MTFCA Forum

Need more discussion on how to get the gas cap off my 1927 coupe tank.

Had to split one open once and pull the pieces to remove. Original caps are zinc pot metal and threads lock to the steel tank fitting if left for years fastened in place

Clean it off real good and hot-glue a very large nut to it. Try to find a nut nearly the size of the cap. Use an impact tool.

Adam, the exhaust large brass nut that secures the exhaust pipe to the exhaust manifold fits the bill, but I seriously doubt that hot glue will hold. It is a good idea though, only use the strongest two part epoxy you can find. The photo show one that is almost 4000 psi, hitch is very strong. If you don’t have an exhaust manifold nut wrench specifically made for the nut, a Stilson wrench will work. If the glue holds, and helps you to remove the cap, soak the cap in sealed container of lacquer thinner until the epoxy let’s go, then return your exhaust nut back to where it belongs. Jim Patrick

I have often found that pouring boiling water on the cap will cause a rapid expansion which will crack the seal. If this doesn't work on the first attempt try the boiling water, leave for 2 to 3 minutes and then douse with cold water. Good luck!

I assume there is no gas or fumes in the tank, correct? You might heat it with a heat gun and tap around the edges with a small hammer.

Fumes in gas tanks can remain very long after the last tank of gas.

Have you tried two people with flat punches and hammers tapping at the same time? Might be able to save the cap if you do it this way. I wouldn't get anywhere near the tank with a torch. Any remaining fumes could cause a bomb!
Norm

You are probably going to have to break it off. I bought a NOS gas tank many years ago at Chickasha. It had the late style cap that you have. That is how I got it off. The copies that Langs sells I understand are very nice.

Flush any remaining liquid gasoline from the tank with water then remove the gas fumes from the tank by displacing the gas fumes with nitrogen gas through the outlet. This is what welding shops do when they have to perform welding work on a tank. Jim Patrick

jiminbartow wrote: ↑

Fri Feb 05, 2021 4:45 pm

Adam, the exhaust large brass nut that secures the exhaust pipe to the exhaust manifold fits the bill, but I seriously doubt that hot glue will hold. It is a good idea though, only use the strongest two part epoxy you can find.

5CFDDC20-AF5C-478A-AFAF-F3BDA7A28E81.jpeg

Hot glue is easy to remove. The Worlds Strongest Epoxy doesn’t sound like much fun to deal with unless you are just going to throw the cap away.

I do agree that a zinc die cast cap that is stuck because it is swollen will probably never come out with a nut hot-glued to it, In this case, the cap is probably junk anyway but many times the cap is stuck tightly because it was put on without a gasket. In this case, it should only take the shock of the first one or two rattles with a small impact to loosen it.

I would imagine he doesn’t want to harm his cap. Generally I just carefully tap the fins with a hardwood block, or sometimes use two vise-grips, but both those methods have to be done with a great deal of finesse and care. If that isn’t within ones skill level, you quickly have a cap with broken ears.

Cold chisel, brass hammer and have at it! Try not to drop any small or large chunks in the tank.

Face it the cap is a gonner, you are not going to save it. Do as suggested, get the cold chisel and go for it. Use a vacuum to suck out the small parts that fall in the tank. The entire center of the cap may be gone and the ring with threads will still be stuck to the tank which may require careful work with a hack saw blade to break the ring of threads. Once broken the threads can be taped out with a pointed chisel.

If it were me, before consulting "Bigger Hammer Enterprises", I would drill two holes in the cap just inside the threaded ridge of the cap And using a piece of strap steel, drill two similar sized holes (maybe 5/16") at the same spacing. Put two one inch long +/- bolts in the strap holes to create a 'wrench' that will engage the holes in the cap. Then I would gently tap the wrench handle with a small hammer while applying moderate torque. Work it alternately in both directions of the thread. If you can get the cap to rotate just slightly, more penetrating oil on the threads and more back and forth on the wrench might get it. You could get fancy, weld a nut on the face of the strap between the bolts and use your impact wrench (on a low torque setting ) on the nut to coax the cap to turn. Put heavy grease in the flutes of the drill bit to capture chips from drilling the cap if you are worried about stuff getting inside the tank.

