The gas tank on the Goldwing isn't actually a gas tank. It is a "false tank", or "shelter". The gas tank is actually located under the seat, next to the battery. Under the false tank is located most of the electrical components for the motorcycle, the filler neck for the gas tank, and either a storage area, or the air compressor and valves for the air suspension, depending on the model of Goldwing that you own.Removal
1. Remove the seat. Instructions on how to do this can be read here
2. Remove the fairing lowers. Instructions on how to do this can be read here
3. Remove the two bolts holding the back of the false tank to the motorcycle frame crossmember.
4. Looking in through the side of the motorcycle where the fairing lowers normally go, you will see two bolts recessed in a few inches, almost directly above the radiator. Using a socket extension, reach into the space exposed by the fairing lower panels, immediately below the fairing, and remove the bolts holding the front of the false tank to the motorcycle frame (one on each side).
If your motorcycle does not have air suspension installed, then skip forward to step 15: steps 5 through 14 involve disconnecting the air suspension before removing the false tank.
5. Put a wrench on the smaller of the two nuts on the hose fitting on the top of the right shock.
6. Put a larger wrench on the larger of the two nuts. The smaller wrench is not shown in this picture, for clarity. While holding the smaller wrench still (preventing the smaller nut from moving), loosen the larger nut. After a turn or so, it should be able to be removed with your fingers. Unscrew it and pull the hose away from the fork fitting.
7. Remove the right side cover and repeat the same removal procedure on the rear suspension air fitting.
8. Open the false tank lid. Remove the banjo fitting from the top left of the compressor. Don't lose the O-ring!
9. Remove the left rearmost fitting from the bottom of the air suspension control panel, under the tank lid. Again, don't lose the O-ring!
10. Disconnect the air compressor power plug.
11. Pull the air compressor up and out of the false tank.
12. Pull the rear suspension air hose out of the frame and up through the middle of the false tank.
13. Ensure the front suspension air hose is clear of any obstruction.
14. Disconnect all four wire bullet connectors leading to the air suspension control panel. Don't worry - all the wires are different colors, so you can't mix them up on reassembly. Make sure you pull on the connectors to disconnect them, not the wires.
15. Gently pull the back of false tank up slightly, then to the rear of the motorcycle, and lastly pull it up and away from the motorcycle. Set it down on something soft to avoid chipping or scratching the paint.Reinstallation
16. To reinstall, gently position the tank in place, and allow the front of the tank to move into place before the rear. You may have to spread the tank halves (the tank is made of two halves bolted together) slightly in order to get it to fit correctly.
17. Ensure the front bolt holes of the tank slide over the outside of the frame mounting tabs, as shown in this picture. In this picture, the tank bolt holes (top) are sliding correctly over (on the outside of) the frame mounting tabs. Make sure this is done on both sides before installing any bolts!
If your motorcycle does not have air suspension installed, then skip forward to step 32: steps 18 through 31 involve reconnecting the air suspension.
18. Ensure the front air hose comes out the front of the tank.
19. Route the rear air hose underneath the frame, and under the helmet lock...
20. ...and under the engine mount and frame member as shown.
21. Place the rear hose on the fitting, and tighten it finger tight.
22. Holding the smaller nut from moving, tighten the larger nut on the fitting.
23. Perform the same operation to fasten the front hose onto its fitting.
24. Ensure that the front hose is routed correctly next to the fuse block.
25. Reconnect the wires from the compressor control panel. Note each color matches the color of the wire it is connected to.
26. Insert the air compressor into its position under the false tank. Fasten the smaller banjo air fitting to the air compressor. Note the position of the O-rings.
27. Righten the fitting in place. Note that the hose exits between the two metal protrusions on the air compressor.
28. Fasten and tighten the banjo air fitting to the compressor control panel.
29. Reconnect the power connector for the air compressor.
30. Arrange the compressor and its hoses correctly within the false tank cavity, and close the tank cover.
31. Turn the key switch on, and pressurize the front and rear suspensions to check for proper operation.
32. A trick for holding nuts or bolts in a socket wrench, when they may fall out: place a piece of a shop towel on the head before inserting it into the socket, and it will be held firm.
33. Install, but do not tighten the front bolts.
34. Install and tighten the rear bolts. Once they are tightened, fully tighten the front bolts.
35. Replace the fairing lowers. Instructions on how to do this can be read here
36. Replace the seat. Instructions on how to do this can be read here