Alpha 1 Gen 2 - leak & transom service questions

[ShoalSurvivor]

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

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?

 

[Grub54891]

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.

 

[ShoalSurvivor]

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.

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?

 

[Jmunk]

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.

 

[tpenfield]

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

 

[Grub54891]

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?

View attachment 413605

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.

 

[Scott06]

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?

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.

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?

View attachment 413605

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

 

[ShoalSurvivor]

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.

 

[Scott06]

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.

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 )

Mercury Marine/MerCruiser New OEM Mercathode Kit, Alpha/Bravo/R/MR, 8M0085693

Mercury Mecruiser New OEM Electrolysis Mercathode Anti Corrosion Kit 8M0085693

leadersrpmshop.com

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 .

 

[ShoalSurvivor]

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.