GM Service Manual Online
For 1990-2009 cars only

Fuel Hose/Pipes Assembly Replacement Fuel Pipe Repair

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 on the reamer 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/Pipes Assembly Replacement Fuel 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.

    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 Fuel Pressure Relief Procedure .

  3. Object Number: 420627  Size: SH
  4. Disconnect the fittings (1) at the engine compartment fuel feed and return pipes.
  5. Disconnect the fuel pipe attaching hardware (2).

  6. Object Number: 420628  Size: SH
  7. Disconnect the fuel feed and return pipe quick connects at the fuel filter and the fuel return pipe.

  8. Object Number: 420629  Size: SH
  9. Remove the hardware retaining section of pipe to be replaced (1). Note location of attaching hardware for installation.

  10. Object Number: 420630  Size: SH
  11. Remove the section of pipe and hoses.
  12. Remove rust or burrs from the engine compartment fuel pipes by the following procedure:
  13. 8.1. Use emery cloth in a radial motion with the fuel pipe end in order to prevent damage to the O-ring sealing surface.
    8.2. Using a clean shop towel, wipe off the male tube ends.
    8.3. Inspect all the connectors for dirt and burrs. Clean or replace the components/assemblies as required.
    8.4. Disconnect the fuel feed and return pipe quick connects at the fuel tank pipe harness (2).
    8.5. Remove the section of fuel pipe from the hardware retaining mounts (1).
    8.6. Remove the fuel tank.
    8.7. Refer to Fuel Tank Replacement (Passenger/Cargo Van) and Fuel Tank Replacement (Commercial/RV Cutaway Van) .

Installation Procedure


    Object Number: 420627  Size: SH

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  1. Connect the fuel feed and return pipes to the engine fuel pipes (1).
  2. Tighten
    Fuel pipe attaching nuts to 27 N·m (20 lb ft) using a back-up wrench.

  3. Position new fuel pipe harness in original location and fuel pipe harness attaching hardware (2).

  4. Object Number: 420628  Size: SH
  5. Connect the fuel feed pipe to the fuel filter and connect the fuel return pipes together.

  6. Object Number: 420629  Size: SH
  7. Install the new section of fuel feed and return pipe making sure that they are fully seated into the pipe attaching hardware (1).

  8. Object Number: 420630  Size: SH
  9. Install the fuel tank and attaching hardware (1) if the tank was removed. Refer to Fuel Tank Replacement (Passenger/Cargo Van) and Fuel Tank Replacement (Commercial/RV Cutaway Van) .
  10. Connect the fuel feed and return pipe quick connects fittings at the rear frame rails (2).
  11. Tighten the fuel filler cap.
  12. Connect the negative battery cable.
  13. Check for fuel leaks.
  14. 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.