GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1997 🢒 GMC K Pickup - 4WD 🢒 Engine 🢒 Engine Controls - 4.3L 🢒 Fuel Hose and Pipes

Fuel Hose and Pipes Engine Fuel Pipes

Removal Procedure

    Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

  1. Disconnect the negative battery cable.
  2. Relieve the fuel system pressure. Refer to the Fuel Pressure Relief Procedure .

    3. Object Number: 18332 Size: SH
  3. Disconnect the fuel lines at rear of the intake manifold.

    4. Object Number: 18333 Size: SH
  4. Remove the nuts
  5. Remove the retainer
  6. Disconnect the injector fuel inlet pipe and the outlet pipe.

    7. Object Number: 18334 Size: SH
  7. Remove the rear fuel line bracket.

    8. Object Number: 18335 Size: SH
  8. Pull straight up on fuel pipe to remove fuel pipes from injector assembly.

    9. Important: Check the injector assembly to insure the O-rings have been removed.

  9. Remove the O-ring seals from both ends of the fuel feed and return pipes and discard.

Assemble Procedure

Install the new O-rings into the inlet and outlet of the fuel injector assembly, using the seal retainer tool.

Installation Procedure

Caution: In order to reduce the risk of fire and personal injury, before connecting fuel pipe fittings, always apply a few drops of clean engine oil to the male pipe ends.

This will ensure proper reconnection and prevent a possible fuel leak.

During normal operation, the O-rings located in the female connector will swell and may prevent proper reconnection if not lubricated.

Important: Remember to install the new O-rings into the inlet and outlet of the fuel injector assembly, using the seal retainer tool.

  1. Apply a few drops of clean engine oil to the male tube ends.

    2. Object Number: 18335 Size: SH
  2. Connect the fuel feed and return pipes to fuel assembly.

    3. Object Number: 18333 Size: SH
  3. Install the fuel pipe retainer and attaching nuts. Once installed, pull on both ends of each connection to make sure they are secure.

    4. Object Number: 18334 Size: SH
  4. Install the rear fuel pipe clip retaining bolt.

    5. Tighten

        • Tighten the rear fuel line bracket bolt to 6.0 N·m (53 lb in).
        • Tighten the fuel pipe retainer nuts to 3.0 N·m (27 lb in).
  5. Install the new O-ring seals on the engine fuel feed and return pipes.

    6. Object Number: 18332 Size: SH
  6. Connect the fuel feed and return lines to the engine fuel pipes.

    7. Tighten
    Tighten the fuel pipe nuts to 30.0N·m (22 lb ft).

  7. Tighten the fuel filler cap.
  8. Connect the negative battery cable.
  9. Check for fuel leaks.
    10. 9.1. Turn the ignition switch to the ON position for 2 seconds.
    9.2. Turn the ignition switch to the OFF position for 10 seconds.
    9.3. Again, turn the ignition switch to the ON position.
    9.4. Check for fuel leaks.

Fuel Hose and Pipes Hose and Assemblies

Steel fuel lines - These are welded steel tubes, meeting GM specifications 124-M, or its equivalent. The fuel feed line is 3/8 inches diameter and the fuel return line is 5/16 inches diameter. Do not use copper or aluminum tubing to replace steel tubing. Those materials do not have satisfactory durability to withstand normal vehicle vibration.

Coupled hose - Do not repair the hoses. Replace them only as an assembly.

Uncoupled hose - Use only reinforced fuel resistant hose, made of Fluoroelastomer material. Do not use a hose within 4 inches (100 mm) of any part of the exhaust system, or within 10 inches (2154 mm) of the catalytic converter. The hoses inside diameter must match the outside diameter of the steel tubing.

Clamps - These are stainless steel, screw bank-type clamps, #2494772, or equivalent.

Steel Fuel Line Repair
  1. Cut a piece of fuel hose 4 inches (100 mm) longer than the section of line to be removed. If you remove more than 6 inches (152 mm), use a combination of steel pipe and hose. The hose length should not be more than 10 inches total.
  2. With a tube cutter, cut a section of the pipe to replace. Use the first step to form a bead on the ends of the pipe and, also, on the new section of pipe, if used.
  3. Slide the hose clamps onto the pipe and push the hose 2 inches (51 mm) onto each portion of the fuel pipe. Tighten a clamp on each side of the repair.
  4. Secure fuel line to the frame.
  5. Check for leaks.

Fuel Hose and Pipes Fuel Pipes

Removal Procedure
  1. Disconnect the negative battery cable.

    2. Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

  2. Relieve the fuel system pressure. Refer to Fuel Pressure Relief Procedure .

    3. Object Number: 18332 Size: SH
  3. Disconnect the fittings at the engine compartment fuel feed and return pipes.
  4. Disconnect the fuel pipe attaching hardware.
  5. Disconnect the fuel feed and return pipe nuts at the fuel inlet and fuel outlet assembly.
  6. Disconnect the fuel feed and return pipes and O-rings. Discard O-rings.
  7. Remove the fuel tank.
    8. • Refer to Fuel Tank Replacement (Suburban) for the Suburban.
    • Refer to Fuel Tank Replacement (Tahoe/Yukon) for the Tahoe/Yukon.
    • Refer to Fuel Tank Replacement (Pick-up - Side Tank) for the Pick-up.
    • Refer to Fuel Tank Replacement (Extended Cab - Side Tank) for the Extended Cab.
    • Refer to Fuel Tank Replacement (Cab and Chassis - Side Tank) for the Cab and Chassis with a side tank.
    • Refer to Fuel Tank Replacement (Cab and Chassis - Rear Tank) for the Cab and Chassis with a rear tank only.
    • Refer to Fuel Tank Replacement for the 4DR Utility.

