Alternator bracket upgrade and now exhaust system coolant leak

MitchK

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Sep 22, 2017
102
Capital Yachts Newport 28 Burbank, WA
Hi all. Due to various circumstances, I have finally been able to get back to the boat work and the starting issue I had earlier this year.
The non-start issue was traced to a faulty fuse holder in the start lead that goes to the starter solenoid. Once that was identified and temporarily bypassed, the engine started easily as always.
Now the fun begins. To get to the wire connection at the starter solenoid, the alternator needed to be removed. Since the starter had been acting flakey, I decided to replace it. Since I was replacing the alternator any, I figured it was time to do the alternator bracket upgrade. We have an early Universal M-18 Diesel with the original alternator bracket mounted to the front timing gear cover. Which of course is subject to breaking the ear off the cover. So A upgraded bracket was ordered.
As I was preparing to install the bracket, I discovered the exhaust manifold studs were too short, so the exhaust manifold had to be removed so the studs could be replaced. So the riser elbow had to be removed too. I was able to remove the elbow from the hose that goes to the water lift muffler without much issue, and get everything out without too much trouble.
Getting it all put back together went mostly without incident. Re-filled the coolant and got all of the wires re-connected, opened the seacock and she started right up and runs as good as ever. So I am feeling pretty good at this point. So I run her for a while to get the air out of the cooling system. Checked the forward and reverse gears. Everything as it should be. Still feeling pretty good. Figured I would give it one last visual inspection before I called it a day. Crawled back down the quarter birth with a flashlight and took a good look. That's when I saw the "new" problem.
It appears the water lift muffler is not mounted solidly to the hull, and during the removal of the exhaust hose, the muffler moved a bit and appears to have cracked the fiberglass elbow that is between the muffler and the through hull.
The current plan is to replace that fiberglass elbow with one made of stainless tubing. I found stainless tubing ones made out of 304 stainless that should work.
Has anyone in the group had to replace this elbow? If so, how did you go about access it? Our N-28 still has two of the original plastic gate valves connected to the cockpit drain through hulls that need to be replaced too. So I may try and do them at the same time I do the elbow replacement. From the looks of it, it is going to be a very difficult job due to access. Hopefully I am wrong. Here is a couple of pictures with the leak area circled in red.
 

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MitchK

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Sep 22, 2017
102
Capital Yachts Newport 28 Burbank, WA
After cleaning out the starboard lazerette so that I could access the leaking elbow, it actually came out fairly easily. Yes, access was limited, but the clamps were installed so that they were easy to loosen.

It appears the elbow was installed to provide clearance for the Edson Helm assembly. As you can see from the pictures, someone had worked on this elbow before. There was a fair amount of some sort of sealant (black rubbery material) on each connection to the elbow. It's not silicon, and it is still flexible.

After I got it removed, I discovered the cause of the leak. The elbow had worked its way out about 1/8". This allowed water to leak at that connection.

The elbow is cracked, but I did not crack it. It appears it had cracked sometime in the past and a previous owner had used the sealant as a repair.

The leaking end of the elbow is also tapered and deformed. At first I thought it was from heat, but after a closer look, it was just a poorly made part that cracked when the hose clamp was tightened. A new elbow and piece of wet exhaust hose has been ordered, and should be here late next week. The pictures do a better job of explaining what I found.
 

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MitchK

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Sep 22, 2017
102
Capital Yachts Newport 28 Burbank, WA
The new elbow and replacement hose arrived this past Wed. Took the parts out to the boat this past Fri to install. Cleared everything out of the aft locker again, climbed into locker with parts and tools, and installed the new elbow/hose. Everything went as planned. Crawled back out of the locker, turned on the battery, and started the engine. Engine started right up, and I checked for leaks. No leaks.
Stuffed everything back into the locker, and decided to go sailing. Needless to say, once I got out of the marina. the wind completely died. Just my luck. Motored around for a while, then returned to the marina. There is always next weekend.
Here are a couple of pictures of the new elbow. It is a bit shorter overall than the original, but there was plenty of hose to make the connections.
 

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MitchK

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Sep 22, 2017
102
Capital Yachts Newport 28 Burbank, WA
Stu, no, I am staying with the existing hose. Its about 12-18 inches long and plenty flexible. I looked at the hump hoses, and did not see a significant benefit to going to one.

That is an interesting link you posted. Probably should spend some time going through all of it.

I did ensure the new bracket was aligned properly. One thing of note. The new alternator bracket when installed on an M18 is not adjustable. There is one set of slots for the front studs, but the second set of hole in the bracket are not slotted. Without removing and modifying the bracket, it is fixed in position. With that said, I had to add three flat washers between the cover and bracket on the front of the engine. I also had to back out the one stud in the front cover a turn or two so the nut could be installed. I verified pulley/belt alignment and everything was good.

I also did not have to use the rubber elbow or the copper elbow that come with the kit for the upgrade. As you can see from the pictures, they were not needed.
 

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