Fuel gauge

[vintageair]

Since I bought my Champ last year I've been flying around with this fuel gauge that is basically a three inch black hole - can't see anything. Anyway it's annual time so I decided to "fix" it. I drained the tank and unscrewed that knurled ring but what do I do now? How do you get these things apart and are there any parts available? I figured I just needed a new gasket and clean up the glass, it's black because of seepage and 100LL dye.

BTW, this is a converted FC so it has wing tanks, gauge is in the right wing root. I've been fine without it because I use a dipstick and a clock for fuel management but it would be nice to have the gauge working in case there was something wrong like fuel venting overboard. I could look at the gauge and ask "Why is it doing that?"

[jepropst]

I'm by no means an expert on the fuel gauges, but I've had a number of opportunities working on them. I attempted to attach a photo showing the various parts of the Ford gauges. Replacement gauges and parts are available from Wag and other antique Ford parts sites.
You can remove the gauge by loosening the outer nut. A very large wrench or plumber pliers work. If you need to remove the inner nut, I would recommend doing so after the gauge has been removed. You will need something square shaped to fit the inner nut to remove it. I found that one end of a Rigid plumbing tool fits. Removing the guage is the easy part. The tough part is getting the replaced gauge to not leak. I found that tite-seal works good. Concerning your wing tank, you have very limited space for working on the gauge with the wing mounted. If possible, consider repairing the gauge when the wing is removed. After working on the gauge you need to fill the tank completely full and wait a day if possible to make sure the gauge doesn't leak. Gas has a way of leaking no matter have careful you are at assembling the gauge. If you must, you can work on the wing gauge in place but you probalby should remove the wing gap seals. (sorry about the size of the attached photo but I haven't figured out how to make it smaller).

[Captgrumps]

You can get the model A fuel guage tool from any model A Ford parts place--I don't rely on the original Aeronca guage, I have installed a Piper J-3 wire guage in place of the filler cap from Univair--it has a molded float. Calibrated it, marked it. I keep a regualr cap in case the airplane has to sit out. I don't even trust the Model A guage in my Model A.

Doug

[flyingfool]

I just got done working on my Chiefs aux tank. THat gauge is different than the main tank on the champ or chief.

Here below are the two model A sites that deal with the gauges. I dealt with Mikes and the service and turn around was quick and everything arrived correct. The Mikes site also on one of the listings for parts lists the proper order to assemble the gauge.

I would if I were you tempted to get a whole new inner and outer rings. Along with the star tool. This eliminates the knurled nut and allows more control to tighten the gauge assembly up.

Please be aware. The "glass" lens is NOT, repeat NOT glass. It is some sort of plastic or lexan or something. So if you use MEK or Acetone or something to clean the lens, it may fog it over and make it nearly impossible to not clean it up or ruin it. Or simply buy a new lens as all of this stuff is pretty cheap. I personally do not like the little oval window plate. Makes the hole too small for me to see. My gauge also is silver with just a stamping showing 1/4, 1/2 etc. There is no paint or anything. So there is not much contrast and this makes it hard to read. If yours is similar you may want to try to paint the stamped numbers to help make it easier to read. I do not know what kind of paint would be durable in the fuel environment. But maybe someone here would know this.

I know if I knew the proper paint I'd take my gauge out and do this modification over the winter. I'm relatively short and in my chief I find it nearly impossible to see the gauge. I have to nearly kneel up on the seat and lean over the dash board. I use a calibrated dipstick and my watch for fuel use as my primary means of fuel level.

[vintageair]

Thanks for the replies.

Looking at what I've got, I can't figure out how to get it apart. The lens (you're right, it's not glass) is just recessed in there below the threads that the knurled outer ring screwed into. There's nothing else to unscrew or grab onto. I really don't want to rip this apart and end up grounded or have to pull the wing so I might just let it go.

I'll get a picture tomorrow or Saturday and post it.

[Roger Anderson]

I personally do not like the little oval window plate. Makes the hole too small for me to see. My gauge also is silver with just a stamping showing 1/4, 1/2 etc. There is no paint or anything. So there is not much contrast and this makes it hard to read. If yours is similar you may want to try to paint the stamped numbers to help make it easier to read. I do not know what kind of paint would be durable in the fuel environment. But maybe someone here would know this.

