Just lastnight I attempted to fix my exhaust leak coming from the driver side HE. I pulled off the HE and noticed that one of the copper rings looked like it didn't seat well (probably the cause of my exhaust leak). So I removed the old ones in and put two new ones in. This time, I was able to set them in the exhaust port so I could pretty much see that they were sitting flush. Bolted everything back up and now it seems like my exhaust leak is a little louder
How probable is it that my HE is actually leaking from the actual exhaust pipe inside the HE part? I'm tempted to cut a portion of it out just to see if I could find a leak...

what condition are they in? the stock one DO rust, but usually the thinner wrapping gives away much earlier than the pipe part ...

your flanges could be warped ...
Andy

You could take them off and test them with an air compressor.
Block off one end, fill the other.

I would suspect the ends of the HE that bolt to the head are not on the same plane.

Take it off, (BTW, we all have to install these three or four times)
Take a long straight edge of even better a 1/2 in thick piece of flat steel or aluminum...or a countertop.
You may see that the flanges are not the same.
A BIG flat file and a bit of patience can fix that.

When you re-install, do NOT have the muffler attached until you have torqued all the bolts on both HE's head bolts.
Then hang the muffler.

Rich

you may want to check for a pulled exhaust stud. Isn't that a common problem?

If he can tighten them up, then the studs are fine.

I have never been able to get them to seat correctly on the first try, and I have done a few...

I learned to NOT put the muffler on until all the bolts on the head are tightened up. I do hang the rear of the HE off the bracket with a single bolt, but that is loose and just to hold the weight.

I think they must twist over time, so do the head bolts first, then put the muffler on. Then, the muffler connection will leak...and after a few times that will stop.

RIch

They're in decent shape. I did put a straight edge across the two exhaust runners and they weren't that bad off. I did file down a bit to compensate a little. I figured the gasket would seal up the rest. I did torque the head flanges first with the muffler end somewhat supported, then did the muffler flange. I could swear that this time it would be good. Exhaust studs are good. I helicoiled and replaced one the last time I had the HE's out...
I was thinking...not knowing the history of my HE's, could it be possible that the flanges have been filed/machined down multiple times already, decreasing the length of the flange to the mounting hoops, and that the mounting hoops are bottoming out on the studs when i torque them down, thus not creating a great seal at the head even with the copper o-ring?

thanks for all the responses

yup, the hoops also get bent and wont seat due to alignment.

You can use some machinist dye on the head and around the studs .
Put the HE on there and wiggle it around, it will rub off the dye that it touches.

also, prior to putting it on for the last time, anneal the copper, it makes them a bit softer to crush them in place.

Rich

If I were looking for a leak in the "tubes" I would go to the hardware store, buy a couple of large corks, plug one of ends and fill the other end with water. If the water level holds, your "tubes" are OK. Otherwise, you have a leak.

If you think a stud is bottoming out due to a bent mounting strap, you could (at least temporarily) stack a washer or two on the stud.

Those copper gaskets aren't going to compensate for HE surface irregularities very much.

I always re-anneal copper gaskets before install, even new ones. It softens the copper. I only have to mount them once. The only HE I've had leak was due to a pulled stud.

if the he is leaking in the casing you'll hear it with a piece of garden hose stuck in the warm air outlet while the engine is running. the hose also works well for pin pointing which he to head connection is leaking. the tightening sequence is sort of crutial. if you don't, try it this way. get all the nuts started. while pushing up on the he start tightening in a x pattern. once the all nuts are lightly seated (the he will not rock around at this point) you take the torque value up, still in the x pattern, with your torque wrench in stages. i use 5# increments. just fully tightening one nut and moving on to the next can build in a bind/leak that won't ever seal. if you continue to tighten you'll prob just strip a stud out of the head.