Broken blue drain plug

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05StingRay

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As the cool weather sets in I decided to drain the water from the engine. Opened up the blue handle and went to open the drain plug on the thermostat housing. The ears on the blue drain plug broke off in my hand, apparently they get a little brittle over time? I tried to get a bite on the plug with pliers but had no luck. Anyone have any suggestions on how to get this out now? TIA

Nate
 

Scott Danforth

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remove them and the adapter, go with brass plugs
 

nickmo

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That happened to me a while back. I drilled a small hole in it, stuck a nail in the hole and was able to get it out with a visegrip.
 

dingdongs

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Drill a small hole then bang a torx bit into it. Worth replacing the set every few years in future.
 

05StingRay

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Ok so I used an ez out to get the drain plug out but it left some of the blue plastic in the threads of the housing. Two questions, 1. how do I go about removing the adapter that the blue plug screws in to if I were to replace it with a brass plug? What size plug will I need? 2. Any recommendations for getting the plastic out of the threads if I continue to use the plastic plug?
 

airshot

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Off the top of my head I believe mine is an 1/8" pipe thread?? After removing the plastic crap buy yourself a pipe tap for the size you have, most good hardware stores will have them for a few bucks. Nice to have to clean out the threads every so often so the new brass plug will seal better. Some guys drill a hole perpendicular to the square on the plug and insert a piece of metal rod or a nail to act as a handle but still use pliers or other tool to be sure new plug is tight.
 

Pete104

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Can't imagine how threads were left behind unless it was cross threaded to start with. May be why it was broken.

The thread of the blue plug is 1/2-13. You could make a thread chaser for from a 1/2-13 bolt. Just grind an angled slot in the threads of the bolt so what ever is coming out of existing threads has a place to go. Run in & out a couple times.
 

05StingRay

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Thanks everyone for the help, I bought a 1/2-13 bolt and a 1/2-13 tap to experiment with removing the plug remnants that were in the threads. Bolt wouldn't start at all so had to go for the big gun with the tap. Just twisted the tap by hand so that I wasn't creating new threads and the plug fit great. Still going to replace the blue plug with brass but for now it will at least hold water. Thanks for all your help!
 

Pete104

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Your going to have a hard time locating a brass replacement for that plug. Use another plastic plug with a little grease on it. Just tighten with your thumb & index finger. No pliers or wrenches required!
 

alldodge

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I use the plastic plugs but they also get replaced every other year when the impeller is replaced. Main reason is they are real easy to remove and when I have to hang upside down to get at a couple of them it helps a lot with this old guy. Can get a 5-pack for 10 to 15, just need to do some looking. Just noticed Hardin Marine has some made out of stainless for under 6 each. The O-rings come in a 10 pack
 

H20Rat

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They break from being cranked in too hard. It takes surprisingly little torque on those! I snapped both of them on my boat the first time I took them out, every year since they have easily came out with very little resistance.
 

dslaney

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Broken water drain plug for Mercruiser 4.3L I recently broke one of the blue plastic drain plugs as I was unscrewing it. Thanks to many post I had some ideas. I successfully removed the plug using a Ryobi spiral screw extractor set. It has reverse thread so it tightens in the counter clockwise movement. These plugs are typically hollow so you can select a screw extractor from the kit that is appropriate. Worked well. Thought that I would share this as an option. Easier than a screw driver.
 
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