Exhaust manifold to muffler connection question

[30coupeguy]

After I reinstalled the engine the connection between the two leaks. My first attempt to stop the leak was with a permatex type hi-temp sealer. designed for this type application. I applied it liberarly on both sides of the connection and a lot around both, under the clamp. This worked great until I drove the car. The sealant liquified and mostly ran out and down the muffler pipe.
When I removed the engine this connection had a hard sealant that looked like old furnace cement. It came out in pieces as I recall.

I bought some sealer from the model A parts catalog but have not yet tried it as I am a little dubious about this approach now. Also, I purchased the A-5234 Exhaust sleeve and a copper gasket.

I have not made sense out of these parts yet. If the smaller diameter of the sleeve is placed in the muffler end, the other end does not fit into the manifold. It also has a wide gap between the two. Does this require some modification?

The copper gasket does fit in the muffler pipe but not the manifold. Is this how it is supposed to work? If this is the way to go, shoud I use the "official" gasket sealer as well?

Any suggestions will be greatly appreciated.
Thanks all
Burt

[AL in NY]

30coupeguy: made sure you are installing the clamp in the right orientation. If you look closely at the clamp, it's V-shaped, but the "V" is not centered in the middle of the clamp(ie top to bottom). I believe the larger part of the "V" goes to the manifold side of the joint.

I've also used a product by VeraChem- Exhaust System Joint and Crack Sealer. It comes in a 5oz tube and it has the texture of dry clay. You place it around the joint, connect up the muffler and tighten up the clamp. The excess sealer oozes out, and you wipe it off. Start up the engine and heat the sealer and it dries hard. The pipes come apart easily because the sealer breaks apart and doesn't really form a bound with the two pipes. It just hardens and fills in any gaps.

[montanafordman]

You really shouldn't need sealer, or very little if any. The biggest thing i have found when installing the clamp is to tighten the two bolts evenly, then give the clamp a rap with a hammer and you will be able to tighten it some more.

[Bruce,Upstate NY]

First hold the pipe up to the manifold to see if they line up in a straight line. As manifolds warp the flange moves forward. Remove the exhaust pipe, stick a pipe down it and bend until it matches the angle of the manifold. It may take a few tries. With the rear clamp holding up the tailpipe I put a jack ahead of the muffler and put upward pressure on it. With a torch I heat the pipe flange until the flanges mate well. Put the clamp on with the longer angle on the bottom..

[Mitch//pa]

throw the copper gasket as far as you can.
just use the sleeve with no goop and youll be good
make sure the muffler clamp is on right as mentioned
and no the sleeve does not cause an exhaust restriction

[Joe K]

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I think the two posts above mostly covered it. Especially the part about throwing the copper gasket. (heh)

As to the connection between the two, think flare tubing.

The manifold taper should be uniform and fairly even (cone) and not really worn into a segment of a sphere, which it is wont to do.

The pipe flare shold be uniform and fairly matching the cone: without the clamp you can put the two together and you should see them touch all the way around. And maybe catch a little bit of a spherical action as you wiggle the tube on the manifold. But only a little.

You can change the flare of the tube either with a flaring tool (can be borrowed from a muffler shop or bring the pipe there) or a split mandrel can be made of hardwood on a lathe, clamped around the pipe and a ball pein hammer used to work the taper "more tapered." (or less depending on your mandrel.)

Some do this sans mandrel and using only their eye for guidance with the pipe held between their legs and application of the pein hammer to the inside of the tube directly. If you've a REALLY good eye you can do this all the way around and make a flare from virgin tube.

And it wouldn't hurt to heat up the flare to cherry red to anneal the metal before making any drastic changes - this so you don't make a crack or split on embrittled (work hardened) metal.

Hope this helps. I went through similar looking for leakage from what I thought was around the flare. Using an oil can and dropping oil on the exhaust manifold I found hairline cracks ON THE MANIFOLD ITSELF - which I promptly replaced and solved the exhaust leak immediately.

Funny, breaking up that manifold to go in the scrap barrel I just TOUCHED it with the hammer and it fell into at least four pieces. I wonder how it had held together while on the car?

Good luck.

Joe K

[Ron/IA]

http://www.amuffler.com/content/otherproducts.htm

The above listed address shows the best clamp I have ever used. I have tried all clamps, sealants, and gaskets known to man, and none have ever worked for me.

The best gasket I ever used was one I made from folded aluminum foil. It lasted the longest.

I currently use the above clamp with the above mention tube available from several vendors; along with careful bending and aligning the exhaust pipe to the manifold. You need to get as perfect a fit as possible between the flanges of the pipe and manifold. Nothing I have tried has worked as good as this combination.

[CarlG]

I took mine to a muffler shop to have them re-form the flange so that it would fit better. They said that due to it being heat hardned, it was too brittle to re-form. So they cut the old one off and made me a new one and welded it on. No leaks since then. And I have the Aires clamp.

[1crosscut]

I use the high temp muffler sealant paste. The trick that did it for me is to use a floor jack to lift the muffler into place against the manifold making adjustments to get things lined up just right. THEN carefully let the jack down just enough to put a layer of the muffler sealant on the female side of the muffler. Bring the muffler back into place with the jack and install the muffler clamp. If things move out of line start over and get it lined up right. Done right it should last a long time.
Dave

[Marshall V. Daut]

I have been following the procedure that "1crosscut" described for years now. It's the only way I can get the tailpipe to line up and STAY lined up while tightening the clamp. For years there was nothing available but really lousy, wimpy clamps that would not/could not hold the tailpipe properly. Leaks always resulted. These were J.C. Whitney/Rick's Antique Auto off-shore garbage that are still around in great numbers. Unless you have an original clamp or have RECENTLY bought a new one from a major Model A vendor, toss it and purchase a new one. They are much better formed to hold the two pieces in place. If you try to use a skimpy clamp from the 1970's-1990's, it's an exercise in futility. I am very impressed with the newer clamps design, strength and looks. Every one I have installed has fixed a frustrating leak on mine and customers' cars. And do use the sealer available from the vendors, not what Pep Boys or O'Reilly's or Autozone sells. Junk! The red stuff sold by the Model A vendors is red and easy to apply. It also separates easily, should the occasion arise.
In sum - (1) use a floor jack as "1crosscut" described; (2) ensure the clamp is correct; (3) and use the red sealant in the copper-colored tube. You may also have to loosen the tailpipe clamp in the rear in order to get the pipe flange up front to align properly vis-a-vis the manifold flange. It CAN be done and leaks eliminated. If, however, after following these procedures you still have a leak, I'd check the manifold for cracks around back, a very common occurrence. Also be sure the manifold isn't dropping at #4 port, a sure exhaust leak maker.
Marshall