Installing new exhaust elbows``

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Bigfish

Senior Member
Joined
Jan 25, 2013
Messages
297
Location
USA
Vessel Name
My Lady
Vessel Make
Formosa 42 Double Cabin
Hi folks,

Just put one of my two new exhaust elbows on my 120's. New hoses, heavy duty clamps, and new gasket that came with the elbows. However! The 3 1/2" hose slid effortlessly over the flange as I coated both the hose and the elbow with a film of Dawn dishsoap to help. Seemed very loose, but he hose was the same hose I took off. Cranked and cranked the clamps quite a ways but it still leaks a little water at the bottom of the hose at the elbow. But worse, it's leaking at the bottom of the elbow at the manifold. I cleaned the manifold of all old built up chunks of whatever and I painted the new elbows and it was very flat. The gaskets that came from Bomarc were very thick and I would have thought they'd seal easily. What now? I'm about to do the other engine but I was wondering if I can use some sort of gasket sealer at least on the gasket but what about on the hose over the flange?? Anybody else have this issue?

Thanks in advance..
 
I had a large new stainless mixing elbow also made and I fitted it recently also. The old exhaust rubber pipe also slid way too easy over the new elbow. But the big stainless clamps have held it really tight with zero leaks.

As for the fitting to the exhaust off the downpipe flange from turbo, that had to be chipped away of old metal, I made it really flat, cut a gasket from high temp material which had the metal in it and fitted it. I also used high temp gasket exhaust sealant. With the new bolts and nuts and washers she tightened up well and no leaks at all.

so yes I used sealant rated for 1100 f temp.
 
Your difficulty tightening and sealing the hoseclamp and hose, reminds me there are 3" and 3.5" elbows for the L120.
 
For the leak at the manifold, I always thinly coat my gaskets with Permatex Black gasket sealant. Just a dab between your gloved thumb and index finger and pinch the gasket as you smooth it on completely. This coats both sides for a smooth film that makes gaskets seat and seal. I almost never have problems doing it this way.
 
Regarding hose to exhaust elbows, I'm a big fan of "T" bolt clamps. 2 clamps 180 degrees apart has always worked for me. Definitely a stronger clamp that yields a higher compression force on the hose.


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Ted
 
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