Tricks and rules for exhaust system work? taking apart etc

e9999

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Don't know anything about exhaust work.

Was looking at my exhaust system the other day after some Seafoam revealed a leak at a gasket (that thankfully sealed itself in a few minutes -or maybe dried out to be less noticeable).
But I tried to tighten the nuts and they would not move at all.

So, in general, what's with bolts and nuts on exhaust pipes and cats? These all look pretty frozen in place, more rusted than the rest of the truck, and have been exposed to high temps. The ones on my O2 sensor look like they have been rounded off, which suggests major stuck on.
How does one remove exhaust system nuts and bolts most easily? Cold, hot, lube, Kroil, nut splitter, grinder?

General rules or tricks?
 
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I don't think I've experienced too much worse than removing the hot end of a turbo off a cast iron manifold. Liberal lubrication, good six sided sockets, and a 2' breaker bar are about your best bets. Using a torch to loosen up the nut can also help.
 

e9999

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best to do these hot or cold?
 
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e9999 said:
best to do these hot or cold?
exhaust system cold so you have the option of torching the nut if you need to.

Edit: besides, you wont burn yourself on the piping and it won't stay hot for long anyway. :)
 
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Eric, another point is that the OEM nuts used have a metal "locking" lip that fxns just like the nylon lock nut inserts but obviously don't melt at high temp. These work really well at not allowing the nut to back of and become loose from all the vibration and heating/cooling cycles that an exhaust sees. But they work a little too well when it is time to remove them. I carried around a spray can of PB Blaster for nearly a month, spraying down the bolts right before I got in the truck and after it had run for a while and then at night. It still was a bear to get it apart. My biggest mistake was using a vise-grip wrench. It compressed the nut onto the bolt stud and actually made it harder to take off. If you find a socket doesn't work, do yourself a favor and go get a set of those reverse spiral nut removers from Sears or the equivalent. I tapped one of those onto the worst nuts to "seat" it as far down on the nut as possible and it came right off.
 
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e9999,

I recently replaced the main muffler and connecting midpipe as well as the downstream O2 sensor on my 1997 LX450. I had to cut every bolt with a Dremel due to the rust. My O2 sensor studs were rounded also and in fact, one had broken off completely which precipitated all of the exhaust work.

Good Luck
 
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The very best thing you can do is to soak the fasteners liberally with a penetrating oil nightly for a few days before you work on the exhaust. That alone will make a world of difference.

A sawzall is your best friend when the nuts won't budge or they are stripped - you can have a pipe cut in less than 60 seconds with a powersaw and a metal cutting blade. I never regret investing in one. I don't use it very often, but when I need it, I NEED it.

Here's mine:

Makita reciprocating saw

If you decide to get a saw, check out Home Depot.

John
 
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