    Object Number: 19204 Size: SH
  8. Disconnect the fuel feed and vapor hoses.
  9. Remove the hardware retaining section of pipe to be replaced. Note location of attaching hardware for installation.
  10. Remove the section of pipe and hoses.
  11. Remove rust or burrs from the engine compartment fuel pipes by the following procedure:
    12. 11.1. Use emery cloth in a radial motion with the fuel pipe end in order to prevent damage to the O-ring sealing surface.
    11.2. Using a clean shop towel, wipe off the male tube ends.
    11.3. Inspect all the connectors for dirt and burrs. Clean or replace the components/assemblies as required.

Cleaning and Inspection Procedure

Notice: If necessary, remove rust or burrs from the fuel pipes with an emery cloth. Use a radial motion with the fuel pipe end in order to prevent damage to the O-ring sealing surface. Use a clean shop towel in order to wipe off the male tube ends. Inspect all the connections for dirt and burrs. Clean or replace the components and assemblies as required.

Installation Procedure

Caution: In order to reduce the risk of fire and personal injury, before connecting fuel pipe fittings, always apply a few drops of clean engine oil to the male pipe ends.

This will ensure proper reconnection and prevent a possible fuel leak.

During normal operation, the O-rings located in the female connector will swell and may prevent proper reconnection if not lubricated.

  1. Install the new O-rings on the engine fuel feed and return pipes.

    2. Object Number: 18332 Size: SH
  2. Connect the fuel feed and return pipes to the fuel injection unit. Finger tighten only.
  3. Connect the fuel pipe attaching hardware.

    4. Tighten
    Fuel pipe attaching nuts to 27 N·m (20 lb ft) using a back-up wrench.

  4. Position new fuel pipe harness in original location and fuel pipe harness attaching hardware.
  5. Remove protective caps from one end of both fuel pipes.

    6. Leave caps on other end of pipes to prevent dirt from entering.

  6. Apply a few drops of clean engine oil to the male connector tube ends.

    7. Object Number: 19204 Size: SH
  7. Connect the quick-connect fittings at the fuel feed and pipe near the in-line filter and at the fuel sender assembly. Refer to Fuel Hose and Pipes (Quick Connect Fittings) for V6. Refer to Fuel Hose and Pipes for V8.
  8. Install the fuel tank and attaching hardware if the tank was removed.
  9. Tighten the fuel filler cap.
  10. Connect the negative battery cable.
  11. Check for fuel leaks.
    12. 11.1. Turn the ignition switch to the ON position for 2 seconds.
    11.2. Turn the ignition switch to the OFF position for 10 seconds.
    11.3. Again, turn the ignition switch to the ON position.
    11.4. Check for fuel leaks.

Fuel Hose and Pipes Vapor Pipes

Removal Procedure

Notice: 

   • Do not attempt to straighten kinked nylon pipes. Replace any kinked nylon pipes in order to prevent damage to the vehicle.
   • Do not attempt to repair sections of nylon pipes. Replace damaged nylon pipes.
   • Replace the vapor pipes with original equipment or parts that meet GM specifications.
   • Replace the vapor hoses with original equipment or parts meeting GM specifications. Use only reinforced fuel-resistant hose identified with the word Fluoroelastomer or GM 6163M on the hose.

  1. Remove the hardware retaining section of the pipe to be replaced. Note the location of attaching hardware for installation.

    2. Object Number: 19204 Size: SH
  2. Remove the section of the pipe and hoses.
  3. Inspect the hoses for cuts, swelling, cracks and distortion. Replace as required.
  4. Inspect the pipes for holes, kinks, and cracks. Replace the sections as required.

Installation Procedure

Important: 

   • Follow the same routing as the original pipes and hoses.
   • Secure the pipes and hoses to prevent chafing.


    Object Number: 19204 Size: SH
  1. Install the section of the pipe and hoses.
  2. Install the hardware retaining section of the pipe being replaced.

Fuel Hose and Pipes Quick Connect Fittings

Removal Procedure
  1. Grasp both sides of the fitting. Twist the female connector 1/4 turn in each direction to loosen any dirt within the fitting.

    2. Caution: Wear safety glasses when using compressed air in order to prevent eye injury.

  2. Using compressed air, blow dirt out of the fitting.
  3. Choose the correct tool from J 37088-A tool set for size of the fitting. Insert the tool into the female connector, then push inward to release the locking tabs.
  4. Pull the connection apart.

    5. Notice: Use an emery cloth in order to remove rust or burrs from the fuel pipe. Use a radial motion with the fuel pipe end in order to prevent damage to the O-ring sealing surface.

  5. Use a clean shop towel in order to wipe off the male pipe end.
  6. Inspect both ends of the fitting for dirt and burrs. Clean or replace components/assemblies as required.

Installation Procedure

Caution: In order to reduce the risk of fire and personal injury, before connecting fuel pipe fittings, always apply a few drops of clean engine oil to the male pipe ends.

This will ensure proper reconnection and prevent a possible fuel leak.

During normal operation, the O-rings located in the female connector will swell and may prevent proper reconnection if not lubricated.

  1. Apply a few drops of clean engine oil to the male pipe end.
  2. Push both sides of the fitting together to cause the retaining tabs/fingers to snap into place.
  3. Once installed, pull on both sides of the fitting to make sure the connection is secure.