Freeze Plug Blues

[podracer169]

Greetings all!

Beautiful weather out here in the NW this weekend. Spent some time working on my BT7 in the hopes of completing the restoration before summer arrives. I was going to make final adjustments to the carbs so I fired her up and got her up to operating temp. I noticed that there was a small puddle of water underneath the car. Traced it to the rear of the motor just underneath the head. I wanted to find the exact source so I pulled the tranny tunnel and the extension panel. I was able to see a small amount of water weeping from the freeze plug on the block. ****! I’m so frustrated and do not like the thought of having to pull the motor out to replace an $0.08 part. I do have great access to the plug so my question to the group – has anyone ever replaced a freeze plug (aka core plug) while the motor was still in the car? The motor was completely re-built 3 years ago and never really ran for more than a few minutes until now.

Any suggestions or comments are greatly appreciated.

Steve

 

[jlaird]

Clean up the plug and around it and use some of the paste epoxy till you pull the engine next time.

Use to do this all the time long ago.

 

[podracer169]

jlaird,
That was a quick response - thanks!
Would you suggest something like a JB weld? Is that the paste epoxy you are referring to?

 

[Dave Russell]

Hi Steve,
It isn't very hard to replace the plug. Since you already have the extension panel off, you have a somewhat straight access shot to the plug. Drill a small hole through the plug, tighten a sturdy sheetmetal screw into the hole, use a nail puller pry bar against the screw head & lever the plug out. Clean the plug seating surfaces well, apply a good permanent type sealer to the new plug & seat it in the block. It should be the cup type plug, drive it in with something that is a little smaller than the ID of the plug.

Actually, the expanding rubber "temporary" plugs have been known to hold for years & don't have to be driven in. I would certainly trust this plug more than trying to seal the leaking plug. See the attached pic.

Most plugs that leak show a small rusted through pin hole. It wouldn't hurt to carry spare rubber plugs of the appropriate size, just in case another one happens to let go.
D

 

[podracer169]

Dave,
This makes me feel much better! I will go the route of a replacement plug and see how that goes. Thanks again for the reccomendations!

Steve

 

[zblu]

There are s/s core plugs available, have used them on other motors, but make sure what you get is imperial not metric close enough!

 

[podracer169]

Freeze Plug Blues - sizes

Looks like there are two sizes used on the block - 1 5/8" or 1 5/16". The one I need to replace is 1 5/8". I'm assuming someone like Moss carries the correct plugs. SS would nice. Any reccomendations on what to put on the plugs when installing them (some type of sealant)?

Steve

 

[Dave Russell]

Re: Freeze Plug Blues - sizes

Hi Steve,
For core plugs, I prefer a hardening sealer such Permatex #1. Your local auto parts store likely has the right size plugs.
D

 

[podracer169]

Thank you!

You guys are great! I really appreciate all the advice and help. I'll post the results once I'm done - should be fun.

Steve

 

[Richard Dickinson]

Re: Thank you!

I have used the expandable rubber plug in an inexcessable place and it lasted for years.

 

[podracer169]

Popped out the old one

I easily popped out the old freeze plug last night with a slide hammer and screw. The plug actually looked in great condition so I dont know why it would leak. Picking up a new plug today and some Permatex #1 so I can press it in tonight. I think I'll let it sit for a couple days before testing.

 

[Dave Russell]

Re: Popped out the old one

If you don't like the idea of rubber plugs, another type of all metal core plug that is made by Dorman, can be tightened into place with a wrench. These have been known to last for many years. See attached pic.
D

 

[Keoke]

Re: Popped out the old one

YepDave, and they make one with a bronze top and bottom that should follow you to the grave.---Keoke- /ubbthreads/images/graemlins/grin.gif