GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1998 🢒 Chevrolet C-Series Medium Duty Truck B7 🢒 Engine 🢒 Engine Controls - 6.0L and 7.0L 🢒 Fuel Vapor Pipe Assembly Replacement

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 .

    3. Object Number: 337479 Size: SH
  3. Remove the quick-connect fittings at the frame (1). Refer to Metal Collar Quick Connect Fitting Service and Plastic Collar Quick Connect Fitting Service .

    4. Object Number: 319507 Size: SH
  4. Remove the quick-connect fittings(1) at the fuel sender assembly (2). Refer to Metal Collar Quick Connect Fitting Service and Plastic Collar Quick Connect Fitting Service .
  5. Remove the hardware retaining section of pipe to be replaced.

    6. Observe the location of attaching hardware for installation.

  6. Remove the section of pipe and hoses.
  7. Inspect the hoses for cuts, swelling, cracks and distortion. Replace as required.
  8. Inspects 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 properly in order to prevent chafing.

  1. Install the section of pipes and hoses.
  2. Install the hardware retaining section of the pipe being replaced.

    3. Object Number: 319507 Size: SH
  3. Install the quick-connect fittings (1) at the fuel sender assembly (2). Refer to Metal Collar Quick Connect Fitting Service and Plastic Collar Quick Connect Fitting Service .

    4. Object Number: 337479 Size: SH
  4. Install the quick-connect fittings at the frame (1). Refer to Metal Collar Quick Connect Fitting Service and Plastic Collar Quick Connect Fitting Service .
  5. Tighten the fuel filler cap.
  6. Connect the negative battery cable.
  7. Check for fuel leaks using the following procedure:
    8. 7.1. Turn the ignition switch to ON position for 2 seconds.
    7.2. Turn the ignition switch to OFF for 10 seconds.
    7.3. Turn the ignition switch to ON position.
    7.4. Check for fuel leaks.