Big 6" exhaust hose - time to replace

ZZ13

Well-Known Member
Nov 25, 2009
5,319
Lady's Island, SC
Boat Info
2001 400 Sedan Bridge
Engines
Cummins 450 Diamond
The big 6" exhaust hoses have reached end of life on my boat. Time to replace them. Is there a particular manufacturer and/or construction type I should make sure to buy? They are about 1/4" thick (outside diameter is 6.5") and seem to have a metal mesh imbedded in them. I figure I'll just cut off the old ones. They are hard as concrete now after 14 years.
 
I'm just curious as to why they need to be replaced. Are you concerned they may crack, or are you already seeing signs of cracking?
 
I'm just curious as to why they need to be replaced. Are you concerned they may crack, or are you already seeing signs of cracking?
One has a quarter sized bubble where the mesh seems to have disintegrated. Another has a spider crack on the surface of it and also salt will cake on the outside of that same hose where a seam is, after a long days ride. So I figure seawater is weeping through the seam.
 
One has a quarter sized bubble where the mesh seems to have disintegrated. Another has a spider crack on the surface of it and also salt will cake on the outside of that same hose where a seam is, after a long days ride. So I figure seawater is weeping through the seam.

Gotcha. How about calling Sea Ray and asking what type they use on the newer boats? Just an idea.
 
Spec SAE J2006 Type I unless you are talking about silicone bellows....
Both Shields and Trident make top hoses.
If you are getting blisters then there may be some hot spots. Need to make sure the exhaust riser "shower" holes are all clear; sometimes they can get a bit plugged up.
 
By exhaust riser, do you mean the mixing elbow? I have Cummins and there is an elbow bolted to the turbo. Sea water comes in the top and mixes with the exhaust there
 
By exhaust riser, do you mean the mixing elbow? I have Cummins and there is an elbow bolted to the turbo. Sea water comes in the top and mixes with the exhaust there

Yes exactly. That ring of holes. Pull the hose off and they should be right there.
 
Yes exactly. That ring of holes. Pull the hose off and they should be right there.
Roger that. Pulling this hose off looks like it could be a Herculean effort. I take it I don't need to worry about the waterline? That the horizontal hose further downstream is above the waterline?
 
Roger that. Pulling this hose off looks like it could be a Herculean effort. I take it I don't need to worry about the waterline? That the horizontal hose further downstream is above the waterline?

Bill, yes the top of the hose coming off the muffler is above the water line, and actually so is the mixer, but not by much. I have had mine off before, no problems. If your blister is on the top about 4” back from the mixer, it could be because it gets too hot there when displacement speed cruising. My exhaust hoses get very hot there when running at easy displacement speed, around 950 rpm. After experimenting with the IR gun, I am now trying to keep the rpms up around 1050-1100 when slow cruising for long distances because the extra water that the sea water pump puts out at that speed is enough to fill the shower head and water comes out the top holes of the mixer, cooling the top of the hose better. I have the original hoses on the boat, but if I replace them, I might look at the blue silicone hoses, they are good for about 100 degrees more heat than the black wet exhaust hose.
 
Thanks Mark. The blister is actually on top of the second short hose just past the stainless steel elbow on the port engine. However, I have been doing a lot more slow running. I used to go on plane whenever I could. But starting this past summer we now just take our time most of the time. Usually I stick it right on 950-1000rpm. Sounds like I need to revisit that.
 
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If it’s the second hose on the port engine then it’s not from what I described, but at least that one comes off a little easier than the starboard side. Start that side by loosening all the clamps and working the hose toward the muffler, then work the stainless elbow off the other end. Good luck.
 
If it’s the second hose on the port engine then it’s not from what I described, but at least that one comes off a little easier than the starboard side. Start that side by loosening all the clamps and working the hose toward the muffler, then work the stainless elbow off the other end. Good luck.
Thanks. They both gotta go. The one between the mixer and the ss elbow and the one with the blister after the ss elbow. Right now I have the blister hose wrapped with HVAC foil tape to flatten and hold the blister. Ha! Don't tell anyone. The purists on here will grill me for that.
 
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I finally replaced these two hoses today. It was very easy. The factory hoses had no wire cool so they just cut right off. They were in terrible shape. About to self destruct. I went with the blue hoses.
756b9ffa302141374fe6dc53e9781a15.jpg
 
Looks very nicely done. Where did you end up getting the hose material from?

It was an extremely easy job. The old hoses did not have a wire wrap so I just cut them off. I bought the hoses online. Found a place selling a 3' length of the 6" Trident Blue for $235. Unfortunately the other engine needs a 11" piece and my leftover was only 8". Darn it.
 
Looks good. Do you have a bonding wire for that elbow?
I do. Its directly connected to the port transmission. I had not reconnected it yet when I took the picture. Thanks for the reminder, though. I actually had forgotten to reconnect it until I looked at the picture and realized it was still off.
 
I finally replaced these two hoses today. It was very easy. The factory hoses had no wire cool so they just cut right off. They were in terrible shape. About to self destruct. I went with the blue hoses.
756b9ffa302141374fe6dc53e9781a15.jpg
Hi Bill, nice job, I’d like to do the same.
1)- How did you cut the silicone hoses?
Or you order it already pre-cut?
2)- where did you order it, remember?

Thank you
Fernando
 

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