Removing A.I.R. tube fittings from manifolds?

[jasonL78]

I was told by an old timer who was a tool and die maker. You can heat up a rusted part and then cool it very quickly with water? I did it with an exhaust pipe and I was able to twist the 2 pipes apart with my hands. So I would think it would work for your manifold also. I guess the theory is when you put the cold water to the hot surface it loosens up the rust? Not sure if you want to give it a try?

Jason

[ORIGLS6]

You might get by with that on steel pipe but I wouldn't try it with cast iron manifolds.

[Keith Tedford]

I've had good luck heating manifolds red hot to get the three exhaust studs out. Of course, these weren't valuable. It's the valuable stuff that cracks. Just don't quench the hot part when finished. We used to bury parts in lime to slow the cooling process. With bolts etc, that are rusted, bottomed out or seized, EZ outs usually aren't of much help and as often as not you see them broken off in the hole. Then you have a real mess on your hands. With patience, you can drill the nut out to tap drill size then fish the remaining thread from the nut out with a scriber or small pointed punch. In most cases, it is better to take the part to someone with the equipment and experience. In a desperate case and a valuable part, you can have the piece EDM'd out.

[John Brown]

[ QUOTE ]
I was told by an old timer who was a tool and die maker. You can heat up a rusted part and then cool it very quickly with water? I did it with an exhaust pipe and I was able to twist the 2 pipes apart with my hands. So I would think it would work for your manifold also. I guess the theory is when you put the cold water to the hot surface it loosens up the rust? Not sure if you want to give it a try?

Jason

[/ QUOTE ]

I've done that many times, and with some pretty valuable manifolds too. Learned the same trick from an old blacksmith. First time I saw him do it I thought the manifold was gonna be toast, but it has worked fine every time I've done it too.

[elonblock]

One of the keys is to heat the manifold evenly until it is red hot. Two people makes the job easier. And then see if you are able to get a bite on any remaining piece of the fitting.

Otherwise as Keith mentioned an EDM machine in the right hands will make short work of removing the fittings and leaving the threads intact.

Elon

[scuncio]

Looks like a couple of these are going to have to be drilled out and retapped. Can anyone provide the correct AIR fitting thread size for a 1968 350 smog manifold?

[acelr8]

1/4 straight pipe thread.Not taper pipe.Jeff