Blue plastic water plugs for draining cooling system

skidrow · May 2014

I have an old brittle blue plastic plug that has the "T" part broken off"... No where to grip the plug to unscrew it.... Anybody have any ideas how to unscrew it?

aero3113 · May 2014

You can use an easy out http://www.amazon.com/pcs-Easy-Out-Set-TAIE0739/dp/B0027B5GT0/ref=pd_sim_hi_3?ie=UTF8&refRID=0NPP64PNB5NV0NCW63BP Or if it's brittle enough can you break it apart?

Dream_Inn · May 2014

I've had that happen and just drilled out the plug. If you do it carefully and the right size bit, it is pretty simple.

rinker312 · May 2014

Why drain it? I've personally never removed mine. Just wondering.

Cableguy Greg · May 2014

I used an easy out to get a broken one out.

skidrow · May 2014

I'll try drilling it out...thanks.

Babyboomer · May 2014

Drive a Phillips screwdriver in and take it out I put new plugs in every 2 years

http://www.wholesalemarine.com/mercruiser-blue-plastic-drain-plug-by-sierra.html?gclid=CLO-8Ky1sb4CFWgF7AodnWYA5g

skidrow · May 2014

Tried to drill it out...pulled out most of it until it crumbled Out....now all of it is stuck in the thread with nothing to grab on to... All flush to the hole... Going to get a tap for the same size thread and try that...

rinker312 · May 2014

I'm just wondering. Why do you all take those plugs out. Do you winterize by draining the block with them?

youstolemybeer · May 2014

get an easy out the size you need (aka reverse drillbit). once the remains are out of the hole, get the brass plugs and never have to worry about that again

Babyboomer · May 2014

There is an insert in the block Merc went to plastic plugs to stop the seize of the brass plugs

skidrow · May 2014

I tried to drill it out, but it was so brittle just the threads remained in the block...tried to use a dremel, Torch, muriatic acid...nothing worked....had to remove the whole thermostat assembly as I Could not get a tap into it....finally got a tap into it to remove the plastic from the threads..while I Had it out I also changed up the thermostat....so now I will replace them every few years.... Only wasted about 5 hours.....Murphy's law..

EaglesNest · May 2014

rinker312 - The answer is yes. I do pull all 4 blue plugs to drain fresh water out before I add antifreeze when winterizing. Word of advice. don't over tighten the bottom right plug. The housing is made out of plastic and breaks easy. Just ask Dream_Inn. I replaced all 8 of my plugs last year b/c they wear over time. The gaskets disappear. Not to mention, it is possible the cheapest part on my boat.

rinker312 · May 2014

Ok thanks I figured that is what they were there for. I always winterize by warming the engine then running antifreeze through it while running. I've never had any issues even when I was in the northeast. Saves me from messing with those plugs.

aero3113 · May 2014

rinker312 said:

Ok thanks I figured that is what they were there for. I always winterize by warming the engine then running antifreeze through it while running. I've never had any issues even when I was in the northeast. Saves me from messing with those plugs.

That's how I winterize my boat

Golflover · October 2015

aero3113 said:

rinker312 said:

Ok thanks I figured that is what they were there for. I always winterize by warming the engine then running antifreeze through it while running. I've never had any issues even when I was in the northeast. Saves me from messing with those plugs.

That's how I winterize my boat

So you never pull the blue plugs when winterizing, you just leave the AF in the block?

aero3113 · October 2015

Yes, leave the antifreeze in. It's a good corrosion preventative.

Dream_Inn · October 2015

I agree, but you should pull the plugs once engine is warm before putting pink in. I used to do this all the time so it would prevent 'mixing' pink with water that is still in there. Now I use the manual air pump and then add pink.

Michael T · October 2015

I pull all the plugs and use the air pump. It doesn't take much water left somewhere to cost $$$$$ and as DI said you don't want to dilute the pink AF.

Cableguy Greg · October 2015

Why not use the -100 or -200 RV antifreeze after draining the block. If you pump enough thru the block, there should be more than enough to prevent a hard freeze. I agree with not diluting the pink stuff. I only use the pink for the fresh water system and use the -100 for the engine.

Michael T · October 2015

@CG you would probably be fine using the "green " toxic lol AF in your block. In the past I used to run AF through the block and left the drain plugs out until Spring but with my 2013 350 Mags and 2014 502 mags Mercury said to remove the blue drain plugs, use the Mercury drain system and blow air through. So I do and leave the plugs in a bag and re-install in the Spring. But what you are recommending, Greg, should be fine and makes sense to me.

Cableguy Greg · October 2015

@Michael T, there is an RV version of -100 that is made by Star Brite. That is what I was talking about. They also came out with a -200 as well.

http://www.wholesalemarine.com/starbrite-sea-safe-non-toxic-anti-freeze-100f-38191.html

howardrams · October 2015

Many ways to accomplish the same thing. I agree with what Cableguy Greg does. I use the non-toxic (blue) Mercruiser -100 intended for the engine because it has more lubricant and rust inhibitors than the pink. I use the -50 (pink) in everything else because it's cheaper and works fine. I see that some other companies now make the blue -100 for engines which is good because not everyone has the Mercury brand. It's ok to leave your plugs in as long as you make sure you circulate the AF through the engine long enough to fill everything after getting the engine warmed up.

Dream_Inn · October 2015

I definitely agree to leave the plugs in. Where I disagree is that you should pull the plugs after warming the engine up (for thermostat - I'm talking raw water cooled), then pull plugs to let all water out, put back in, and run pink/purple/blue in. I do this, but don't have to wait for thermostat since I'm fresh cooled (A/F already in my engine).

Michael T · October 2015

I agree 100% with you guys IF your engine is older than 2013. From 2013 on and with heat exchangers, Mercury has been pretty specific about what they want done to maintain your warranty. You test the antifreeze's specific gravity and adjust if necessary. Then you drain all "raw" water from the block using their new drain system by removing the blue drain plugs and the starboard ends of the heat exchangers and blowing air through the system. The blue drain plugs are left in a bag in the boat over the winter.

Dream_Inn · October 2015

MT, you saying you don't run any pink stuff thru your engines heat exchangers?

Michael T · October 2015

@DI - No they don't and we expect temps to be -30. Apparently you take out the blue drain plugs, pull the air pins at the front of each block and use the manual air pump to blow all of the water out of the raw water circulation system you keep pumping enough for the green pistons of the air pins to be visible until no more water shoots out, next you take the starboard end off each heat exchanger, then you check the SG of the coolant in the engine and if it's within normal range - that's it. Crazy eh? How times change! When I used to do it I always used to run a sh*tload of AF through the engine until it was blasting out the drives! :-)

Dream_Inn · October 2015

I guess mine is a mix between both old and new. I use my hand pump (like newer) until I see just air. Then I run about 3 gallons, maybe less, of engine pink stuff thru. Doing mine this Friday.

Michael T · October 2015

Probably safer DI. Guess the marina is trying to save money - it's on them if something cracks!

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