Leftover brass plug during reassembly 5.7

zslave

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Oct 17, 2013
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Over the past few months I have torn my 1996 Bayliner 5.7 mercruiser engine down and put it back together. Tomorrow it is going back in the boat but tonight as I was finishing up odds and ends I found a small brass plug that I cant figure out where it goes. It has sand in the end of it so that tells me it was part of the cooling system (raw water) but I can't find a spot for it. I know it isn't for the manifold drains or the 2 block drains. Help?? I hate to put it in and it spits water all over and have to ask for help to pull it and do this again.. Thanks
 

dubs283

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Re: Leftover brass plug during reassembly 5.7

might be for an oil cooler, can you post a picture of it??
 

zslave

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Oct 17, 2013
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Re: Leftover brass plug during reassembly 5.7

cant figure out how to post pic. it is smaller brass plug with a hole in the thread end that was full of sand. kinda like the plug is hollow. It seems to be fine thread and had a redish thread sealer on it.
 

dubs283

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Re: Leftover brass plug during reassembly 5.7

sounds like a standard brass mercruiser block drain valve, the hole is designed to allow draining without removing the plug from the housing - but i recommend removing the plug entirely to drain especially during winterizing

did you have two piece block drains with two brass pieces?? or brass housing with blue plastic plug??
 

zslave

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Oct 17, 2013
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Re: Leftover brass plug during reassembly 5.7

I had the two piece brass drains with the T end to twist for draining. The exhaust has plastic T drains. this is smaller and fine thread.
 

zslave

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Re: Leftover brass plug during reassembly 5.7

For some reason it isn't working.
 

dubs283

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Re: Leftover brass plug during reassembly 5.7

one way to avoid leaking water into the bilge is to run the motor on the ground prior to install, check for leaks

this is one thing i always do prior to motor install (to check for leaks/other issues)
 

zslave

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Oct 17, 2013
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Re: Leftover brass plug during reassembly 5.7

Frustrated..cant post the pic.
 
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