Alpha 1 Gen 2 - leak & transom service questions

nola mike said:

That can also still be a rotten transom. Bolts holding y pipe can corrode on the bottom.

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true. If I remove the manifold, should I see signs of a leak through there? if so, then I can start with the manifold, and if not, then pull the motor to check for rotten transom? Or would you recommend that step, anyway?

When you drop the manifold it should be pretty easy to see if it is the gasket. Mine was cracked, but if it’s squished out or such you should be able to spot it.

Grub54891 said:

When you drop the manifold it should be pretty easy to see if it is the gasket. Mine was cracked, but if it’s squished out or such you should be able to spot it.

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I’m not seeing any obvious sign of gasket leak. I also don't see a mercathode wire on the inside near the trim hoses, or a mercathode junction box anywhere in my electrical path. Do mercathode components always require electricity?

The seal on the front timing cover you can replace by just removing the harmonic balancer and then pop out the old seal and install a new one. Just go to your local auto parts store and ask for one for a 1999 S-10 with the 4.3, you can pick any vehicle with a 4.3 to have them look it up. I’d try that first for that issue. You will need a remover and installer tool, you can rent them from the auto parts store.

As for the trim pump hoses . . . make sure it is not the y-pipe gasket leaking instead of the trim pump hoses.

ShoalSurvivor said:

I’m not seeing any obvious sign of gasket leak. I also don't see a mercathode wire on the inside near the trim hoses, or a mercathode junction box anywhere in my electrical path. Do mercathode components always require electricity?

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Pretty much how mine looked. Once I pulled it down it was obvious. it certainly wouldn’t hurt to replace the gasket just for peace of mind. As others have mentioned, the Y pipe could be it also, or your transom is compromised. As far as the mercathode, I don’t know, mine didn’t have one.

ShoalSurvivor said:

If this is the source, should I expect to have water spill out of the manifold when I remove it? just setting expectations. thanks.

I have new bellows, trim sensors, etc. and was planning on replacing all of that anyway. I suppose it would be easier to do the manifold work, when I service the bellows. However, if the leak is through the manifold, I would like to test it BEFORE doing the bellows work and/or pulling the motor for the oil leak. One step at a time . Does this make sense, or should I just pull the motor, do the oil leak repair, replace the bellows and sensors, manifold and hoses, then put it all back and just hope for the best?

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a little water may come out when you remove the manifold but unless the bilge is full wont be much

Its realtively easy to do the manifold gasket I would do that first and test before you tear everything else apart.

ShoalSurvivor said:

I’m not seeing any obvious sign of gasket leak. I also don't see a mercathode wire on the inside near the trim hoses, or a mercathode junction box anywhere in my electrical path. Do mercathode components always require electricity?

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not all engines will have a mercathode on it from factory. Looks like yours did not have it. the mercathode bolts on in place of the annode on bottom of gimball housing

i have all the cathode pieces installed on the out drive, trim cylinders, etc. I just dont see the electrical manifold or wires. Curious if there is a non-electrical installation and an electrical one.

i will replace manifold gasket. I don't think I could do much more to evaluate the ypipe gasket or check for transom corrosion with the motor in.

ShoalSurvivor said:

i have all the cathode pieces installed on the out drive, trim cylinders, etc. I just dont see the electrical manifold or wires. Curious if there is a non-electrical installation and an electrical one.

i will replace manifold gasket. I don't think I could do much more to evaluate the ypipe gasket or check for transom corrosion with the motor in.

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they are not cathodes - those are anodes they are just sacrificial metal made of zinc, magnesium, or aluminum (depending on the water you boat in).

the mercathode is this system- uses 12 VDC to create a cathodic protection around the outdrive. The piece in the upper RH corner of pic replaces the anode on the underside of gimbal housing wires go up through just like your hydraulic lines ( wires go through manifold )


best bet is to get a scope camera or scope attachment for your phone so you can look in there and see when you dunk it after replacing .

thanks for the explanation. That makes sense. They are sacrificial.

