Exhaust keeps coming loose and carb leak.

Anyone else have this problem an a cure for it?
I cant seem to keep it tight enough to stay put.
Also, is it normal for the float bowl to drip a bit with fuel turned on but not started? It stops once running, i tried adjusting the float level, should i try that again?

Lang’s sells a locking clamp for the tailpipe nut


The gas leak must be solved.
Try and pinpoint the exact source of the leak.
I would certainly try to adjust the float again.
Other sources of the leak might be the Needle and Seat or a crack in the fuel line fitting.

thanks for that, i might make one up now i can see the idea of that one.
I’ll have another go at the carb another day, i’m starting to get a bit fed up with the old thing to be honest, i would like someone who knows what they are talking about to come out for a run in it as every time i try to get it going, i end up breaking down, if i can just get it reliable i could enjoy it.
Anyone out there in West Sussex UK?

Make sure there is plenty of gas in the tank, at minimum 2 gallons. Also make sure there is unrestricted flow to the carburetor. If any modern fuel filter is installed between the gas tank and the carburetor it will cause lots of trouble.

No filters on fuel line, has been blown through to ensure flow, nearly a full tank.

The other common cause of carburetor trouble is the Grose Jet. They often stick closed, or wide open if your gas tank is under the seat.

I saw this some time ago. Haven’t needed to do it yet.

Thanks guys, i’ll have a look to see if i can identify my carb and buy a rebuild kit for it perhaps.
Thanks Paul, thats the sort of thing i was thinking of making up

Based upon your leaking carburetor problem description sounds like the seal between the inlet needle seat and carburetor body is leaking.
This is a common problem with the gasket between the inlet needle and the carburetor base.
The hard fiber inlet needle seat gaskets sold by Model T parts suppliers is entirely too hard and very difficult to obtain a proper seal.
Remove the needle seat, gasket and clean the carburetor body needle seat gasket area very well and use an appropriate gasket.
Perhaps someone will chime in here and let us know the source of a good gasket to solve this problem.
Ron Patterson

I wonder if i tried a bit of grinding paste? anyone tried that? obviously i would need to give it a really good clean out after

The carburetor needs to be fixed and properly. They are very simple and generally reliable, easy to repair. The float level needs to be close to correct. I don’t have the actual specifications, but generally, with the carburetor removed from the car, hold it at eye level. and the float when fully raised should be basically parallel to the upper body. This is of course so long as the carburetor has the correct float to begin with. You should be able to find good pictures on the parts supplier’s online catalogs (Langs is very popular for this use).
When the float is properly adjusted, by whatever means you favor, blow through the inlet valve (your lungs are a better measure than an air compressor!). I usually use a short piece of plastic tubing pressed or clamped onto the fuel line input fitting. Make sure the tubing does not leak. Then again, holding the carburetor at about eye level, with the float hanging down, blow through the tubing. Air should flow easily and you should be able to feel air coming out from the float valve. Take another breath, then again blow, this time slowly lifting the float with your other hand. You should (in your lungs) feel it as the air flow begins to shut off. With only light pressure pushing the float up, you should NOT be able to blow ANY air past that input float valve (this is where the lungs work better than a compressor).
If you can get any air at all past the closed valve (by lung power), that valve must be repaired or replaced.
As for the valves. Personally, I like only the original type. Several different kinds have been offered and used over the years, and many still today. Some with modern material (viton?) (neoprene?) tend to hang up either open or closed, causing a variety of problems. Some modern carburetor valve sets have been adapted, but they tend to be too small and choke the fuel flow at anything above driving very slow. Part of the trouble with all those ideas is that they were designed for modern car carburetors with strong fuel pumps. The gravity feed in a model T cannot push the petrol (gasoline) through the restrictive size or materials of the modern valves.
In theory, one should be able to install a modern electric fuel pump, and regulate the pressure to a balance of enough for high speed (laughable model T high speeds!), without overloading and flooding the carburetor at idle using those modern float valves. The reality is, that about nine times out of ten, such attempts mostly create more problems than they solve. I have always used original float valves myself. New replacement valves like the original type seem to be available at some times, then disappear and not be available for awhile. I don’t know what availability is like at this time.
Advice coming up that I have been told many times over the years that this cannot be done. However, I have done this on most of the model Ts I have had over the past fifty years. Usually (NOT always!), the brass seat that threads into the upper body is okay. Usually an old float needle will wear a ring around where it seats into the brass piece. That worn spot causes the needle to hang up, preventing proper closing (resulting in overflow leaks when stopped, or even sometimes when idling), as well as it may restrict the flow through the inlet a bit when open (causing fuel starvation at those ridiculous model T high speeds!). That float needle can be repaired. They can be carefully ground using a lathe and fine grinder. OR (what I have been told won’t work), pinch a small piece of very fine wet/dry sandpaper in the fingers of one hand, and carefully holding the float needle very straight in the other hand, twist it back and forth, rotating slightly every few twists. If one can hold everything pinched and straight enough, in a few minutes, one can polish the needle to near perfect.
Be aware, a risk model Ts do have, is if you park in your garage, and do not have (or use, or forget to use) a good fuel shut-off valve, the gravity feed from the fuel tank will overfill a carburetor with a faulty float valve and spill petrol onto the floor. That fuel can become explosive, or be set on fire by tools or appliances (like water heaters). I have had several carburetors I have repaired that way, and had them not leak a detectable drop for years. The risk is one to be aware of. Watch for it. Install a good shut-off valve and use it. But don’t let it scare you away from a wonderful hobby.
Model Ts are different than most cars in some unusual ways. The technology is more than a hundred years old. It is different. But once one gets the idea, and makes the proper repairs and adjustments? The cars can become fairly reliable, and a lot of fun. Model T Fords have a unique way of connecting their caretakers to history. They make us understand not only their past, but our own as well. And they help us to understand the world we live in today in better ways than most other interests can. And that “laughable” high speed I mentioned? Not much can beat the pleasure of motoring through the countryside in a century old car at 45 km.

Regarding the exhaust nut, I’ve never had a problem with mine loosening after doing this:

  1. With the engine and exhaust manifold cold, apply nickel Nevr Seez to the threads and tighten the nut as tight as you dare but not so much that you’ll strip the threads.

2.Start the engine and let it run until the manifold is hot. I went on a 15 minute drive.

  1. Tighten the manifold nut snug. DO NOT OVERTIGHTEN WHILE HOT! Note that to get it off again when cold, you might have to heat up the manifold by running the engine again.

I’ve done this once 3 years ago and it’s never been loose since.

Thank you everyone, i will try some of those suggestions, i did try tightening while hot, which has not worked twice now, so i’m going for the metal retainer on a jubilee clip idea for that.
I will take the carb off and re set it again and have a look at the needle to see what shape its in.
I have also found a local old chap who is into Vintage machinery, mainly Model A Ford and Trojans, but he seems pretty clued up, he’s going to come and have a play with it one day soon.
So hopefully, it will be back up and running well again soon.

Read through this post from the MTFCA Forum. Several tips on the needle and seat and a way to make a lead gasket.


Don’t waste your time on one of those accessories! Buy a pack nut wrench instead. While tightening the nut, with a pack nut wrench, you must wiggle the exhaust pipe to get the flange to seat to the manifold. It will never come loose.

You can make a good gasket using a Kleenex box, or of course, just buy actual paper gasket material from an auto part store.

Lead gaskets for float valves: https://www.modeltfordclubofamerica.com/phpBB3/viewtopic.php?f=5&t=1995

If you have a pack nut wrench, and use it properly by rotating the pipe back and forth, it will never come loose.