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What Is The 'Right Way' To Install Freeze Plugs ?

288K views 26 replies 24 participants last post by  T-bucket23 
#1 ·
Hi Guys

Tell me please just 'WHAT IS THE CORRECT WAY TO INSTALL FREEZE PLUGS?

Either I hear DON'T USE SEALANT or YES, USE SEALANT.

Just what do you guys say about ' INSTALLING THE FREEZE PLUGS THE CORRECT WAY SO THE PLUGS DON'T
L E A K :sweat:

Let the games begin !

Seriously guys, whatever suggestions on the correct and proper way to install these little devils including: EITHER BRASS PLUGS OR STEEL will be GREATLY APPRECIATED.

GOD BLESS ALL YOU GUYS

Schooner :cool:
 
#2 ·
plugs

I have installed them about any way you could ever dream up and never had issues with them leaking...As long as there are no burr's in the hole and there is a small chamfer to start them... Some of the aftermarket blocks ( dart,world) etc do not have chamfers on them....


My process that i settled on and the way i do it now.

Make sure the hole is clean and free of defects

Coat the outside of the freeze plug with hi-tac ( from pematex) and install them...

keith
 
#4 ·
I can't count how many steel plugs I've seen that have rusted to the point of leaking. And I've had to replace a few on my own cars too. Brass plugs are pretty rare so saying I've never seen them leak doesn't mean a whole lot. Brass doesn't corrode like steel though and I've never heard of them failing due to corrosion. I use brass plugs unless they just aren't available.
I use Permatex "aircraft" sealer on mine. Just in case there is a small pit or something that might cause a tiny leak. If you have the engine out on the stand or something, freeze plugs are duck soup to replace. Once the engine is back in, if one plug is a problem it will ALWAYS the godawfulest worst possible one. The one behind the motor mount/exhaust/starter that you have to darn near pull the engine back out to work on. Never fails.
And you can't realistically "test" your freeze plug installs. You put them in, put the engine in, fill it with coolant and cross your fingers.
99% of the time you probably don't need any sealant. That last 1% is plenty enough reason for me. You can probably tell this particular dog has bitten me a time or two.
Whether just replacing a bad plug or replacing them as part of a engine rebuild, I only want to replace them once. I believe using brass plugs when possible and a bit of sealer increases my chances of not having to redo them.
 
#5 ·
Thanks For You Expert Imput Guys

HI GUYS

Here's what I finally did.
I bought the BRASS FREEZE PLUS and used this sealant called;
" THE RIGHT STUFF " :thumbup:
Bought it at: AUTOZONE, its expensive $13.00 bucks! But its worth it. I don't want ANY LEAKS :nono:

I cleaned the freeze plug holes in the engine block with brake cleaner and coated the hole with just the right amount with my finger.

Then I did the same just around the edge of the BRASS PLUG. With a large enough socket I tap-taped the brass plug into place. It stayed even all the way around into the engine block.

THANKS FOR ALL YOU IMPUTE GUYS. :welcome:
GOD BLESS

Schooner :cool:
 
#7 ·
freeze plugs

The machine shop near me that has been building race engines since the 1950's uses Brass freeze plugs and they use some sort of a shellac to seal them in. Kind of looks like that Indian Head stuff by permatex. Whatever it is, I know they use the same stuff around their cam bearings when they install the cam bearings.

My father had a brass freeze plug fail on him... in fact two at the same time on his 1948 ford coupe with a sbc 307. He couldn't really tell me what happened until he noticed the temp was going through the roof and looked behind himself at the coolant trail. He didn't build the motor and isn't much of a mechanic. So, I suspect it was due to an over heating issue, coupled with pressure. Blew both of them clean out of the block.

I took a look at the block when I was in town after that. I did notice some corrosion around the holes on the block. May have been possibly due to a bad sealing surface.

Make sure you clean the holes up before installing the plugs. Sand them smooth or wire brush them or whatever, then get the grease, oil, and other junk out of it before using any sort of sealant and driving them home.
 
#11 ·
Hey guys are there any alternatives to a leaking freeze plug that is hard to get to? I found a leaky one but it seems to be leaking from the outside of the plug where it meets the block (or the sealing surface). I really do not feel like pulling the engine out. Thanks.
 
#12 ·
SuperSport said:
Hey guys are there any alternatives to a leaking freeze plug that is hard to get to? I found a leaky one but it seems to be leaking from the outside of the plug where it meets the block (or the sealing surface). I really do not feel like pulling the engine out. Thanks.
You could try some block sealer....but anything you do other than replacing the freeze plug is just temporary.
 
#13 ·
SuperSport said:
Hey guys are there any alternatives to a leaking freeze plug that is hard to get to? I found a leaky one but it seems to be leaking from the outside of the plug where it meets the block (or the sealing surface). I really do not feel like pulling the engine out. Thanks.
The "right way" is to pull it and reinstall. But if you want to try a kluge fix first, green permatex penetrating threadlocker may work, it is designed to wick into the threads after installation. I don't think they do anymore, but in the 80s GM used to use this as a factory repair for a slow leaker.
 
