stuck manifold flange bolt

[horsemel]

When I replaced my hump hose a month or so ago, the riser swiveles in the flange where it enters the manifold.  There was some discussion of this on the message board.  Tjhis weekend I decided to remove the flange from the maniforld in order to tighten the riser in the flange.  I cannot get the bottom nut loose from the threaded stud  The top two are hex head bolts.  I followed the advice from the discussion and myself and a dock neighbor could not get the bolt loose.  We have soaked it with penetrating oil and heated the engine.  Another fellow who used to restore antique cars said that to soak the nut with penetrant whenever I am at the boat, run the engine and soak it again as it cools.  He saiys that it eventually will free it, but might take 3-5 weeks to do so.  Is it safe to operate the engine with a little exhaust bleeding around the riser at the flange?  It seeems to be putting out a minimum of soot and is a little noisier than usual, but other than that seems to be fine.  If nobody is down below when we run the engine, the problem with CO should be minimal.  I am sure it has been like this for a while.  Also, any other suggestions on how to get the nut off the stud would be appreciated.  I don't like the thought of just a few more weeks in the season and not being able to use the boat.
Mark Mueller

[Stu Jackson]

Mark, it took me a full week, every day, to get that bottom nut off.  I did it in May 2008.  I think I posted some info on it under "blow by."  Don't get the penetrant anywhere near the transmission seal. 

Here's the link:  http://c34.org/bbs/index.php/topic,4273.0.html

I found it in a search under "exhaust riser" with my name.

[Terry Forshier]

why don't you put the other 2 nuts on the bolts, use the boat and just work on the stuck one whenever you have the opportunity. Just keep working on it. I was able to get mine off pretty easy using a socket with leverage. Is the riser lose or the flange?. If it is just the riser, try putting some of the muffler sealer around the opening, squeeze it in, then wrap it and let it dry. That should keep the seepage out. (I used auto muffler maniflod wrap)
A hard job to get your hands around I know. Terry

[Gary]

Hi Mark,

If you have not, could I suggest that you add a Carbon Monoxide Detector to your inventory?  Since CO is not detectable by smell and is so fatal it would be good to protect yourself while you work on the frozen exhaust flange, or while motoring, even if you are not in the main cabin.

They are available at West Marine and look like a standard smoke detector in your home. I think mine was around $30 at a discount store.

Mine is located in the aft cabin as I suspect most CO will accumulate there first.

Gary

[Ken Juul]

Carbon Monoxide (CO) is heavier than air, it will sink to the bilge and gradually fill the boat up forcing the O2 out.  The CO monitor should be placed low to detect any CO before it gets high enough to be a hazard.

[Stu Jackson]

From my August 2008 Secretary's Report in Mainsheet:

In our constant efforts to keep up with the demands of our almost 22 year old boat, and celebrating our tenth year with Aquavite, we tackled the exhaust riser blow-by we’d been experiencing ever since I made the mistake of having someone else work on our boat.  Within a year after the “mechanic” replaced our exhaust riser in 2003 we began experiencing a sooty exhaust over the heat exchanger.  Suspecting that the specified muffler patch paste had not been installed at the flange, it was necessary to remove the riser and reseat it in the flange.  It took about two seconds to remove the top two nuts, and simply another whole week to get the bottom one out!  With the help of a fellow dock mate, Jim, to gain leverage to back off that nut, and a full day of hard work with shipmate Dave Galson, we got it removed, patch-pasted and replaced.  Maybe it’s just my imagination, but the engine’s running much better now.  I would recommend this job to everyone – learn to trust your PB Blaster and a good wrench and long screwdriver.

[Stu Jackson]

I also recall that when we cleaned everything up we had to be VERY careful installing the green gasket.  One of the holes in the gasket, probably the bottom one, is VERY close to the edge of the material.  We cracked it when putting it on, and had to go buy a new gasket.  How'd we find out?  After putting everything together the first time, it leaked!  So, either buy two gaskets, or be VERY careful when putting the first one on!

[horsemel]

Stu, I did not know about the gasket.  I have the parts book for the engine (on the boat of course and not here), is the part number in it?  If not does anybody have a part number?
Mark Mueller

[Stu Jackson]

Mark, you can find the parts numbers on the Manuals page from the wiki.

http://www.c34.org/manuals/index.htm

That C34 Tech wiki has a lot of material that's really useful, and almost saves having the printed manuals obsolete.  Many of us have downloaded them to our own hard drives for quick reference.

[Ron Hill]

Mark : I have mentioned Stu's suggestion a number of times.  That gasket is special and cost a whopping $3.00 !! - just go ahead and buy two!! 

Maintenance Tip the innerads of a socket come in two dimensions, a 12 point (cheap) and a 6 point (more expensive).  You are less apt to round off a frozen nut/bolt with a 6 point !!

See if you can get a socket on that nut and use an impact wrench to break it loose.  Maybe they even make a vice grip socket ??

Sorry, I don't have any better advice.   

[prh77]

Catalina Direct sells the gasket.

[sailaway]

Mark
 I  was told diesel engines do not produce CO2 only gas engines Charlie.

[horsemel]

Thanks for the help.  I will get the gasket ordered and slap some muffler paste on it in the short run.  When they mentioned wrapping the riser after adding the paste, what do you wrap it with?  I think we have some extra Christmas wrap in the basement. :) Not too sure what a impact wrench is, don't know if I ever saw one.  All I have been able to get on the nut is a open ended wrench, so I will cut away the insulation that is preventing using a socket.  I will keep you posted on the outcome.
Mark Mueller

[Stu Jackson]

1.  When they mentioned wrapping the riser after adding the paste, what do you wrap it with?  I think we have some extra Christmas wrap in the basement. :)

2.  Not too sure what a impact wrench is, don't know if I ever saw one.  

Mark,

1.  Re read Terry's post, he told what to use.

2.  Google an online tool supply store and do a search on impact wrench and impact screwdriver.  They'll give you pictures and explain it all.

In the long run, the very fact that many of us have (eventually) gotten them off means that you, too, can do it.

It takes time and patience.  You're halfway there - stay with it - you can, and will, do it.