The cap has been on for 60 years so I am not concerned about fumes. Having said that, I think I will take it off in pieces. Any more suggestions on how to do this would be appreciated. I am a little concerned about pieces getting into the tank, especially very small particles.

Bruce, You don't say if it is in or out of the car but, if it is out you could lay it across a couple of sawbucks upside down and try what Jim b. suggested. Being upside down would keep most of the particles out or near the opening even if you decide to get more aggressive with it. Jim

You're over thinking this whole process and making it much harder then it really is. Cut, drill, pound, beat, hammer, smash the cap and get it off. You can always take a shop vacuum and suck out any debris in the tank.

That aged zinc cap with split easy with a small chisel. Tap it on the side, and the threaded ring will break away. Then pry it up with a small blunt tool. The pieces will be big. As Jack posted, any small pieces that could fall in will flush out fine when cleaning the old tank insides.


Some get ragged on the edges even when newer, from screwdriver tip jabbing with a hammer ,as those caps can stick. I always coat the threads from time to time with Vaseline to lube them.

Removing the tank from a 27 coupe, then replacing it just quadrupled the work and language of removing the gas cap.

If you decide to drill and/or bust out the cap or whatever you do, it probably will be much easier if you just remove the tank from the car. ‘26-‘27 coupe & tudor tanks are easy to remove & reinstall (so long as you can get the sediment bulb off). It’s probably only a 15 minute job to remove that tank and you’re probably going to have to clean it out and leak test it anyway . ‘26-‘27 Roadster and touring tanks are the ones people have big problems removing & reinstalling (unless you’ve previously done a few and know the routine).

BLB27 wrote: ↑

Sat Feb 06, 2021 4:57 pm

The cap has been on for 60 years so I am not concerned about fumes. Having said that, I think I will take it off in pieces. Any more suggestions on how to do this would be appreciated. I am a little concerned about pieces getting into the tank, especially very small particles.

https://mtfca.com/phpBB3/viewtopic.php? ... ap#p124724
You have never indicted what style gas cap you have either in this discussion or the previous one. If we are to assume it is a "complete" pot metal style cap with the bottom plate as shown in the picture - that would help prevent pieces from falling in if you gently attack the top. BUT as Adam said in the previous discussion "There is a paper “gas cap gasket” that goes on the cap. 90% of its job is preventing the cap from “taking a set” and getting stuck. " So have you tried running a knife edge around the cap to separate it from the gasket or tank?
Jim's suggestion to epoxy a nut to the top of the cap is also a good idea to prevent pieces from falling in.
I would have a vacuum handy to remove any pieces that break off as you go.
If you remove the tank work on it (drilling or shipping) upside down so nothing falls in

Anyone who knows Model T's knows what a 1927 gas cap looks like! That style cap was introduced in 1925. I have an original on my car, and it works fine. Some of them survived, but most haven't. As I noted in an article I wrote years ago for the Vintage Ford, you will often fine the anti splash insert at the bottom of the tank. Mine fell out a few years back, and I dabbed Krazy Glue around the edge, and it has held for years.

Original Smith wrote: ↑

Sun Feb 07, 2021 11:18 am

Anyone who knows Model T's knows what a 1927 gas cap looks like! That style cap was introduced in 1925. I have an original on my car, and it works fine. Some of them survived, but most haven't. As I noted in an article I wrote years ago for the Vintage Ford, you will often fine the anti splash insert at the bottom of the tank. Mine fell out a few years back, and I dabbed Krazy Glue around the edge, and it has held for years.

