HELP! Freeze Plug Leak

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packin3deuces

packin3deuces

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:help: I started the Dart today and after pulling out of the garage noticed the 340 was dripping antifreeze below the oil pan. Shut it off, got under the car and found a small hole in the middle freeze plug on the drivers side. I have never dealt with freeze plugs before. Where can I get just 1 freeze plug and how do I replace the leaking one? Any advise is greatly appreciated. :salut:
 
A whole set of brass ones with galley plugs even can usually be had for around 20 bucks.
I believe I bought a whole set of them for that price on ebay.

But locally it shouldnt be a problem either.
 
Easy fix available at any auto supply,drain coolant(as much as possable)drain block too,you can drive one side of the old one in,sort of flip the plug in the hole.Then grab it with a pair of pliers and pull it out,clean the bore with scotch brite or similar add a little sealant to the new one(I like ultra black silicone)and use a large socket and hammer to tap the new one in to the same depth as the old one.Top up anti-freeze and go.
 
Quite often if one freeze plug starts leaking, others can't be too far behind. I do brass plugs in all my engines and never have to worry about them again.
 
65 Dartman is right, don't take any chances. Pull the motor out and replace them all, while you are at it degrease and paint your motor and it will not have any leaks and look like new!!!!
 
Once one goes, they rest are right behind, especially the ones in the back off the block... Get the brass ones from a discount boat supply- cheaper.
 
Tip....if you do pull it (which I agree you probably should) and replace them all.....use brass, but paint the block first and then install the plugs....the brass will expand and shrink and cause the paint to crack & peel down the road if you paint them with the block.

Rickster
 
looks to me someone painted motor and forgogot lil details lke replacing freeze plugs if you can replace all you can get too cause they are all in same shape
 
your local machine shop will have them. they buy in bulk so probably get them cheap.
 
Thanks guys for all of your help and advice. I really appreciate being able to learn from all of your experience. It allows me to make sound decisions moving forward. I can't believe an engine builder would use steel expansion plugs when brass ones are only a couple dollars more! :sign6: Oh well, I guess it's my problem now. :angry7: :banghead: Anyway, I'll take your good advice and replace all of the freeze plugs with brass ones. Tonight I went to Rock Auto's website and found the brass plugs, but they have several combinations of plugs with varying numbers of plugs in each set. How many freeze plugs does a 1971 340 block use? I can see 3 on each side of the block above the oil pan, but don't know what's hidden in front and in back. I want to buy the correct set the first time! Once again, any help is appreciated. :prayer:
 
Yep, they're all correct. The best thing to do is pull the motor and replace them all. If that is not an option, you can just replace the leaky one but don't be surprised if another one starts leaking soon. There may be more casting sand left in one side of the block than the other. You will be shocked at how much sand and sludge are in the bottom of the water jackets. Mike
 
If the plug is hard to get to and you want to do a quick fix get the rubber expansion plug to hold you over.
 
It's really hard to get to, next time use brass plugs.

probably have to pull it.

well...you could try and drain it then stick a mig wand in there and at low power weld it up.

but thats on you to decide, like others said...they all could be going.
 

1wild&crazyguy said:
It's really hard to get to, next time use brass plugs.

probably have to pull it.

well...you could try and drain it then stick a mig wand in there and at low power weld it up.

but thats on you to decide, like others said...they all could be going.
Click to expand...

As your name implies?
 
Today I was able to remove the leaking freeze plug and install a new brass one. I don't have the time right now to pull the engine and replace the remaining freeze plugs, so I'm hoping this repair will get me by for a while. If another one starts to leak, then I'll have no other option but to pull the engine. Once again, thanks to you guys for the knowledge imparted to me. Without your help, I would not have been able to do this. :salute:
1st photo is leaking freeze plug
2nd photo is after removal
3rd photo shows new freeze plug
4th photo shows the pin hole in the leaking plug
 
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