The International Cessna^® 170 Association

I know this has been discussed & rediscussed but I just replaced the gaskets on my fuel tank filler neck & adapter & after all the discussion I put a gasket inside the tank & one outside the tank in spite of the fact that the IPC shows in fig 2 & fig 7 that there is no gasket inside the tank.The result being that the adapter is now one gasket thickness deeper into the tank witch causes the adapter not to be at the proper height to mate with the skin of the tank cover panel.It is enough dif to cause the skin to be distorted when the screws are tightened that attach the skin panel to the adapter.The solution is to either remove the whole works again & remove the gasket on the inside of the tank so it will return to the original height or add another thickness of gasket to the adapter under the skin panel.I opted for the latter & was able to lift the panel enough to slip the extra gasket under the skin panel by removing the eight screws that attach the skin panel to the adapter.Just more of FWIW

Z, there is one under the skin, between the flange and tank cover. Ron

Yep you are absolutely correct on that.The IPC shows one under the tank adapter & one on top of the tank adapter between it & the skin of the tank cover.I put one inside the tank one outside the tank & two on top of the adapter between it & the skin to take up some of the space there that was causing the skin to distort.But I was wrong about the gasket inside the tank causing that gap.It wouldn't matter how far down into the tank that the filler neck flange went because the tank adapter height is only decided by the top of the tank.I realized my error in thinking after I posted it & was hoping I got back to the computer before anybody read it but didn't make it I see!Well it sure ain't the first time I ever got egg on my face & hope it wont be the last!

Timing is everything they say! It happens that I am sitting here looking for sources of these gaskets myself. As I understand it we need 3 gaskets per tank, two of them being identical and the one inside the tank being a different size. Where did you locate the gaskets and what did you have to pay for them?

Frank you starting this project back in May. See http://www.cessna170.org/forums/viewtop ... nk+gaskets

At this rate I'll cut a couple of these things and give them to you at next convention.

Yes there are two different sizes. You can see what they look like and get the part numbers of the PDFs linked in that same thread.

Frank, the two in the tank are the same size. the one on top under the cover skin is the lagre 8 hole one. they are easy to change, a piece of wire with a hook will pull the old gasket out of the tank. After you undo the screws around the filler neck. just hold it bythe chain and let it lower--hook the old gasket with the wire and pull it up. slide the new gasket over the chain and push it thru the filler neck and then align the holes in both gaskets and the cover plate the big gasket goes under the skin. Ron.

Yes Bruce, I started looking into this project some time ago and am now looking to do it right after Thanksgiving. Too hot in the hangar during the summer, plus I don't want the plane "down" until later. I am going to go ahead and pull the tanks out, inspect them, replace anything that is needed along with the rubber hoses that were installed in 1956. While I am at it I will rewire the speaker & probably replace it as well as making sure the insullation I put in back in 1990 is OK or replace it. Jim Wildharber's instructions on how to do the tanks is an excellant step-by-step procedure (thanks Jim). What I was hoping to find was a source for the 6 gaskets that wouldn't cost $70.00.

170C wrote:Yes Bruce, I started looking into this project some time ago and am now looking to do it right after Thanksgiving. ..... What I was hoping to find was a source for the 6 gaskets that wouldn't cost $70.00.

I refer you back to the thread I linked to earlier with the PDF patterns of the gaskets you will need. If you start cutting today, I'm sure you will have six suitable gaskets by Thanksgiving without spending more than $20 in gasket material.

Bruce/George--thanks again for the suggestions, etc.
The rubber hoses needed to replace those on the fuel tank vent lines and fuel tanks to fuel lines, etc. Approximately how many feet of hose might be required and what size?