Bruce has never never indicated what cap style cap he has (in words or pictures), only that he has a 1927 coupe tank! As you well know not all Model T's have been maintained with the correct part/year. I inserted the picture of the pot metal cap, not Bruce. So we still don't know

It is a pot metal cap.

BLB27 wrote: ↑

Sun Feb 07, 2021 1:38 pm

It is a pot metal cap.

I like the idea of epoxying a nut on the top of the cap. If the top breaks then chip away the rest and try and salvage the splash insert on the bottom of the cap as shown in the photo. As Larry noted it is often missing and a desirable piece to restore an original. You might use some sticky tape on the cap as you go to capture the broken pieces and the splash insert.

The epoxy can easily be removed by immersing the cap and nut in a covered bowl of lacquer thinner (covered so it will not evaporate). It may take several days or a week, but the lacquer thinner will eventually soften and loosen the epoxy and the nut will drop off. Jim Patrick

Seeing i know nothing of model T's Dan's picture was the first i have seen of this cap. The center looks heavy enough to try a Easy Out??? Bud.

I got mine out using Gibbs penetrating fluid. I used plumbers putty and built a dam around the neck of the tank so as to make a pool of Gibbs soaking the threads continuously. I smacked with a hammer daily and filled the pool daily. Did this for a week. Took the cap off with a barrel bung wrench. The cap came off in once piece but I did not use it again. Replaced it with a brass one.

https://youtu.be/ltZP_mkGINQ


This guy has no problem getting the gas cap out! Check it out.

Tmooreheadf wrote: ↑

Mon Feb 08, 2021 7:33 pm

I got mine out using Gibbs penetrating fluid. I used plumbers putty and built a dam around the neck of the tank so as to make a pool of Gibbs soaking the threads continuously. I smacked with a hammer daily and filled the pool daily. Did this for a week. Took the cap off with a barrel bung wrench. The cap came off in once piece but I did not use it again. Replaced it with a brass one.

If its an original style pot metal cap with the baffle plate under it - its a keeper. Someone might buy it just for the plate to refurbish an original scripted one. May just needs a clean up. as is

Lang's carries a very nice copy of the original 2pc. cap.

What does a wrench used to remove caps from an oil barrel look like?

i had the same problem when I first got mine. Try channel lock plyers held vertical with the sides of the plyers pushing and twisting against the gas cap. also soaking it repeatedly in Gibbs should help.

After three weeks, forum members are still trying to help Bruce, the originator of this thread, get his cap off. We have not heard back from Bruce since the beginning of this thread. Bruce, did you ever get the cap off? If so, how? Jim Patrick

He posted today, it is like 4th one up. Guessing not as he is asking what a bung wrench looks like. Sorry but that cap would have been off 3 weeks ago if were mine. Maybe it has been in the car for over 60 years but at a point somethings need to be replaced like paint. If it does not screw out now, it isn't going to screw back in later.
https://www.google.com/search?client=fi ... ung+wrench

Thank all for the comments. I haven't tried to remove it since the start of these threads. I will use the input received when I get back to working on it.

Oil drum bung wrench.

Hi, Take a vice grip and adjust the jaws upright to catch the tabs and then put a long screw driver or rod and turn it, I have done that several times and always worked. Bob.

Suggest we all save our "breath". The OP hasn't even tried since starting this thread.

You’re right Jerry. Just about very conceivable method of removal has been suggested. Now it is up to him to chose the method and try one when he gets around to it. Good luck, Bruce. Jim Patrick

I got it off!!
I applied "Yield" to it. My grandson and I each used a punch and hammer on the wings and hit at the same time.

Phew! Well done. Thanks for letting us know

Well placed small hammer blows will usually work every time. Glad you finally got it off!
A hammer, pair of pliers, an adjustable wrench and maybe bailing wire are specialty tools every Model T owner ought to own! And oh yes a screwdriver too!
,

Thank you for providing closure on this thread, sometimes we're left hanging!