Fuel flapper fix


texas mongrel

GT Owner
Mark II Lifetime
May 3, 2009
1,661
Houston Texas
I know this has been discussed at length previously, but of course I didn't pay much attention til it happened to me! Well, during the Big Bend Open Road Race last week, the hinged flapper in the fuel fill spout finally fell off. Luckily, I didn't get any check engine light and the car ran flawlessly throughout its 1800 miles of touring and racing.
When I got home I had a dilemma - leave it or fix it. Given that it was taking 15 minutes to fill the tank, and despite the fact that the car was due imminently at the Port of Houston for its big trip to Le Mans, I took a deep breath and tore into it.
Good news; all the stuff about how tricky it is to remove the fender liner is not really true. Although the factory manual talks about removing 8 screws that hold in the plastic liner, I counted 13 plastic push pins. Once they were out, a few bashes from the flat of my hand and voila! The liner rotated out quite easily. You can bend the crap out of that thing and it reatins its shape, so don't be scared of man-handling it. I used tons of masking tape around the fender lip just in case.
Removing the fill pipe assembly was also easy-peasy. Once out, I noticed that all the bits inside the pipe seemed intact, just "unassembled", so I took a Dremel tool and cut through the three little welds that hold on the fuel pipe's top flange and removed it. With a lot of wiggling this allowed me to pull out the entire plastic assembly that's supposed to contain the flapper. This also allowed the flapper pieces to fall out of the pipe. There are three parts; the flapper, the spring, and the mounting hinge. The hinge is retained by an extension 'tongue' of its lower end that fits into a hole in the side of the lower part of the filler piece, and I think this is why so many folk have issues: if this retainer pops out due to loads from a careless gas pump nozzle, then the force of the flapper's spring makes the entire assembly self-destruct. So, after I'd re-assembled everything, I added a screw through the side of the hinge and wall of the assembly. Thus, even if that little retaining tongue gets dislodged in the future, nothing will happen.
It was then only a matter of re-welding the flange back onto the filler pipe ( with some cold galvanizing paint for corrosion protection), and pushing the whole flapper unit back down into the pipe.
Re-installation went as smoothly as disassembly.
Overall time, about 4 hours, overal cost to fix $0!
Sorry, I didn't take any pictures, but it really is no big deal, and given that parts are getting harder and harder to find, this way is a no-brainer.
 

soroush

Ford Gt Owner
Mark II Lifetime
Aug 8, 2007
5,256
If memory serves me correctly someone had replaced that whole unit with a metal one from another car it may have been an F150 or something, but no more plastic.....
 

steved57

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Mar 29, 2008
1,941
kilgore tx
Mine's come loose too and is something I need to take care of
 

The Grey Ghost

GT Owner
Mar 13, 2009
685
Kansas City
I had to do this repair a few years ago.

I drilled a small hole through the "tongue" piece mentioned and put a brass cotter pin through to keep it from popping out again.

Another forum member actually ran a piece of stainless steel wire through a similar hole around the inner piece before reinstalling it in the outer section.

I have pictures of the assemblies David mentions in various stages if anyone needs them.
 

Beach-GT

GT Owner
Mark II Lifetime
May 8, 2006
887
Seminole Florida
I've used JB Weld successfully in repair of gas tank drains in the past so it can surely be used for attaching things around gasoline if necessary.