CTS 2003-2005

Removal & Installation


GM considers a fuel tank to be a major component and they caution that additional support is required if the vehicle is on a hoist. Support the opposite end of the vehicle, chaining the vehicle frame rails to the hoist pads to avoid the vehicle tipping off the hoist. Failure to follow these precautions could lead to vehicle damage, serious personal injury or death.

Do not attempt to straighten any kinked nylon fuel lines. Replace any kinked nylon fuel feed or return lines to prevent damage to the vehicle. Do not attempt to repair damaged lines; replace any damaged lines. Do not bend the fuel tank straps as this may damage the straps and make installation difficult. There are a number of fuel tank and evaporative emission lines that have to be disconnected. Tag for identification all lines to avoid installation mistakes. Due to model variations, some procedures for some vehicles may differ slightly. The following should suffice for all W-Body vehicles.

  1. Disconnect the negative battery cable.
  3. Relieve the fuel system pressure using the procedures found in this section.
  5. Drain the fuel tank using the procedures found in this section.
  7. Raise and safely support the vehicle.
  9. Remove the EVAP hose from the fuel tank
  11. Remove the fuel tank filler hose from the fuel tank.
  13. Separate the quick-connect fittings at the fuel tank using the procedures found in this section.
  15. Remove the EVAP pipe from the connection at the front of the tank.
  17. Remove the rubber exhaust pipe hangers, allowing the exhaust system to drop slightly.
  19. With the aid of an assistant, support the fuel tank and remove the fuel tank strap bolts. Lower the tank enough to detach the electrical connector. Carefully lower the tank and remove to a safe, suitable work area.
  21. If the tank is being replaced with a new tank, transfer any components as required including any insulator pads, fuel line clips and the fuel sender assembly.

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Fig. Typical fuel tank mounting arrangements

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Fig. Typical fuel tank insulator mounting positions

To install:

  1. Clean all parts well. Inspect the tank for dents, rust or other damage. On high-mileage vehicles, it may be good practice to either replace the fuel sender module as an assembly (includes a new fuel pump) or at least replace the flexible fuel strainer on the bottom of the module.
  3. Position the tank to the vehicle and install the quick-connecting fittings using the procedures found in this section. Secure the electrical connection. With the aid of an assistant, position and support the tank and connect the EVAP pipe to the rear of the fuel tank and to the fuller filler pipe. Position the tank straps and tighten the strap bolts to 35 ft. lbs. (47 Nm).
  5. Install the exhaust hangers and make sure the exhaust system is properly positioned and supported.
  7. Lower the vehicle. Add fuel and connect the negative battery cable. Test for leaks.