Help with identifiing a part on a 350mpi horizon

[stormyj]

Hi all, Need some help identifying a part on my mercruiser 350 mpi horizon motor, with Air Actuated Single Point Drain System. System wasnt pumping up and releasing water, so fell back to the 3 point system, where plugs were breaking off, hurray, got those all out, put in new plugs, but now, water is still dripping, very well, out of the bottom drain on the port side of the motor. Not the plug, but out of the little orange tube that comes out below the blue plug. Im thinking, that when I was messing with it and the actuator, it got some rust in it, and will not let the little hole close again. I want to take the part off, and see if I can fix it, but not sure what it is, or how to remove it. I have attached the pic. It is the part that the blue plug screws into and the orange pipe comes out of. Its hard to see down there, maybe i might just have to pull the orange rubber pipe out and push a screwdriver up in there and to get thing to flush out what ever is blocking it. Any ideas???

 

[stormyj]

It turns out that it is a water distribution housing. anyone know anything about this thing, is it easy to get out, anything I should know? Thanks
https://www.mercruiserparts.com/Merc/MidasImagesNew/COMMON/36069.gif

 

[Grub54891]

Remove the entire drain system, throw it in the trash and drain the block as you normally would. If rust flakes are plugging up that system, you can't be sure the block is draining. It will damage the motor.

 

[achris]

... Single Point Drain System....

Single point block cracking system! Another of Merc's 'finest' ideas.

If you have access, remove the entire thing, toss it. Drain as you would any other engine, by the block drains directly (and the exhaust manifolds), and poke the holes with a small screwdriver or bit of stiff wire.

Chris.....

 

[achris]

...maybe i might just have to pull the orange rubber pipe out and push a screwdriver up in there and to get thing to flush out what ever is blocking it. Any ideas???

There is (from memory) a toilet drain-type rubber 'seal' on the end of the vertical rod. It just needs to get the tiniest piece of grit under it and it'll drip until the end of days... Useless idea

Chris...

 

[stormyj]

There is (from memory) a toilet drain-type rubber 'seal' on the end of the vertical rod. It just needs to get the tiniest piece of grit under it and it'll drip until the end of days... Useless idea

Chris...

This one doesnt have the vertical rod. It is the air actuated system. That didnt work, so pulled all the plugs. which is what Im going to end up doing in the future I think.

 

[QBhoy]

What’s this air actuated system ? Haven’t heard of that ? Not sure this is technically the single point system to be honest. Looks the same as the system on a friends 350 mpi. There is a drain point on that unit pictures that does act communal to a few drain sources. But there are still a couple more drain points to take out elsewhere too. The single point drain system (as far as I know) means it’s literally one blue drain valve you turn open that releases all drains.
Either way…if you are keeping this system active, also check each individual source that feeds into the communal system too. Just to make sure.

 

[stormyj]

The air actuated and the single point drain systems are almost identical. The single point has the blue handle on the top of the engine that goes down to the water distribution housing under the engine, the round part above. the air actuated system is almost identical, except instead of the blue handle, it has a blue pump on top you connect and pump a small manifold on the top of the engine which opens the valves in the water distribution housing. It uses 4 small plastic tubes from the top to the bottom. All kinds of things can go wrong with these, as Im finding out. they rub, split, break, and then dont produce enough air pressure to open the valves in the distribution housing.
This is the air actuated system. The tubes connect to item b and go to the water distribution housing

Heres the blue dial version.




From what i understand from others, they both suck. lol

 

[QBhoy]

The air actuated and the single point drain systems are almost identical. The single point has the blue handle on the top of the engine that goes down to the water distribution housing under the engine, the round part above. the air actuated system is almost identical, except instead of the blue handle, it has a blue pump on top you connect and pump a small manifold on the top of the engine which opens the valves in the water distribution housing. It uses 4 small plastic tubes from the top to the bottom. All kinds of things can go wrong with these, as Im finding out. they rub, split, break, and then dont produce enough air pressure to open the valves in the distribution housing.
This is the air actuated system. The tubes connect to item b and go to the water distribution housing
View attachment 353869
Heres the blue dial version.

View attachment 353870


From what i understand from others, they both suck. lol

Ah. Very clever. Never noticed a system like that in person. Fair play.

 

[achris]

Ah. Very clever. ....

And just as good at cracking blocks.

 

[QBhoy]

And just as good at cracking blocks.

I’ve certainly been aware of that happening chris. No doubt.

 

[stormyj]

Yea, i have plans on draining by blue plugs and flushing the raw water side with AF to prevent anything bad from happening. Man, I cant wait till I move to Florida. Bahamas, here I come.

 

[QBhoy]

Yea, i have plans on draining by blue plugs and flushing the raw water side with AF to prevent anything bad from happening. Man, I cant wait till I move to Florida. Bahamas, here I come.

Florida sounds good to me too. I was out this evening on my wee outboard cuddy boat. Up here on Loch Lomond Scotland. Snow on the hills already !
About the flushing…I’d suggest you fill rather than flush. Up to you though.