single point water draining system

Last Dollar

Cadet
Joined
Jun 30, 2009
Messages
21
I have a Mercruiser 5.0 with the single point drain system for draining the engine. Last season I constantly noticed water in the bilge after each outing. Since I trailer this boat I suspected a leak somewhere in the cooling system. It was not bad so I did not address it immediately. Now while preparing for Summer, I noticed antifreeze in the bilge. Since I always pour antifreeze into the block from the thermostat I was certain of a leak in the plumbing. Further examination after adding more antifreeze revealed a fast drip from the water distribution housing 3 inch orange hose. I read on other forums about the issue with the water distribution housing cracking. I pulled it off and see no visable signs of a crack. However it was much easier to see how the long handle and rod shuts off the water flow and looks like to me this grommet is just worn out or not sealing properly which allows a seepage. Since there is a blue plastic plug right next to the orange hose, what is the purpose of the elaborate rod coming all the way down from the top of the engine?? Is this just marketing hype to use during the sales pitch? A salesman could say "you don't even have to bend over to drain the system, just open the blue handle on top of the engine."
Now this water distribution housing and internal seal is sold together. You cannot buy just the seal. The housing is $200.

Has anyone come up with a fix for this?? I would like to seal the orange tube and just drain the system using the blue threaded wing nut right beside it. I can still bend over. Actually I would rather bend over to winterize rather than bend over at the Mercruiser parts counter while forking out $200 for a plastic part that very well may break or have the seal wear out. Anyone's thoughts or experiences would be appreciated.​
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
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Jul 23, 2011
Messages
49,585
remove the single point drain and go to simple brass plugs about $8 worth from your local hardware store. the single point system fails and the block cracks, even if you pour antifreeze in it since the water was never drained

the single point drain system was developed to make points with consumer reports (less maintenance points = higher consumer reports rating points). it was not designed for longevity.

plenty of threads on it.
 

alldodge

Moderator
Staff member
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Mar 8, 2009
Messages
42,067
Agree, remove the system and have a safer winterization. If you want to keep it, the distribution housing has been replaced with brass fittings by Bt Doctur in one of his designs. Doing this the housing will last but the one turn handle won't be there.
 

Bt Doctur

Supreme Mariner
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Aug 29, 2004
Messages
19,292
original was brass but have done the same with copper fittings, let me grab the pic
 

Bt Doctur

Supreme Mariner
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Aug 29, 2004
Messages
19,292
3/4 to 1 inch elbow or street elbow, 3/4 T , a bit of 3/4 copper pipe, and a copper drain button that I can supply to you
 

Last Dollar

Cadet
Joined
Jun 30, 2009
Messages
21
Had to look at this for a while to realize it must be two of the devices laid out side by side??? correct?? you make these up and sell them?? need more info, Are the diameters for the hoses correct??
 

Bt Doctur

Supreme Mariner
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Aug 29, 2004
Messages
19,292
the diameters . are correct for the hose ,the reason there are 2 is because the customers boat is a twin.
I can make one for you and ship it if your USA. The junction block with all the hoses can be replaced by a section of copper 1 inch dia tubing or just remove the hoses and cap the ends with rubber caps.
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,292
These are now available, PM if interested if you want a water dist housing with drain that will never crack

 
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