MTFCA Forum

Hi friends! My father and I are getting ready to replace the gas tank on my 1922 Center Door. I have a decent amount of experience working with modern automobiles, and have learned the hard way enough times that it's better to just follow the directions in the repair manual to a "T" than to freelance. That said, I've found the amount of technical documentation for the Model T is not quite as robust as one might expect to find for a modern car, which makes me a bit weary because experience is not something I have to guide me yet and I would like to get it right the first time

For those who have replaced their own gas tank, or performed work on the fuel line and/or sediment bulb: what are some best practices or words of advice that you can offer us before we embark on this journey? I'm most concerned about achieving a good seal on the fuel line connections, so I don't have any gasoline leaking out of the car but also don't break anything and have to wait 1-2 weeks for a new part(s) in order to finish the job. Are there any resources I can consult for torque specifications on the connection of the sediment bulb to the tank? Should I be sealing the threads with anything? Are the OE felt pack nuts for the fuel line really the best for the job, or is there a modern equivalent that can be easily adapted to the task?

Thanks in advance for any advice you may have to order. BY THE WAY, for those looking to order a new replacement fuel tank, but are finding ridiculous back-orders from most of the online retailers, after calling enough shops I was able to purchase one from S&J Antique Auto Parts. I ordered the new (reproduction, obviously) tank on April 17th and it was delivered yesterday, exactly 5 weeks later; much better than the 6+ lead times being advertised by Snyder's and Lang's!

Dan

I recently went through some of what you're describing, with my '23 center door. I am also a T noob.

I didn't remove my sediment bulb or tank, but I did replace the screen and lead gasket. Soldering the screen was an interesting challenge. I posted a thread you can find if you search.

My car had a copper fuel line with incorrect adapters on the sediment bulb fuel outlet, to a compression fitting. I ordered the correct nut (pack nut ) from Lang's, and used it with the existing piece of copper line and brass compression ferrule. Not technically correct, but it works and doesn't leak.

I'm waiting on a carburetor, and working through a misfire issue right now. After that is over I am going to replace the copper with a steel line

I believe most people use the yellow tape on the sediment bulb to tank connection. The fuel line uses felt or neoprene to seal it. Best to not use compression fittings. Also a good idea to put a shutoff valve by the carburetor. Dont forget to flush the sediment bulb at least once a year.

All good info.

Re the sediment bulb, no torque, those are tapered pipe threads! Results for me are with Permatex sealer for the threads, gas resistant, all pipe threads use some dope in plumbing, you'll want a gas resistant version.

If the bulb is old, you have to take it apart and clean or replace the screen in the large nut. Tricky to remove, heat the iron around the nut and the lever arm with a torch, then place the assembly in the freezer. The brass will shrink from the iron and you'll remove the nut and lever without damage.

Or, replace with a new reproduction bulb, they are nice.

For the gas line, use steel tubing, auto store, brake line. Bend and then cut to fit. Cut so you have a bit of steel line going into the inlet elbow too, it secures best that way, then tighten the pack nut to compress. Use the factory pack nut, but substitute neoprene gas line segment for the factory felt. Then the gas nut will compress the neoprene gasket and no leaks, and no worry of fracture from compression fittings. The T really shakes and rolls, you'll find the factory pieces are made to do the job.

Top: Ford felt
Center: Poor replacement, copper tubing and compression ferrule used in a Ford pack nut, note the tubing is stressed already.
Bottom: Ford pack nut, steel line, and modern gas line neoprene segment cut to replace the Ford felt.
And this copper line with compression fitting cracked right at the end of the compression fitting, on a T on tour, causing owner some grief.



Permatex on threads of sediment bulb only.

Thanks all for the replies. Very useful info! I assumed the bulb would likely be corroded, so I've already ordered a reproduction bulb, as well as replacement bulb screen, lead gasket, as well as replacement pack nuts and felt.

DanTreace- What is the application of the elbow? Is that in case the outlet of the bulb parks away from the engine when tight? Also, any idea what side of neoprene gas line fits over the steel line?

Daniel

If I understand the question, the elbow is part of the carb. That is the inlet of the gas to the carb. The gas line is mounted to the elbow with the pack nut.

For the segments of fuel line to replace the old time felt, you may have to determine that with what steel brake line you get. I used 1/4" size steel brake line.

Lang's makes the neoprene fuel line packing, in the online catalog or order # 2913N. I use their part because it always fits fine, tight push over the 1/4" line and when the pack nut chamber closes on the neoprene, it expands and seals great. Can be reused and reused when you pull the carb, and have to remove the gas line.

The reason I cut the line a bit long is to have it engage into the elbow, then hold the line in place, and then tighten the pack nut, squeezing the neoprene. When you have to remove the gas line, remove the nut, and pull out the gas line from inside the carb elbow, the line will flex enough for that.

Thanks Dan, I appreciate the insight. I've ordered the neoprene packings from Lang's, and intend to use them instead of the felt ones. Did you utilize any special tools to work the steel gas (brake) line into the correct shape? I'm sensitive to the possibility that in the process of uncoiling it and routing it, it may kink, bringing me back to square one. I see there are straightening and bending tools for steel brake tubing on the market, but am not sure how many one time use tools I want to invest in to do this job...

Daniel


The brake line is rather soft, so didn't need much bending tools, as the bends for the open car chassis I'm used to plumbing are fairly easy with bare hands. You do need a tubing cutter to make clean ends.

Laid out the bending guide from a package insert that comes with Lang's straight length of tubing, so I had a copy and followed it by marking on my bench the bends needed. Then shaped to the layout on the bench top with my roll of store bought brake line tubing.

Your sedan tank under the driver's seat would use a bit of different bends, as shown in Ford Service Bulletin.

Dan Treace- Once again, THANK YOU. Does anyone have photos depicting the fuel line routing for a sedan? Should I be insulating the line with anything where it comes closest to the exhaust pipe?

The proper routing is illustrated in the center diagram that Dan posted. If'n I get time today, I'll roll under our '19 Centerdoor and take a photo for you.

With a photo from Steve, you'll have little trouble routing.

Here is open car, factory route, the gas line tucks under the exhaust pipe for only a very short length, no need to wrap.

Plenty of cooling air travels thru those spaces when on the road.



Some pass the gas line thru the notch in the wood block inside the frame rail and crankcase arm, but for the later N-H carb, going along the outside of the crankcase arm works well too. Is important to use the gas line clamp at the front bolt for the the control shaft. Keeps the line in place, away from exhaust pipe, and strain on the fittings at both ends.