Manfold exhaust nut

Is there an easy way of removing the exhaust nut from the manifold. There is a special wrench that could be purchased but I wondered if there is another way. I think I just used a pipe wrench when I installed it but I have always had some leakage. It may be very difficult to remove with rusting on over many years.

The proper wrench is necessary. My grandfather made this one many decades ago. It’s necessary to heat the manifold before the nut can be turned.

That was clever of him. It must be bent at an angle near the jaw. The engine would need to be running to get the manifold hot enough I would imagine. Thanks for the reply.

It was not his idea. He copied a KR Wilson wrench the only way he could - using a band saw and a file.

Normally you heat the manifold using the engine. If the engine doesn’t run you can use a torch.

I have always had a problem with exhaust leakage so I thought maybe I could install a new gasket. It may be more work than it is worth.

There’s not a gasket between the nut and the pipe if your T is from 1914 - 27. The earlier T’s have asbestos string wrapped around the pipe before the nut is tightened.

That’s interesting. I am sure I bought something years ago at Mac Auto parts. No idea what it could have been.

First off if the pack nut is reluctant to turn don’t put too much muscle on whatever wrench you use. It’s fairly easy to snap the end of the manifold off. If bad comes to worst the repop manifolds all the vendors have are a perfect fit.

Faced with a pack nut firmly rusted in place I’ve had good luck with generous applications of a penetrating oil of choice over the span of a day or more. First trying to tighten the pack nut can be beneficial to initially break the nut loose, and then work it back and forth, again with generous doses of penetrating oil, to hopefully remove it successfully.

As for the leakage issue over the years metal from the entire manifold is lost to oxidation and such. This is fairly critical to sealing the exhaust pipe to the manifold in the thread area. One trick they used back in the day was to take a suitable length of stranded copper wire and wrap some strands around the thread grooves to fill the gap(s) left by the erosion of metal in the area. It’s a trial and error process to get a suitable amount of copper involved. To keep the copper in place they would use a glob of thick axle grease, thicker the better. It’ll smoke some at first but the grease soon burns away. Another stunt I’ve used several times is to take the pack nut, clamp it in a vise and using one hacksaw blade for thickness make a cut perpendicular to the threads. Then re-clamp it in the vise so as to close the gap. File a fillet groove and braze the ends together. I’m not a welder nor have I got torches, etc. so I farmed the job out to a professional.

At reassembly I’ve gone two ways; both seem to be equally effective. One is to generously coat the threads with an anti-seize of choice. The other I copied on the advice from a mechanic from the very old school. I got hold of some powdered graphite and made a thick paste with it using thick axle grease and giving the threads a generous application. Oil works too, the thicker the paste the better. Like the anti-seize, it burns off quickly. I may be overthinking here, bu once or twice a year I loosen the pack nut a turn or two and retighten all with the engine good and warmed up to operating temperature.

You mentioned a purchase from MAC’s. As Auto_Inn says there’s not likely a gasket unless you have a very early T Model. Model A exhaust pipes attach to the manifold in a somewhat similar way as the Ts, but with a two piece clamp rather than a pack nut. There was available an asbestos wrap that sometimes did the trick to stifle an exhaust leak. There is also something in a tube you can smear around the flange area sometimes to good effect.

Hope all this is of some help. If you have any questions I’ll be very glad to have a go at answering them.

Regards, Tom in Taylor Mill, KY 41015

Thanks. That is a great explanation. I had heard about the possibility of snapping the end off.

When I don’t have a proper pack nut wrench, I use a giant pair of channel locks, but the proper wrench is definitely the way to go. A few special cases:

If it hasn’t been off in years, all the old tricks apply - WD-40, etc.

Don’t try to remove it when hot - let the manifold cool for several hours. Iron and brass and steel expand and contract at different rates. I’ve never heard of a manifold breaking, but did mangle the end of an exhaust pipe while trying to force an exhaust nut from a hot manifold.

When re-installing, I haven’t used any gasket or sealant. You will want to re-tighten the nut after the engine has run a bit. I also installed a Texas T Parts clamp that keeps the nut from loosening on it’s own (Bird Haven Vintage Auto Supply), after repeated experiences having the the exhaust come loose while driving even after retightening.

See you on the road!

Thank you - most helpful