GM 25798121
Fuel Tank

The required tools for substituting a Fuel Tank module on short wheelbase vehicles include the fuel sender lock nut wrench (J 45722). The work starts by uninstalling the Fuel Tank and disconnecting electrical connectors that belong to the Fuel Tank harness from the module. Cleansing all fuel pipe and hose attachments with no-contamination procedures takes place before hose disconnection. Take off the fuel feed pipe quick connect fitting (5) and the evaporative emission (EVAP) pipe quick connect fittings (6) from the device module. A long breaker-bar along with the fuel sender lock nut wrench (J 45722) will help unlock the fuel sender lock ring through counterclockwise turning while you drain fuel into an approved container for fire risk reduction. Extract the Fuel Tank module together with its seal while discarding the previous seal and proceed to clean both sealing areas. Check the lock ring for damage as well as measure its warpage; replace it if the warpage measures more than 0.41 mm (0.016 in). Install the new Fuel Tank module seal with caution while avoiding Fuel Pump Strainer twisting before setting the module inside the Fuel Tank. Install the fuel sender seal first then place the lock ring with its correct orientation upward before tightening it by hand with the fuel sender lock nut wrench (J 45722). Complete the installation by reattaching both evap pipe quick connect fittings, the fuel feed pipe quick connect fitting and all Fuel Tank harness electrical connectors before installing the Fuel Tank.

You need to use the fuel sender lock nut wrench (J 45722) to replace the Fuel Tank module of a long wheelbase vehicle. Start by taking off the Fuel Tank followed by disconnecting wires from the Fuel Tank module. All fuel pipe and hose connections require cleaning before any disconnect procedure becomes necessary to avoid contamination. The first step is to disconnect both quick connect fittings that lead the fuel feed pipe and the evaporative emission (EVAP) pipe from their module positions. Unlock the fuel sender lock ring through counterclockwise rotation using the fuel sender lock nut wrench (J 45722) together with a long breaker-bar while draining the fuel to safe containers as a fire precaution. Extract the Fuel Tank module with its seal while disposing of the aging module seal then clean both sealing areas. Check for damage on the lock ring while also measuring its warpage against 0.41 mm (0.016 inches); perform a replacement if warpage exceeds this measurement. The installation of a new Fuel Tank module requires users to place a fresh Fuel Tank module seal on the Fuel Tank so the Fuel Pump Strainer remains untwisted and unfolded. Place the new Fuel Tank module into the Fuel Tank before securing the lock ring through clockwise rotation of the fuel sender lock nut wrench (J 45722). The procedure ends by reconnecting the evap quick connect fittings, the fuel feed pipe quick connect fitting, the Fuel Tank harness electrical connectors, and placing the Fuel Tank back in position.

Remove the module and seal from the fuel tank, discarding the old module seal and cleaning the sealing surfaces.

Reconnect the EVAP pipe and fuel feed pipe quick connect fittings, reconnect the fuel tank harness electrical connectors, and reinstall the fuel tank.