the socket and the nipple hex. Do not overtighten, as this can damage the fitting or hose.
• Repeat for the other end of the hose.

4. Install OEM Banjo to AN Adapter#

• Identify the OEM banjo fitting on your fuel rail or fuel filter. Remove the original hose or fitting connected to its outlet.
• Install the new OEM banjo to AN adapter onto the OEM banjo fitting. Use new crush washers or seals as specified by the adapter manufacturer or the FSM.
• Tighten the adapter to the specified torque value. Confirm the correct torque specification for your specific vehicle's banjo bolt and adapter with the factory service manual.

5. Install the Braided Fuel Line#

• Carefully route the assembled braided fuel line, ensuring it does not rub against any sharp edges, hot components, or moving parts. Use appropriate clamps or stand-offs to secure the line.
• Connect one end of the braided line to the newly installed OEM banjo to AN adapter. Tighten the AN fitting using AN wrenches. Do not overtighten.
• Connect the other end of the braided line to its destination (e.g., fuel filter, hard line). Tighten this AN fitting as well.

Post-Installation Verification#

After installing the new fuel line, perform a thorough check for leaks before operating the vehicle.

1. Reconnect Battery: Reconnect the negative battery terminal.
2. Prime Fuel System: Turn the ignition key to the ON position (without starting the engine) for a few seconds, then turn it OFF. Repeat this process several times to allow the fuel pump to prime the system and build pressure. Listen for the fuel pump cycling.
3. Inspect for Leaks: Carefully inspect all connections for any signs of fuel leakage. Use a flashlight and look for drips or wet spots. Address any leaks immediately by re-tightening connections slightly or disassembling and reassembling if necessary.
4. Start Engine: Once you are confident there are no leaks, start the engine and let it idle. Continue to monitor all fuel line connections for leaks while the engine is running.
5. Test Drive: After confirming no leaks at idle, perform a short test drive, then re-inspect the connections.

Caution

Any fuel leaks, no matter how small, must be resolved immediately. Do not operate the vehicle with a leaking fuel system.

Maintenance#

Regularly inspect your braided fuel line for signs of wear, abrasion, or damage. Ensure all fittings remain tight and secure. While braided lines are durable, they are not maintenance-free.