GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2004 🢒 TopKick C-Series (Conventional) C4/C5 🢒 Engine 🢒 Engine Mechanical - 6.6L (LB7) 🢒 Fuel Junction Block Replacement

Removal Procedure
  1. Move the hood to the service position, by moving the hood hinge bolts (1) to the service positions (2).
  2. Disconnect the batteries negative cables. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  3. Remove the upper intake sight shield using the following procedure:
    4. 3.1. Remove the retaining bolt in the front of the shield.
    3.2. Lift up on the front of the shield.
    3.3. Lift the shield off the rear bracket.
  4. Drain the engine coolant. Refer to Cooling System Draining and Filling in Engine Cooling.
  5. Remove the drive belt. Refer to Drive Belt Replacement in Engine Mechanical.

    6. Object Number: 652573 Size: SH
  6. Relocate the air conditioning (A/C) compressor using the following procedure:
    7. 6.1. Disconnect the A/C compressor clutch electrical connector.
    6.2. Disconnect the A/C cut out switch electrical connector.
    6.3. Remove the A/C compressor mounting bolts.
    6.4. Reposition the A/C compressor with the hoses attached to the right side of the engine compartment.

    Object Number: 759733 Size: SH
  7. Disconnect the left front injector harness connector (1).
  8. Disconnect the oil pressure sending unit harness connector.

    9. Object Number: 668427 Size: SH
  9. Disconnect the turbocharger coolant hose and clamp from the turbocharger bypass valve.

    10. Object Number: 699329 Size: SH
  10. Disconnect the water outlet tube using the following procedure:
    11. 10.1. Remove the 2 bolts retaining the water outlet tube to the left valve rocker arm cover.
    10.2. Remove the bolt retaining the water outlet tube to the thermostat housing.
    10.3. Remove the water outlet tube.
    10.4. Remove and discard the O-ring seal.

    Object Number: 687021 Size: SH
  11. Disconnect the positive crankcase ventilation (PCV) hose from the upper valve rocker arm cover.

    12. Object Number: 664853 Size: SH

    Important: Do not use a screwdriver or other tool to pry the hose loose. The hose can be torn or damaged. Loosen the hose by twisting.

  12. Loosen the charged air cooler inlet duct to turbocharger clamp and remove the inlet duct.

    13. Object Number: 755766 Size: SH
  13. Disconnect the banjo bolt (1) from the junction block.
  14. Disconnect the three fuel pipes (3) from the junction block.

    15. Object Number: 755759 Size: SH
  15. Disconnect the other end of fuel pipe junction block to the fuel rail (1).
  16. Remove the two nuts holding the junction block.
  17. Remove the junction block.

Installation Procedure

    Object Number: 660442 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. Install the junction block and the two nuts holding the junction block.

    2. Tighten
    Tighten the nuts to 25 N·m (18 Ib ft).


    Object Number: 755766 Size: SH
  2. Install the fuel system return line banjo bolt (1) to the junction block.

    3. Tighten
    Tighten the fuel return line banjo bolt to 15 N·m (11 lb ft).

  3. Connect the three fuel pipes (3) to the junction block.

    4. Tighten
    Tighten the high pressure fuel lines to 44 N·m (32 lb ft).


    Object Number: 755759 Size: SH
  4. Connect the other end of the pipe (1) to the left fuel rail.

    5. Tighten
    Tighten the high pressure pipe from the junction block to the left fuel rail to 44 N·m (32 lb ft).


    Object Number: 664853 Size: SH
  5. Install the charged air cooler inlet duct to turbocharger charged air cooler outlet. Align the marks on the hose and the intake manifold duct.

    6. Tighten
    Tighten the charged air cooler clamp to 6 N·m (53 lb in).


    Object Number: 687021 Size: SH
  6. Install the PCV hose to the upper valve rocker arm cover.

    7. Object Number: 699329 Size: SH
  7. Install the water outlet tube using the following procedure:
    8. 7.1. Install a new O-ring seal on the water outlet tube.
    7.2. Lightly lubricate the O-ring seal with coolant.
    7.3. Install the water outlet tube.
    7.4. Install the bolt retaining the water outlet tube to the thermostat housing.

    Tighten
    Tighten the water outlet tube to thermostat housing bolt to 21 N·m (16 lb ft).

    7.5. Install the 2 bolts retaining the water outlet tube to the valve rocker arm cover.

    Tighten
    Tighten the water outlet tube to valve rocker arm cover bolts to 21 N·m (16 lb ft).


    Object Number: 668427 Size: SH
  8. Install the turbocharger coolant hose and clamp from the turbocharger bypass valve.
  9. Connect the oil pressure sending unit harness connector.

    10. Object Number: 759733 Size: SH
  10. Connect the left front injector harness connector (1).

    11. Object Number: 652573 Size: SH
  11. Install the A/C compressor using the following procedure:
    12. 11.1. Install the A/C compressor mounting bolts.

    Tighten
    Tighten the A/C compressor mounting bolts to 50 N·m (37 lb ft).

    11.2. Reconnect the A/C cut out switch electrical connector.
    11.3. Reconnect the A/C compressor clutch electrical connector.
  12. Replace the drive belt. Refer to Drive Belt Replacement in Engine Mechanical.
  13. Fill the engine coolant. Refer to Cooling System Draining and Filling in Engine Cooling.
  14. Install the upper intake manifold sight shield.

    15. Tighten
    Tighten the upper intake manifold sight shield bolt to 9 N·m (80 lb in).

  15. Install the fuel cap.
  16. Connect the negative batteries cables to both batteries. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  17. Position the hood in the normal operating position by moving the hood hinge bolts from service position (2) to normal operating position (1).

    18. Tighten
    Tighten the bolts to 25 N·m (18 lb ft).

  18. Purge air from the fuel system. Refer to Fuel Feed Pipe and Return Pipe Purging .