Jump to content

Question on freeze plugs?


51Meadowbrook

Recommended Posts

Ok so I'm driving down the road and my temp gauge wasn't working properly and did not realize the engine that I recently rebuilt over heated causing the rear side freeze plug to pop out! Luckily I had a spare in the trunk and installed it. Turns out the belt had come off causing it to over heat . My friend Tony who is a mechanic and fabricator asked me if I had put all the new freeze plugs in properly because he thought that the hump side of the freeze plug should be facing out so when tapped in it would put pressure against the edge of the freeze plug hole. So my question is which way should the freeze plug be facing when installed hump side in or out?? 

Link to comment
Share on other sites

Hump outward....use a large flat heavy driver and carefully slightly flatten the hump. Clean the plug seating area well and use sealer like permatex # 1 or I use JB weld.

Soft Plugs Flathead  (6).JPG

Core Plug Installs (3).JPG

moparflatbrasscupsoftpl.jpg

Edited by Dodgeb4ya
  • Like 2
  • Thanks 1
Link to comment
Share on other sites

Above information is correct. When you slightly flatten the hump in the center of the plug, it increases the diameter of the plug, thereby wedging it in the block. If you have not installed your plugs in this manner, do not drive the car until they are installed correctly. I'm sure you do not want to damage the engine.

Link to comment
Share on other sites

11 minutes ago, captden29 said:

not sure JB weld is good as a sealant.too permanent, maybe? i use a product called boatlife. it is typically used in marine application for watertight seals hardens  , glues, seals, but can be easily removed.   capt den

Concur that JB Weld is not a good idea. Just use Permatex or equivalent.

Link to comment
Share on other sites

I have used JB weld on all Mopar engines that had pitting in the recess...and on all shallow or shallow cup plugs for years. Never a leaker.

Another reason is to help prevent soft plug blowout on high performance Hemi's....I have seen them being blown out at high RPM. Not much of a recess on those old 331/354's.

I've never had a problem. They remove OK too.

I cannot have come backs!

  • Like 1
Link to comment
Share on other sites

the key word in jb weld is "weld". these plugs should pop when needed. this is not a hemi engine. if jb weld works for you, that's fine. a sealer like permatex will definitely make any removal later much easier, especially with the engine in the car. i use jb weld for permanent fixes. good product.   capt den

Link to comment
Share on other sites

And people think JB Weld is just that! not so...

Link to comment
Share on other sites

    This is going to sound like a"cob job", but here goes!

    In 1992, after having just restored my air-conditioned big block Barracuda, I noticed an antifreeze leak coming from the back of the right (passenger side) cylinder head. Upon further examination, I found that I had a pin-hole in the welch plug on the firewall side of the head.

    Normally, I like to make proper, correct 'generally accepted' repairs. Unfortunately, I had committed the car to a couple of immediate events. A buddy suggested building up a thin layer of JB-Weld on the plug itself. So, I layed down three thin coats over the pin-hole, not effecting the surrounding sealing area. My plan at that time, was to eventually pull the top of the motor off, pull the head and replace that welch plug.

    I never got around to it! That "cob job" repair is still doing fine after TWENTY-FIVE YEARS! Since then, I've done the same thing on two other hard to reach plugs, with the same positive results.

Walt           

Link to comment
Share on other sites

45 minutes ago, Dodgeb4ya said:

And people think JB Weld is just that! not so...

Interested with this topic, I'm getting ready to install new brass freeze plugs in my block I just got back from the machine shop. I also plan to use some sort of sealer.

Link to comment
Share on other sites

Had a freeze plug pop out after a new engine rebuild. It was the rear one on the driver's side. I replaced it by ginding a ball end on a fourt foot piece of 3/4 inch rebar. Had a freind hold it off the newly painted fender and I hit it soundly from outside the car with at 3 lb hammer. Still holding. I now carry a couple of the screw in metal freeze plugs in the trunk. I didn't know these existed but O'Reilly's ordered them for me. Hope I never use them. 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.

Terms of Use