Maybe I'm crazy, but I've never heard of a rubber freeze plug.

I wouldn't think that a rubber plug could resist the heat and pressure.

Think about going to another shop.

- Brian

 

I'm a mechanic and I've never heard of such. I unno bout that...

 

I would have accepted it with the caveat that you find the right plug (dealer?) and they put it in n/c.

Rubber freeze plugs sound as usefull as a screen door on a submarine.

 

After some research and asking around, it seems that pretty much only southern mechanics have ever heard of rubber freeze plugs. They are pretty much not used in the north because of the extreme cold temperatures that render them pretty useless. Here in Georgia, the lowest it gets in winter is MAYBE 30 degrees, with most of the coldest days being around 40. They are able to be put in without removing the block, and they withstand the pressure of the coolant system. Although rubber, they feel extremely hard, almost like an incredibly hard plastic. I had no idea that no one would have heard of them.

The reason a rubber freeze plug was put in was because they couldn't find the original freeze plug, even at the local Chrysler dealer.

 

Some donkey put a rubber freeze plug in my 4.0. Noticed coolant pouring out of my block the other day and I replaced it over the weekend with a brass plug. Nearly lost my sh*t when I saw that it was rubber. Come on! Common sense? Maybe this flies south of the macon dixon, but for those of you that live anywhere above the frost line, do yourself a favor and get the brass plugs. Also, lots of instances of block heaters (also with rubber plugs) also leaking and/or blowing out. Just do your research.

 

I prefer solid metal plugs but,
um, rubber freeze plug is made of a medium hardness rubber and has a nut on it. When you tighten the nut it expands the rubber against the hole. Then the inner rubber expands and it locked in tightly. The only way it could come out is if the nut comes loose or the rubber fails or it is the wrong size rubber plug for the hole or If the block freezes solid. I have only used them twice in my life and they held fine. they would be better than a loose fitting metal plug.

 

how could you not find the correct freeze plugs? there's only a few basic sizes of plugs in all motors...

 

freeze plugs are available for I would bet, every vehicle on the road.

Get a new mechanic.

what year of Jeep and engine size?

 

I used rubber freeze plugs, (expansion plugs), in a 350 SBC when I lived in Colorado. Never had a problem. They hold up just fine.

 

I used one on my CJ's old engine here in Colorado. Tightened it up about 6 months after installing it, but never had any issues.

It was either that or remove the following to install a brass one:
-steering column
-intake manifold
-exhaust manifold

I took the route that took about 2 minutes and have no regrets.

 

Im from Georgia and I have been turning wrenches for quite some time and I have never heard of a rubber freeze plug. You must be from south Georgia. Its getting 28* tonight but for the most part we do only get mid 20s for the lows here in Macon.

 

Freeze Plug - Rubber Expansion by Motormite - Part 02605 - Advance Auto Parts

If the block freezes, I think a rubber plug would be harder for the ice to move than a metal plug.

So were freeze plugs really designed for freezing or are they just casting plugs for cleaning access to the water chamber.
I mean will a 'freeze' plug really keep the block- head from cracking?

 

yep that's what there designed water expands when turning to ice so the excess force pops the plugs out instead of cracking the block,

 

AUTO,TRUCK FREEZE PLUG, CAR COOLING SYSTEM REPAIRS BY ECONOMECHANIX

found this, claims blocks can crack anyway. I had 2 engines freeze on me, and they survived by popping out the plugs. Not all the plugs came out.

a video showing a poorly fitted freeze plug. Some of these plugs come in fractions of 1/64th inch.

 

Isn't the opening filled w/ a freeze plug something needed in making the original casting of the block ?

 

Yea the freeze plugs are actualy for casting purposes to romove excess sand after the casting problem, as well as for when your motor freeze they are suppose to pop out. But sadly most METAL ones seize and corode or rust, and don't do there job. Which is why they have rubber ones. If installed corectly they do there job. And in your case usualy if a motor over heats the holes where the freeze plugs go sometimes warp. So rubber is usualy a better idea. I've installed them in a few motors and never had an issue. And for those who commented saying they should have freeze plugs to fit it, that is wishfull thinking on your part I run a fleet and when it comes to older vehicles it's is extreamly hard to get such specific parts alot of times. Which is why they make ruber expandable ones.

 

Hi, I have never heard of the rubber plugs...can they be installed without removing the metal leaking one?

 

I replaced a leaking freeze plug with one of the rubber ones recently, due to the location being really tough to re-install an OE metal one. The rubber one now leaks worse than the corroded metal original one. My jeep has been sitting for 2 months now, often times in single digit temps, and I don't think it has much in the way of coolant left in it. It's all over the parking lot instead...

 

I have seen the nuts rust so maybe good idea to oil the nut & bolt before you put it on. Then you can tighten later. It is like a rubber hose, clamps need periodic tightening. likely same with rubber plugs.

 

They are casting plugs, the term freeze plug was coined by an extremely lucky idiot.

 

Well they call the plugs freeze plugs for there purpose of being there. And the whole is actualy a casting hole for wash out after production of the block

 

It's a personal decision

 

where i live it gets pretty cold. can get down below zero here. i had a full size chev. truck once where the freeze plugs rusted holes in them from previous owner lack of antifreeze. i replaced the ones i could with steel and one in particular was very hard to get to so i replaced it with a rubber plug. it was supposed to be a temperary fix until it came loose but it never did. three years later i blew the motor but that plug stayed strong with no leaks. i personally say they work.....they dont cost much.......and in a pinch are a very hard to get to spot they work. but on the other hand i did that to my own truck. would not expect that from a shop......

 

As posted before, "freeze plugs" are metal discs used to seal the holes left by the casting process to hold the engine cores in proper alignment. They will not protect a block from cracking due to freezing temperatures.

 

that is one of there functions is to pop out when the water frezzes In a motor. I am a ASE certified mechanic and run a fleet of 47 vehicles so I'm pretty sure I know what they are there for.

 

Being a boater I have seen quite a few engines that were not winterized correctly and the water in the block froze. Once in a while the casting plug will push out without cracking the block but it is certainly not common. I am amazed at the sheer number of people who actually think this was part of the design of the block.

 

Like they guy above you...Lol.

 

someone please show me where car manufacturers actually say they make these "freeze plugs" for keeping an engine from cracking? they are designed for casting purposes only and though they work to keep the block from cracking they are not designed for this purpose. if they didn't need the "access" holes in casting there wouldn't be any holes like that on the block. and not to poke back at other users but I am also a ASE certified technician, I have a degree in automotive technology and have done a fair share in machine shop work.

back on topic
never heard of rubber ones but I guess they work. would use them in a pinch if I needed too.

 

Well I suppose that's the difrence in were you learned what you did. Just because you never heard of them being used or designed in for that purpose doesn't mean it isn't true. It just means you are un aware and not wanting to accept it as a truth.

 

I used one on my old car instead of having to pull the motor to put a metal one. They work well, but you have to replace them every year or so.

In my case it was the easiest fix and I was damn glad they make them.