Leaking freeze plug on 67 383

OneEyed

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I've got a leaking freeze plug on the passenger side of my Newport. It's not bad by any means. But it smells terrible. I'm worried about driving it and it blowing out completely.

Any suggestions?

It's roughly between the center two spark plugs. Not sure if it's possible to replace without removing a bunch of stuff...
 
I've got a leaking freeze plug on the passenger side of my Newport. It's not bad by any means. But it smells terrible. I'm worried about driving it and it blowing out completely.

Any suggestions?

It's roughly between the center two spark plugs. Not sure if it's possible to replace without removing a bunch of stuff...

These plugs are a major pain in the butt to change. I would be inclined to try the following temporary fix since the leak is small:

1.) Drain all of the coolant out of the block.
2.) Clean out the recessed part of the soft plug with brake-kleen or some other good solvent to get rid of accumulated grease and dirt. Take care not to make the leak bigger with over aggressive cleaning. Satisfy yourself that the leak is not coming from the sealing surface of the plug but from a rust out in the center area of the plug.
3.) Buy yourself a tube of hard drying permatex gasket sealer.
4.) Fill the recessed part of the plug with the permatex and let it dry overnight.
5.) Refill with coolant.

This is a cheap and quick fix for small leaks that will usually last for some time. Keep in mind that your other soft plugs are probably not far behind the one that is leaking, so keep up your anti-freeze density to at least -20F to control further rusting.

Hope this helps.
Dave
 
Leaking freeze plugs can blow out where they are rusting though. There 2 freeze plugs on either ride of the center exhaust ports if it is a big block eng. Recommend you pressure test to confirm location. Always replace if possible
 
Leaking freeze plugs can blow out where they are rusting though. There 2 freeze plugs on either ride of the center exhaust ports if it is a big block eng. Recommend you pressure test to confirm location. Always replace if possible

Agreed that it is always better to replace. Most of the time, steering linkage will have to be removed to get it out of the way. Once that is done, the next trick is to get the replacement plug lined up straight in the hole so that it will properly seat. Certainly not impossible, but a major pain given the lack of room to work. Cal-Van used to make a specialty driver for installing freeze plugs that had a series of slugs that fit inside of the recessed area of the soft plug and attached to a driver shaft so that the plug could be driven in. These worked well where there was room to work.

As a last resort, there is also an after-market plug that is made out of rubber. These have a hex-nut on the outer surface that is tightened to compress the rubber part of the plug and make it fit tight in the hole. I tried these and found that they tended to work loose and blow out over time so I do not use them anymore.

Dave
 
For what its worth, I have used the rubber expanding ones in two spots that were too difficult to drive a metal one in straight, and had good luck with them.

I'm not sure if your leaking one is in the head or down in the block? At least one of the ones in the block will not accept the rubber type. It hits something inside the block before it is completely seated.
 
Dorman makes a copper expanding plug that should work well for you. I know there are boat motor builders that use these on new builds.

Dorman Products - 02483

02483-001.jpg

02483-007.jpg
 
I replaced all my freeze plugs in both heads recently.

They are hidden behind the headers, so the headers needs to be lifted. And as said, little room to knock the new ones in place.

The trick turned out to be to remove the inner fenders (!). That allowed direct view and access from the wheel houses. Took 20 min to remove (front fenders still in place) and an hour to put back.
 
Your soft plug is not properly seated, that is why it is leaking.

Dave
Thats why I am trying to find a replacement. I can either buy them by a specific size or I can buy a set for a 383. But I can't actually find what size that hole in the picture needs. Id like to try the Dorman that was pictured above since it looks like I dont have much room to install the "press in " kind.
 
I'm 99% sure it's 1 5/8" which means the part number I posted will work. Permatex #1 or #2 will work as a sealant.
 
I mashed in some aluminum foil and made my best attempt at getting a rough measurement. So it looks like my 1.5" inside would agree with you, thanks!

Just wanted to clarify also, this is a block plug. I found the head plugs are located between the spark plugs and this leaked is well below all that.

Thanks for the help, gonna order a few plugs tonight! Better have a spare or two..

20170724_174236.jpg
 
So got the Dorman plug installed with the #1 goop. Before, I cleaned all the old gunk out of the hole, used fine sandpaper and brake clean also. Applied plenty of goop and tightened it according to the instructions. Once I was satisfied I noticed that's it's a little crooked. One side seemed to drop in a little further than expected considering it fit flush during the dry fit.

Will this be a problem or is it a wait and see kind of thing?
 
The instructions said not to loosen it once it's been tightened. So i didnt want to try to reseat it. But I did buy an extra one..
 
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