T-handle blue drain lines

Dtrimm1

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Mar 29, 2020
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2
I noticed that the T-handle drain lines on my 3.0 mercruiser has water leaking out the capped end and running down the line. It's just dripping now but worried that it might get worse. Should I just replace the lines with plugs?
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Jul 23, 2011
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51,365
those plastic blue wonders should be replaced every few years. they fail after a while because the plastic gets brittle

Hardin marine makes stainless steel versions for not much more than the plastic ones.

the thread is 1/2-13 with an o-ring.

you can use a 1/2-13 bolt, 5/8" long with a flat washer and an o-ring in a pinch.
 

alldodge

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Mar 8, 2009
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You can get stainless steel replacements from hardin marine
 

andrewterri

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Jun 25, 2014
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437
Thanks for the info on Hardin Marine. I am at their site now looking for them. Are you talking about the stainless pipe plug? Trying to find if they have something like a handle on it similar to the plastic ones. Chemistry was to long ago so you will have to help me out, putting stainless on cast iron, will that cause a reaction? I think the thermo housing in a 4.3 mpi is cast iron right?
 

alldodge

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The fittings will not screw into cast iron (NPT thread) but will screw into brass. Brass in cast and brass in SS. There remains an issue with dissimilar metals. Fresh water not much of an issue, but salt a bit more. I'm in fresh and have been installed for years and no issues
 

andrewterri

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Jun 25, 2014
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437
Now you got me wondering if they will work for me. Do you know if the thero housing is cast on a '14 4.3? they advertise them replacing the blue plastic ones but does not say anything about it not working for any applications so makes me think I can use them. Am i on the right track?
 
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