V8-270-C-B Exhaust bellows (hose) replacement

[Jeff J]

I have a leaking exhaust bellows between the left elbow and the Y-pipe. A local shop recommended changing it but didn't offer any tips on how. I slid the bellows down the Y-pipe thinking there may be a gap to work it off the pipe and install a new one but there only appears to be a 1/2 inch or less to work through. Looking at the parts diagram and the boat, my best guess is that I need to remove the cast iron elbow behind the catalytic converter to replace the bellows. I have searched the manuals, google, this forum and youtube without finding anything useful on bellows inside the hull on a motor with a catalytic converter or even what it takes to replace the catalytic converter. I have the EFI, EGC, GXi, transom shield, SX-A and operator's manuals and they don't have any information. I don't want to split that big cast iron housing open without guidance or even an idea what to expect. Can anyone point me in the right direction?

 

[Scott Danforth]

get as set of elbow gaskets and pull the elbows

 

[Jeff J]

What about torque values on the bolts and nuts? It’s pretty standard for me to use an X pattern when tightening things but it would also be good to know if there is a specific sequence to follow. I don’t want to replace a bellows just to start a leak at the catalytic converter by doing shade tree maintenance.

 

[Scott Danforth]

covered in the factory manual. Since you have CAT's in the exhaust, I would definitely look at the manual. (I dont have a copy)

additionally, those hoses should last 30+ years. only failure to maintain cooling water system would kill them (lack of water and exhaust temp goes from 200F to 1200F)

 

[Jeff J]

I pulled the elbow. The bellows is soot covered as can be seen in the photo. It is also soft and pliable. Looks worse out of the boat. Cannot find a hole but no evidence of it leaking around the ends either.

I have a pretty good collection of manuals from Volvo. None of them talk about the catalytic converters, elbows or bellows. One talks about the exhaust manifolds but goes no further downstream and another talks about the bellows in the sterndrive. I couldn’t find anything that covers part in between the two. The boat is a 2015 Cobalt with 1153 hours. Catalytic converter looks very good.

 

[Jeff J]

Now that the elbow is out… maybe I should crawl back in there and check the manifold gasket in that area….

 

[muc]

You didn't post a serial number so I can only take my best guess.
Workshop Manual 47700210 is my best guess, it's a supplement to the engine manual and just covers catalytic exhaust manifolds.
There are some more parts that need to be replaced, it's not just the gasket. Be very careful with this manifold, it's aluminum with a ceramic coating. Very easy to damage the coating and ruin the manifold. ONLY use wood or plastic scrapers to clean the gasket surfaces.

 

[Jeff J]

I wish I knew the serial number. The tag on the cover is all but blank. It looks like some kind of cleaner or solvent got on it. I encountered one a while back that was missing the cover and was able to call Cobalt to get the serial number. I need to call them one of these days and do the same with this one.

I haven’t encountered a manual like you describe but Volvo Penta doesn’t advertise what their manuals cover either. Apparently, there is a cooling system manual too. I don’t know why they can’t put everything in the same book like everyone else.

 

[muc]

I wish I knew the serial number. The tag on the cover is all but blank. It looks like some kind of cleaner or solvent got on it. I encountered one a while back that was missing the cover and was able to call Cobalt to get the serial number. I need to call them one of these days and do the same with this one.

I haven’t encountered a manual like you describe but Volvo Penta doesn’t advertise what their manuals cover either. Apparently, there is a cooling system manual too. I don’t know why they can’t put everything in the same book like everyone else.

There should be a metal plate on the port side of the flywheel cover. It will be an inch or two below the bottom of the exhaust manifold.

Your engine is a 5.7 block so when Volvo started adding catalyst to them they knew they would be switching to the Gen V blocks. So rather than writing a new manual they put out a supplement. This is very common with all the engine manufacturers.

 

[Jeff J]

I understand supplements. My experience is that they get added to the existing manual instead of getting published and sold separately but these boats are the newest things I work on so my experience is probably outdated. My beef with Volvo Penta isn’t so much the multiple books as it is the way they list them to sell or download for free. If you go to the Volvo Penta website you have to input some engine information so everything that comes up should apply to that engine but there are dozens of publications listed with zero indication of what system they cover.

The manifold gasket looks okay and everything is stained from the back (bellows side) so it looks like I dodged the need to pull it.

The tips and information is much appreciated. It will greatly help the effort.

I found 2 more tags. Paper decal on the port side of the oil sump. Unfortunately, it’s not much more legible than the decal on the cover. I also found the metal plate you mentioned. It was obscured by the elbow and bellows I removed. Thanks, I don’t recall seeing either mentioned in anything I have read anywhere else.

 

[Jeff J]

I can’t seem to find any information on the internet to confirm which manual I need for the exhaust system. Even the Volvo Penta website now says no products available or only shows a fraction of the documents it did for a V8-270-C-B. I see exhaust manuals on eBay but of differing part numbers. Can you confirm the manual’s part number for me? The engine serial number is A421726 produced 2012-2013.

 

[muc]

Workshop Manual 47700210 is the correct exhaust manual supplement for your serial number.

Volvo has "updated their website. I'm thinking there are a few bugs to get worked out.

 

[Jeff J]

Thank you, I ordered the book through them so I hope that part of the system is working.