I know if I knew the proper paint I'd take my gauge out and do this modification over the winter. I'm relatively short and in my chief I find it nearly impossible to see the gauge. I have to nearly kneel up on the seat and lean over the dash board. I use a calibrated dipstick and my watch for fuel use as my primary means of fuel level.

Me too, on all of the above. Being short, I removed the oval window plate and magnifier. I can much better see the indications now. Like you, some paint on the numbers would help though.

[vintageair]

Finally got around to getting it apart and took some pictures. It just took some prying and coaxing. This isn't exactly a delicate piece of instrumentation, it can take quite a bit of abuse.

All I need now is a source for the lens and gaskets. Diameter is about 1.85 inches (1 7/8 or 1 13/16 or 1 27/32???)

[vintageair]

Update:

After some poking around and doing some research I've determined that what I have is NOT a Ford Model A gauge so those rebuild parts won't work for me. What I do have is very basic however so all I really need is a lens of approximately 1 7/8 inch diameter and about 0.1 inch thickness. Any thicker would be a problem since the threaded recess is not that deep. I also think a glass lens would probably be a problem since I really will have to tighten that knurled ring pretty good to make sure it doesn't leak and that would put a lot of pressure on a glass lens - probably crack it.

So I'm looking for a suitable lens - almost looks the exact size of a standard flashlight but it's just a bit smaller. I can make the cork gaskets myself and from the looks of this thing I don't think I would want to use any glue or sealant since it's probably impossible to completely stop all seepage and it may be just a regular annual thing to pull it apart, clean it up and install new gaskets.

Another option I have is to just simply polish up the lens I have.

Anyway, it's the only thing left on this annual so I want to get it done and go flying. The weather is starting to get good again, those hot summer dog days with molar jarring thermals are close to being just an old memory and dusk is starting to occur before my bedtime.

[jepropst]

While you have your gauge removed, you may want to measure the thread diameter and thread pitch on the knurled nut that holds your gauge into the tank. I can vaguely recall from memory that the Ford gauge units have a 1-7/8" diameter thread and I think the thread pitch may be 18 threads per inch. I have some spare gauge nuts at my hangar and can measure them tomorrow. Also mesure the depth of the threads on the boss on the tank. From your pictures I'm guessing that a Ford gauge may fit into your tank. Complete new Ford units are available from a number of sources at relatively reasonable prices. Also, for what little it might be worth, my experience has been that dry cork and composite gaskets often do not seal gasoline very well. I have personally had good luck with both Tite-seal and Permatex B (non-hardening) sealers. If you post your name and phone number I can call you with the thread info.

[jepropst]

I checked a couple outer nuts that I have for a Ford gauge. The threads are a nominal 1-7/8" diameter X 20 Threads per inch. I say nominal because one of the nuts measured 1.847" and the other measured 1.856". Both nuts are new out of the box. What I found that was when I installed the gauges on new tanks with new bosses, the nut was so loose that it would skip threads when being tightened. I solved my problem by making new brass nuts threaded to the correct tolerances for the hub (ie slightly under 1.875).
By just eyeballing the outer nut, I would guess that the hub on the tank should have the shoulder recessed at least 3/8". If someone has a tank available they may measure the depth of the hub to verify or correct this dimension.
I found a box for a complete gauge. It is marked with "Mac's antique auto parts" and has a part number A-9312-D. I also have a package marked rebuild kit and is is also from Mac's and has the part number A-9320-S. You can Google Mac's antique auto parts to get to their website. Contact me if you need more info. If you call Bill Pancake on 304-788-7897 he may be able to provide you with additional info on the gauge that you currently have.

[vintageair]

Thanks for the info John. As you can see what I have is about 4 or 5 inner threads, not much room for a whole lot of stuff. So I think I'm just going to replace and/or replicate the original equipment. If it leaks we'll go from there but my take is that it's just one of those old old world things that requires regular maintenance.

[shorty]

Mikes-A-Fordable has all the parts you need to make your fuel gauge good as new.
He also sells the proper tools to service it.

[vintageair]

Update: I had a new lens made and put it all together with a new cork gasket that I made myself. It did leak a little bit, just some weeping so I ordered a tube of EZ-turn and put it on the threads. That seems to have done the trick, it's been leak free for about a week now.