Dufour Owners Association: new forum comment on Replacing wet exhaust hose, exhaust elbow to silencer (45e Performance)

New comment from Andrew Spruell

Hi Andrew

Whilst I follow Jeremy’s line of thinking I do agree that what you say about SS elbows make a lot of sense.
More importantly to my mind is that whatever elbow you fit it will coke up given time. I find 5-6 years is about the limit before it comes a significant problem. This is despite never running the engine in neutral even when just battery charging and always using a reputable fuel additive. Although in theory it is possible to decoke these elbows in practice I have found it to be rock hard and very difficult. Soaking the elbow in acid may do the trick but that would almost certainly finish off a cast iron one. So I regard it as a routine service item to replace every 5 years. Interestingly, I am sure I read somewhere that Yanmar on some of their engines recommended replacing the elbow every 2nd year but I may be totally wrong on that.
The bottom line is that these elbows need regular inspection

Andrew

https://www.dufour.org.uk/members-forum/replacing-wet-exhaust-hose-exhaust-elbow-to-silen

Original Post by Andrew Sansome

Replacing wet exhaust hose, exhaust elbow to silencer (45e Performance)

<p>I have a 2010 45e performance with a V.P. D2-55F. This has suffered the well known exhaust elbow corrosion problem (cast iron!) and I will therefore replace it with a cast stainless replacement. I am expecting to find that the corrosion has extended around the exhaust elbow spigot, between the cast iron and rubber exhaust hose and therefore that, as a consequence, separating the two will prove difficult. I therefore plan to replace the section of 57 mm wet exhaust hose between the exhaust elbow and silencer.</p>
<p>I am hoping that someone will have attempted this job and can provide some pointers.</p>
<p>I have a couple of questions;</p>
<ol>
<li>Am I correct in anticipating that it will prove difficult to separate the exhaust elbow and hose?</li>
<li>Should I expect the hose to be irredeemably damaged by its removal (it is 12 years old so should probably be replaced)?</li>
<li>What length of hose will I need to purchase to replace this section?</li>
</ol>
<p>The boat is lying in Corfu where it is proving difficult to source the hose. I therefore need to purchase a length in the UK, but how much should I take?</p>
<p>Thanks</p>
<p>Andrew</p>

comment made on…

<p>Quick update.</p>
<p>Removed the old cast iron elbow – what a mess! Extensive corrosion with three pin holes. BUT the real problem was that one of the two channels through which the water flows into the exhaust was completely occluded whilst the second was badly restricted. Water had been forced through the internal corrosion and had been spraying back into the exhaust manifold. The result is extensive corrosion of the manifold which will need to be removed at the end of the season to be repaired.</p>
<p>The exhaust hose could not, as anticipated, be removed from the exhaust elbow without destruction, but separated from the silencer easily. The new section is exactly 500mm long.</p>
<p>It is striking how much more water is now pumped through the exhaust!</p>
<p>Volvo should be ashamed of themselves. I understand that they have a financial incentive to see regular failure of this component and consequential damage, BUT failure risks entry of water, leakage of hot exhaust gases into the boat and engine failure whilst the vessel is under way. If this were an automotive problem then I suggest a general recall notice would have been issued and the exhaust elbow would be replaced with a cast stainless steel part. What engineer would design a critical component in cast iron knowing that hot salt water would be passed through it?</p>