The other day I was looking at a rh exhaust manifold that I have and noticed the slightest amout of daylight showing at the top of the manifold where the choke stove tube is, to see it I looked from the bottom side of the manifold up when holding it to the light, so it is coming from in between the tube and the casting wich would cause a small exhaust leak would anyone have any tips on how to fix this, my first thought was some jb weld around the tube from the inside of the manifold but I'm not sure if it would withstand the high temp of the exhaust at that point.
Exhaust manifold choke stove tube leak
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Re: Exhaust manifold choke stove tube leak
The other day I was looking at a rh exhaust manifold that I have and noticed the slightest amout of daylight showing at the top of the manifold where the choke stove tube is, to see it I looked from the bottom side of the manifold up when holding it to the light, so it is coming from in between the tube and the casting wich would cause a small exhaust leak would anyone have any tips on how to fix this, my first thought was some jb weld around the tube from the inside of the manifold but I'm not sure if it would withstand the high temp of the exhaust at that point.
Jim------
Do what Mike says. In any event, you can't really use JB Weld on an exhaust manifold. JB Weld is GREAT stuff but, unfortunately, not for exhaust manifolds.
If the new tube does not solve the leak problem, you could probably braze the hole and re-drill. This is not a high strength situation so brazing should work fine and is compatible with cast iron.In Appreciation of John Hinckley- Top
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Re: Exhaust manifold choke stove tube leak
Jim-----
The tubes are GM-discontinued. However, I believe they are available from the Corvette reproduction vendors.In Appreciation of John Hinckley- Top
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Re: Exhaust manifold choke stove tube leak
That hole is drilled straight through the top and bottom of the casting in one operation, and the tube itself is straight, just like the hole.- Top
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Re: Exhaust manifold choke stove tube leak
John------
That's what I thought, too. I've never seen a curved tube but it's been so long since I've been involved with one of these things I couldn't say one way or the other.In Appreciation of John Hinckley- Top
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- Top
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Re: Exhaust manifold choke stove tube leak
The problem encountered when I installed a replacement tube in my 2 1/2" manifold is that one end of the replacement tube is interference fit and the other end is not. How else do you install a replacement tube. I used some J&B weld from the inside to seal the top hole and have never had a problem.
I don't know how these tubes were originally installed unless they had a tool to expand the tube end after inserted into the manifold. I know for a fact it was staked at the bottom.- Top
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Re: Exhaust manifold choke stove tube leak
The problem encountered when I installed a replacement tube in my 2 1/2" manifold is that one end of the replacement tube is interference fit and the other end is not. How else do you install a replacement tube. I used some J&B weld from the inside to seal the top hole and have never had a problem.
I don't know how these tubes were originally installed unless they had a tool to expand the tube end after inserted into the manifold. I know for a fact it was staked at the bottom.JR- Top
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Re: Exhaust manifold choke stove tube leak
The problem encountered when I installed a replacement tube in my 2 1/2" manifold is that one end of the replacement tube is interference fit and the other end is not. How else do you install a replacement tube. I used some J&B weld from the inside to seal the top hole and have never had a problem.
I don't know how these tubes were originally installed unless they had a tool to expand the tube end after inserted into the manifold. I know for a fact it was staked at the bottom.
Timothy-----
I think you were lucky with the JB Weld. JB Weld is specifically not recommended for use on exhaust manifolds or for any application in which the temperature continually exceeds 500 degrees F.In Appreciation of John Hinckley- Top
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Re: Exhaust manifold choke stove tube leak
In order from left to right cc, lic & paragon sell the choke stove tube and all three are different tubes, the one in mine now looks like the one from paragon and the cc one looks like it is only friction fit on one end.JR- Top
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Re: Exhaust manifold choke stove tube leak
If your tube is now bent, it is probably due to fail by burning through soon. Tubes that are pressed into sort of an "X" pattern were those used on earlier Chevy V8's, according to what I can best figure. I recall replacing them on 57 Chevies and they were pinched into that "X" shape to (I assume) slow down the flow of air and ensure it got hot enough (I once used the same principal on an external aluminum tube wrapped around headers by pinching with a vice grips). I suspect, but can not prove or get consenses on, these tubes were used on engines that did not have a fresh air connection to the carb for a filtered air source, rather they drew air from the ambient air existing below the manifold which could, on some winter days, be darn cold.
I believe the round tubes are associated with the fresh air type systems beginning in the early 60's. I think if you drive it in from the bottom (the top being the press fit end) you can probably (on purpose or otherwise) "swedge it" into the bottom end to seal it, then "stake it" or roll it in.
Stu Fox- Top
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