GM Service Manual Online
For 1990-2009 cars only

Tools Required

    • J 34730-262 Fuel Pressure/Test Gage Adapter
    • J 42960-2 Fuel Flapper Door Holder
    • J 45004 Fuel Tank Drain Hose

For any operation requiring removal of the fuel tank, there should be no more than 11.4 L (3 gal) of fuel remaining. This minimizes the weight of the assembly and eases handling. The fuel level can be determined by reading the fuel level gage. A reading below 1/4 full indicates that no more than 11.4 L (3 gal) are remaining.

Using The Fuel Pump

Caution: Never drain or store fuel in an open container due to the possibility of fire or explosion.

Using the fuel pump to drain the tank is the easiest procedure if the pump is operable. The fuel can be pumped out with the vehicle on the ground or on the hoist.

On The Ground

    Caution: Fuel supply lines will remain pressurized for long periods of time after the engine is shutdown. This pressure must be relieved before servicing the fuel system.

  1. Relieve the fuel system pressure. Refer to Fuel Pressure Relief .
  2. Caution: Whenever fuel line fittings are loosened or removed, wrap a shop cloth around the fitting and have an approved container available to collect any fuel.

  3. Disconnect the fuel feed line at the fuel rail and install the 3/8 x 1/4 in quick connect from the J 34730-262 into the fuel feed line.
  4. Connect a suitable drain hose to the other end of the adapter and connect the drain hose into a certified fuel handling cart.
  5. Remove the fuel pump relay from the underhood electrical center.
  6. Using a jumper wire, operate the fuel pump.
  7. Pump out the fuel until no more than 1/4 tank remains.

On The Hoist

Caution: Fuel supply lines will remain pressurized for long periods of time after the engine is shutdown. This pressure must be relieved before servicing the fuel system.

  1. Connect the scan tool to the vehicle diagnostic connector and turn the ignition ON.
  2. Relieve the fuel system pressure. Refer to Fuel Pressure Relief .
  3. Caution: Ensure that the vehicle is properly supported and squarely positioned. To help avoid personal injury when a vehicle is on a hoist, provide additional support for the vehicle on the opposite end from which the components are being removed.

  4. Raise the vehicle on a hoist to a comfortable working height, keeping the scan tool outside of the vehicle and accessible from under the car.

  5. Object Number: 871797  Size: SH

    Caution: Whenever fuel line fittings are loosened or removed, wrap a shop cloth around the fitting and have an approved container available to collect any fuel.

  6. Disconnect the chassis fuel feed line at the fuel tank.
  7. Install the 3/8 x 1/4 in quick connect (1) adapter from the J 34730-262 onto the tank side fuel feed line.
  8. Connect a suitable drain hose to the other end of the adapter, and connect the drain hose to a certified fuel handling cart.
  9. Remove the fuel pump relay from the underhood electrical center.
  10. Using a jumper wire, operate the fuel pump.
  11. Pump out the fuel until no more than 1/4 tank remains.

Siphoning The Fuel Tank

Caution: Do not allow smoking or the use of open flames in the area where work on the fuel or EVAP system is taking place. Anytime work is being done on the fuel system, disconnect the negative battery cable, except for those tests where battery voltage is required.

If the fuel pump is inoperative, the tank can be drained by siphoning from the tank. A suitable means is through the fuel filler pipe with the correct type and stiffness of tubing as used with the J 45004 .

    Caution: Do not allow smoking or the use of open flames in the area where work on the fuel or EVAP system is taking place. Anytime work is being done on the fuel system, disconnect the negative battery cable, except for those tests where battery voltage is required.

  1. Disconnect the negative battery cable.
  2. Open the fuel filler door and remove the gas cap.

  3. Object Number: 892348  Size: SH

    Notice: Do not attempt to insert any other type of siphon hose or tube into the fuel filler pipe. The design of the inlet check valve at the end of the fuel filler tube restricts the insertion of a hose and, most importantly, prevents the removal of this hose. See Fuel Inlet Check Valve in this section. If the siphon hose becomes stuck in the check valve, the fuel filler pipe will not be able to be removed from the fuel tank without damage to the fill pipe or fuel tank.

  4. Insert the J 42960-2 into the fuel filler pipe.
  5. Important: The siphon hose will reach the bottom of the tank, on the primary side only, within about 25.4 cm (10 in) of the end fitting and tag. When connecting the siphon hose to another length of hose connected to the fuel drain tanker, DO NOT insert the siphon hose into the fill pipe funnel past the tag at the fitting end. If inserted too far, the upper portion of the siphon hose may pass through the check valve cage and then jam on attempted removal.

  6. Insert the J 45004 into the guide funnel and into the fuel filler pipe. Some resistance may be encountered when the tip of the siphon hose reaches the inlet check valve. Repeated probing may be necessary to slide the hose tip through the check valve cage.
  7. Caution: Whenever fuel lines are removed, catch fuel in an approved container. Container opening must be a minimum of 300 mm (12  in) diameter to adequately catch the fluid.

    Important: The fuel flow rate from the siphon hose will range from 1.1 L/min (0.3 gal/min) up to 3.8 L/min (1 gal/min), depending on whether it is gravity siphoned or with an air-powered pump.

  8. Begin the fuel siphoning process. Place the fuel into an approved fuel container.
  9. Remove the siphon hose and the fuel flapper door holder from the fuel filler pipe after draining is complete.