#14 ·
GypsyR said:
I can't count how many steel plugs I've seen that have rusted to the point of leaking. And I've had to replace a few on my own cars too. Brass plugs are pretty rare so saying I've never seen them leak doesn't mean a whole lot. Brass doesn't corrode like steel though and I've never heard of them failing due to corrosion. I use brass plugs unless they just aren't available.
I use Permatex "aircraft" sealer on mine. Just in case there is a small pit or something that might cause a tiny leak. If you have the engine out on the stand or something, freeze plugs are duck soup to replace. Once the engine is back in, if one plug is a problem it will ALWAYS the godawfulest worst possible one. The one behind the motor mount/exhaust/starter that you have to darn near pull the engine back out to work on. Never fails.
And you can't realistically "test" your freeze plug installs. You put them in, put the engine in, fill it with coolant and cross your fingers.
99% of the time you probably don't need any sealant. That last 1% is plenty enough reason for me. You can probably tell this particular dog has bitten me a time or two.
Whether just replacing a bad plug or replacing them as part of a engine rebuild, I only want to replace them once. I believe using brass plugs when possible and a bit of sealer increases my chances of not having to redo them.
I have a 97 Ford Explorer 4.0L I need to change all the freeze plugs. Can I change them without removing the motor. Any advice.

Thanks Nonewcar Dog.
 
#19 ·
Morgan Inmany said:
Hi, My name is Morgan.
How to install Freeze plugs to the 1996 Toyota Tacoma 4X4. This plug was located on the right side of engine passenger side.

Thank you,
The methods and sealers are pretty well covered in this thread, as well as other threads here and on the interweb.

X2 on replacing them all if at all possible- if one went the rest are soon to follow in most cases.

I like to use a K-D seal/bushing installation tool to drive the plugs in, but a socket sized just smaller (like 3/16" less) than the plug's inner diameter so the driver isn't captured by the plug as it's driven into place, works as well.

I use either the brush-on Permatex or Permatex #2 from the tube as a sealant.

Getting the old plug out:

Much depends on how much elbow room you have to work with. This holds true on replacing the plug, too. Sometimes all that can be done is to use a rubber expansion plug.

Inside most engine compartments, there's precious little room to use for levering the soft plugs out from their holes.

A seal puller can be used if a hole or notch is made to hook the end into- but the tool is like a foot or more long.

You can in some cases, knock the plug into the water jacket (partially or completely), then grab an edge w/a channel lock and lever them out.

The rubber expansion plugs (use NO sealant, BTW) are tightened w/a wrench or socket on the nut/washer that causes the plug to expand, so if you can get the bad one out, you can use that to replace it- it will last a couple years- but if one has gone, the rest are not far behind, so get to them all ASAP...
 
#20 ·
Clean surface with die grinder. Tap it in with a socket of same size. Paint over with engine paint. Sealed. Brass does not matter. RTV or goo sealant not needed.

Knock it out tapping one side. The plug will turnstyle and then you can pull out.

Depends on how much room there is to work. A guy used a 90 deg electric hammer thing from craftsman to knock his head freeze plug in behind the firewall.
 
#22 ·
I've always had the machine shop install the new plugs when they finished the machine work. My shop always uses brass plugs, and some sort of black sealer I see around the plug. Never saw a reason to do them at home, as the cost of having them done at the shop was so minor.
 
#24 ·
cobalt327 said:
The methods and sealers are pretty well covered in this thread, as well as other threads here and on the interweb.



I like to use a K-D seal/bushing installation tool to drive the plugs in, but a socket sized just smaller (like 3/16" less) than the plug's inner diameter so the driver isn't captured by the plug as it's driven into place, works as well.

I use either the brush-on Permatex or Permatex #2 from the tube as a sealant.

I agree, I have used sockets in a pinch and they work.One problem is that the socket can deform the plug and shrink the diameter if the center is caved a little from beating on it. I am guilty of doing that I openly admit, in my younger days. Any of the sealers mentioned here work well,red loctite is and anerobic type medium that hardens in the abscence of air so it will "cure" after being installed. It is what I use.It will also tend to grab the plug and basically Glue it to the bore so it wont pop out.
One thing to remember is that Freeze plugs as they are more commonly referred to here are actually called "welch plugs". as they are the spot in the sand mold that supports the sand while the block is being cast in the foundry. After it cools the sand is removed it leaves a void in the casting or a "welch" where there is not material as the sand was used in that region for supporting the mold.It is then machined concentrically to accept a "welch plug". Just thought you might like to know.( not you cobalt) ;)
 
#25 ·
Core plugs, frost plugs, freeze plugs, soft plugs, welch plugs, expansion plugs, those danged rusted out leaking plugs- it's all good.
latech said:
One thing to remember is that Freeze plugs as they are more commonly referred to here are actually called "welch plugs". as they are the spot in the sand mold that supports the sand while the block is being cast in the foundry. After it cools the sand is removed it leaves a void in the casting or a "welch" where there is not material as the sand was used in that region for supporting the mold.It is then machined concentrically to accept a "welch plug". Just thought you might like to know.( not you cobalt) ;)
Yeah- me too! I never knew the void left from the sand being removed was known as a "welch". So that's cool!
 
#26 ·
I worked on a diesel engine assembly line and a large stationary engine assembly line. Both used the gooiest dark blue Loc-Tite sealer I've ever seen. Don't get it on your hands...it will be there forever.

The diesel 'freeze ' plugs were installed automatically...except the ones that the machine missed. The big engines were installed by hand with special drivers.

Heat resistant sealer and square to the hole are criteria.
 
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