'25 Dodge carburetor air leak cure

[Pete K.]

Rebuilding a Stewart side-draft carb I had in the pile of parts. The throttle assembly on the carb was so loose, it needed a new butterfly shaft, I thought. Once I removed the bronze throttle bell crank at the top of the carb by tapping out the tapered pin, I noticed that the cast iron upper body had a 1/8" deep under-cut around the brass throttle shaft. It was filled with some dirt, and would allow air to be sucked into the mixture, past the throttle shaft. This will make your car run lousy! I posted a picture of the "fix" here. I unraveled a piece of faucet packing I had lying around in my plumbing parts, packed it into the gap around the shaft, trimmed off a bit and installed the bell crank onto the shaft. It now is air tight and rotates just fine. What a simple repair and remedy for a poor idling Dodge.

[MikeC5]

Great tip Pete. Thanks!

[Guest 1930]

Pete, you may want to submit that to the D.B club for their newsletter. What do you think?

[Pete K.]

Thanks for the kudos, please feel free to post that tip to anybody that may find it useful since I'm not a member of any club. I'm also new to the early Dodge Brothers car and always finding out new things about it here in the "cave". Seasoned Dodge Brothers owners must already know this, I think.---Pete.

[JACK M]

Necessity is the mother of invention !!

Good job.

[MikeC5]

I think water pump packing would work well too (it's probably the safe stuff). I thought Mother was the necessity of invention...

[Pete K.]

I chose the faucet packing because of the ease of separating the twist strands, (3), from each other to get the single strand that would fit in the small area around the throttle butterfly shaft. Auto water pump packing won't work for me because it is more of a solid, sometimes square packing with what looks like some foil embedded with the graphite in the core. Plus the fact I didn't want to cut up a nice piece of water pump packing for an old auto water pump. Remember, this is not holding back hot water, just keeping the ambient air OUT. A single strand with the aid of my trusty, rusty pen knife did the trick. The key here is to get the proper size graphited string, (whereas I lucked out), pack it into opening a couple of turns and pin the bell-crank back on, but YET, not have the shaft so tight it won't turn freely enough. ---Chalk another one up for "DODGE" !!! THEY use a carb that actually has a replaceable packing at a VERY INTEGRAL area determining the final fuel/air mixture!! Owning two '31 Model A's, you can't keep a decent idle or have satisfaction at any speed when those Zenith's have an air leak at the throttle plate shaft. It's brass on cast iron. Sometimes, it's just a real MOTHER.

[MikeC5]

I did the carb shaft re-pack today and she idles smoother for sure. Thanks Pete..

[Pete K.]

Mike, Glad to hear this helped out. These old engines require all the internal vacuum they can muster to run right. It's a very good point you made elsewhere on the forum about evenly tightening the 2 mixing chamber screws and using a new paper gasket there. I hope others starting up old Dodges for the first time temporarily plug off their wiper vacuum line at the vacuum tank until they have verified there are NO vacuum leaks in the wiper system!