I can reach under the YPipe and stick a thumb in the hole of the transom inside of the transom assembly, where the hydraulic lines go in, and I can feel the water when it accumulates in there. I tried to use a borescope to see if I could pinpoint the source of leak inside of that cavity, but was unable to get a clear focused view, but I had found the location of the leak. If it's the manifold gasket, it would be easy to tell if replacing it that solved the problem.

it's entirely possible that it's the YPipe gasket, since that is above and inside of that cavity. I think I'm gonna access the top of the YPipe and fill it water from the hose, and block the outflow holes to see if water appears. I can do that while I wait for the gasket to arrive.

Bt Doctur said:

remove the drive and plug the relief holes .drain and remove the risers, fill Y pipe with water to see if it leaks inside the boat

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I plugged the Y pipe relief holes, removed a riser, then filled the Y-pipe with water from a hose. Water held at about 3" below the flapper, well above the leak location, for 10-15 minutes (with hose running and with water draining from the raised drive).

No water accumulated inside the boat. No water accumulated in the hydraulic line pass thru area of transom (which was filling with water when submerged).

I also removed the hydraulic manifold cover and found no water.

Does this indicate that the Ypipe and gasket are probably ok, but indicate a rotted transom or leaking transom bracket?

is my next step to remove the motor, inspect, and submerge it to find the leak? if so, does the YPipe need to be sealed before submerging?

thank you!

You removed the hydraulic manifold cover. Did you drop the manifold itself?

Grub54891 said:

You removed the hydraulic manifold cover. Did you drop the manifold itself?

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Fair question. no. it appeared very well sealed. the gasket was in tact, no signs of cracks or deterioration, no signs of moisture, and the hydraulic fluid is free of water. In short, i didn’t see any way that the manifold cover could be allowing the flow that i witnessed on the interior. I opted to proceed to the Y pipe gasket before prying the manifold apart.

ShoalSurvivor said:

Fair question. no. it appeared very well sealed. the gasket was in tact, no signs of cracks or deterioration, no signs of moisture, and the hydraulic fluid is free of water. In short, i didn’t see any way that the manifold cover could be allowing the flow that i witnessed on the interior. I opted to proceed to the Y pipe gasket before prying the manifold apart.

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Mine looked good also. I pulled it down anyway, sure enough it had a crack in the gasket. It won’t let water into the hydraulic oil, that’s a basically sealed system.

Grub54891 said:

Mine looked good also. I pulled it down anyway, sure enough it had a crack in the gasket. It won’t let water into the hydraulic oil, that’s a basically sealed system.

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I pulled it down. the gasket is unmarred - clean solid surface around the entire perimeter. I ordered and will replace, however this does not appear to be the breach.

however, the hydraulic fittings inside were covered with salt. clearly, salt water was accumulating inside of that cavity, the same cavity where the lines enter from the inside, where the leak originates in the bottom of the inside transom bracket.

With the Y-Pipe test not indicating the y-pipe gasket, I am strongly suspecting that the transom seal is broken in that area, possibly due to transom rot, or possibly due to an idiotic strike of the drive in the driveway. Last spring, I was backing out of the driveway, and the drive was not all the way up. there didn't appear to be any damage to the drive, but certainly, the transom seal could have been compromised. There is no obvious looseness or gap on the bell housing or transom brackets, but without any obvious other indicators, this seems to be a likely culprit, given that the leak started at some point after that.

I think I'm looking at resealing the transom (best case), or repairing rot that caused it, or may have occurred after it started leaking (worst case).

Time to pull the engine? Any suggestions wrt resealing a transom?

Start by drilling some 1/4” holes from the inside of the transom, starting at the bottom As close as you can to the housing. If shavings come out black and squishy, it’s got rot. Work your way up, out and such till you come out with clean shavings. That will give you an idea how much rot there is. Do not drill all the way through to the outer shin. If it has rot, drive, motor and anything attached to the transom has got to com out for a proper transom replacement. Let us know what you find.

Grub54891 said:

Start by drilling some 1/4” holes from the inside of the transom, ...

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I cannot reach a drill to that location. If it is rot, the engine has to come out anyway, right? And with the engine out, I can pinpoint where to drill.

Wouldn't I want to inspect the mount with clear visibility before compromising the transom?