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 System Cleaning

Removal Procedure

    Object Number: 317985 Size: SH
  1. Remove the fuel feed (2) and the return pipes at the TBI unit.
  2. Remove the fuel feed and the return pipes at the fuel sender assembly.

    3. Object Number: 319507 Size: SH
  3. Remove the in-line fuel filter.
  4. Inspect the in-line fuel filter for contamination.
  5. Replace the filter, if it is plugged. Refer to In-Line Fuel Filter Replacement .

    6. Important: 

       • Only use oil free compressed air to blow out fuel pipes.
       • If the in-line fuel filter is plugged, inspect the fuel tank internally and purge if necessary.

  6. Clean the fuel lines by applying air pressure in the opposite direction of the fuel flow.

Installation Procedure

    Important: Take care not to fold over or twist the strainer, when installing the sending unit, as this will restrict fuel flow.

  1. Install the new strainer (if necessary) on the fuel sender assembly.
  2. Install the fuel sender assembly with a new seal into the fuel tank.
  3. Install the fuel tank. Refer to Fuel Tank Replacement - Right Side and Fuel Tank Replacement - Left Side .
  4. Disconnect the fuel feed pipe at the TBI unit.
  5. Connect the hose to the fuel feed pipe at the TBI unit.
  6. Insert the other end of the hose into a 3.8 liter (1.0 gallon) fuel can.
  7. Connect the negative battery cable.
  8. Add 23 liters (6.0 gallons) of clean fuel into the fuel tank.
  9. Purge the fuel pump and the lines.
    10. 9.1. Disconnect the fuel pump oil pressure switch electrical connector.
    9.2. Connect a fused jumper between the fuel pump signal circuit and the battery feed circuit at the electrical connector.
    9.3. Operate the fuel pump until 2 liters (½ gallon) of fuel flows into the fuel can.
  10. Install the jumper and reinstall connector.
  11. Install the fuel line at the TBI unit.
  12. Check for fuel leaks using the following process:
    13. 12.1. Turn the ignition switch ON for 2 seconds.
    12.2. Turn the ignition switch OFF for 10 seconds.
    12.3. Turn the ignition switch ON.
    12.4. Check for fuel leaks.