A. Testing Inlet Check Valve Operation (Smoke Test)

NOTE:
Fuel level in the tank is not critical to perform this test.

1. Open the fill cap door and slowly remove the gas cap.

2. Raise the vehicle on an appropriate hoist using the proper lift points.





3. Disconnect the vent tube quick connect located next to the filler tube (Figure 1).





4. Using Miller Special Tool 9790-3, plug the vent tube on the fuel tank side of the quick connect fitting (Figure 2).





5. Disconnect the carbon canister vent tube quick connect fitting from the canister (Figure 3).





6. Connect the Smoke Machine Adapter (Special Tool 9790-2) to the canister vent tube quick connect fitting (Figure 4).

7. Connect the other end of the Smoke Machine Adapter (Special Tool 9790-2) to the black discharge hose on the Smoke Machine (Special Tool 8404 or 8404A).

8. Lower the vehicle.

9. Turn on the Smoke Machine (Special Tool 8404 or 8404A) and inject smoke into the canister vent tube, filling the fuel tank for approximately 30 seconds.

> If smoke comes out of the fuel filler tube, continue with Section "B" Replace the Fuel Tank.

> If no smoke comes out of the fuel filler tube, continue with Step 10 of this procedure.

10. Turn off the Smoke Machine.

11. Apply a small amount of engine oil to the rubber plunger located on the end of the Probe Tool (Special Tool 9790-1). This will aid in the insertion and removal of the tool.





12. Insert the probe tool filler tube adapter into the filler tube opening (Figure 5). The filler tube adapter is part of the probe tool.

CAUTION:
To prevent tool damage the filler tube adapter must be installed before inserting the probe tool.





13. Insert the Probe Tool (Special Tool 9790-1) until the handle of the tool is bottomed against the filler tube adapter (Figure 6). This will open the fuel tank inlet check valve. A slight burst of pressure and smoke will indicate that the inlet check valve has been opened. Keep the probe tool fully inserted for five seconds.

NOTE:
You may feel some slight resistance when inserting or removing the tool. This is due to the probe tool making its way around the various bends in the filler tube. This is a normal condition.

14. In an attempt to get the inlet check valve to stick in the open position, slowly remove the probe tool from the filler tube.

15. Turn on the Smoke Machine (Special Tool 8404A) and begin injecting smoke into the tank through the canister vent tube.





16. Watch for smoke exiting the fuel filler tube opening:

> If no smoke is seen coming out of the fuel filler tube, the valve is working properly. Repeat Steps 13 through 16 a second time to verify that the valve is working properly. If no smoke comes out of the fill tube opening during both attempts, continue with Step 17 of this procedure.

> If smoke comes out of the fuel filler tube opening, the inlet check valve is defective. Continue with Section B Replace the Fuel Tank.

17. Turn off and disconnect the Smoke Machine (Special Tool 8404A) from the canister vent line.

18. Connect the canister vent line to the carbon canister.

19. Remove the Vent Tube Plug (Special Tool 9790-3) installed in the vent tube and reconnect the vent tube quick connect.

20. Install the gas cap and close the fuel door.

21. Return the vehicle to the customer.