I've noticed that a rear freeze plug is seeping ever so slightly, It has sealant (white teflon) around it as do all the others from what I can tell. However, there is a slight knick in the block where it appears to be leaking.

I Talked to the builder and he said I should just use some stop leak/alumaseal or some type of additive. Really have never used them in any of my vehicles. Anything to be weary of?

I do have an aluminum radiator if that makes any difference, can it be hard on water pump bearing or?....

I am afraid if I replace the freeze plug it probably will still seep or leak worse.

Thanks for any info, SS.

I would not put any stop leak in my motor. Pull the plug and find the problem.

K & W Block Sealer, available at most parts houses, has been around 30 + years and is a great product. I have used it numerous times and have recommended it many times and have always had good results. Never had or heard of any negative reports when using this product. It just plain works when used as directed. I would use it in this instance with no reservations.

You do not need block sealer. You need to pull that Welch plug and reinstall a new one this time with Balkamp-Permatex High Tack Gasket Sealant, NAPA part number BK 7651221.

Larger Dave

U have just spent good $s on a build...and before getting too far looking at patching up....not fixing...patching
Im with Dave

When someone tells me rear freeze plug, I think of rear of block, R&R transmission is required. Use brass plug with good sealer.

haha, somehow when someone tells me rear freeze plug, I think of the one that's not under the motor mount, side of block to the rear...

Which is it?

If it's the side, I'd yank the header and replace it. If it's the rear, I'd try the stopleak.

Hey Don, haven't heard from you on the Kansas City run, are you up for a roadtrip this year?

Wish I could , doing a local benefit that weekend then its tear down time. Will be down while sun is shinning and you guys digging out the drive way. I do hope this happens next year, I want to get out that way , some day , and see what the mid west is like.

The freeze plug is at the rear of the block the BH and trans are currently out.

What is the best method for removal?

I am not necessarily opting for the band aid fix (sealer).

My concern is the knick in the casting where it is seeping.

I would rather do it right thats why I was suprised when my builder suggested additive sealer .

Is pressure testing the system/plug after installation to check for leaks a good idea? Of course I will not be able to start and heat up the engine.

Any suggestions, SS.

I always either get a socket , prolly 1 1/8 ", and tap thru, it wont go too far, then grab the edge with a set of channel locks, Use the large curved jaw back as a fulcrum and pry out.
The other way is take a large screw driver or punch, tap a hole in it and insert screwdriver in to pry out.
Dont have to use a 10# hammer here, a 2# will work. Know your strength, Prolly driving a screw driver in and prying out would be best as if you are not careful , you will knock plug into jacket area and it may be hard to fish but can be done.

Clean hole sealing surface with some emory cloth or such, apply a coat of either, Indian Head Shellac or permatex 2 on edges and edges of deep 1 5/8 BRASS plug. Use selected socket and tap in til surface flush with block. Done deal. You can use red silicone if thats all you have, Hi tack sealer works well to. Just seal it. If you do have access to a radiator testor or such, filling with water and testing could be done but once these plugs are in and done right, thats the end.
Pat yourself on back or get some one to do it on a job well done.

Well, I had one that stopped seeping after about a dozen heat cycles. How long has yours been doing this?

And, Barr's leak is ok for stopping. You can do a search on it.

My seep was the one behind the motor mount and I wasn't going to mess around trying to R&R it. If yours is accessible I'd replace as others have suggested.

I'll second the recommendation for Permatex #2 as a sealler if there are slight irregularities in the sealing surface of the plugs.
If the 'nick' is large enough to clearly see with your naked-eye, then you need to evaluate if it needs repaired first to allow proper sealing.
I use JB-Weld ( http://jbweld.net/products/jbweld.php ) to make small repairs on these areas if necessary. Just mix a small amount and fill the area, allow to dry thoughly and then file/shape the profile to match the block area and your done - this repair will last until the block is 'hot-tanked' ...

You said the freeze plug had teflon sealer around it. That is certainly not a good choice for freeze plugs. Teflon is a lubricant. It's great for threaded fastner sealing and such, but a freeze plug you'll want to stick. If you put any sealer on your freeze plugs at all, use something like indian head shelac instead of a lubricating thread sealer.

Just caught a peak at the post above. JB-Weld might work well also.

Freeze plugs are a piece of cake to change if you can get to them. Change the leaky one if at all possible.

Not sure long it has been seeping, the engine has approx 1800miles on it. I just noticed while I had the clutch out.

I said white teflon but I think it is some other white sealant (pipe dope)? Screwdriver methods sounds like the ticket. I don't have access to a pressure tester as of yet but I need this thing sound by the 29th or I will be TSOL.

Thanks for the help, SS.

It could be white ARP sealing paste. It should be no problem, I know your concern when I changed my own the first time, under the motor mount. Pull it, clean the surface , apply form a gasket and tap it in. A 1 1/4 socket fits the outer edge of the 1 5/8 cup. A 1 1/8 fits the cup. Use the deep cup , which it probably already has. If you want to be sure on sealing, you can install flywheel only and crank, allow to heat and monitor and allow pressure to build, if you have the time. Once you feel satisfied, install bh and trans. I would not be afraid to do this either way. Still a few weeks from the 29th.

you can rent a pressure tester from most all parts store chains, i do say replace the leaking plug only takes 2 mins while the trans is out,,you should look closely at the block where that nick is at and make dang sure its not cracked,, but i will have to agree with 1962vette about K&W that stuff WORKS !!! i have used it a number of times and seen it seal some fairly large cracks,, Frank