1973 Dart 318 core plug replacement questions

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Lasalle

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The core plug on the right/passenger side rear next to the oil filter is leaking. Questions:
1. Can this be replaced with the engine in the car?
2. Should I get a steel or brass replacement?
3. What size is correct?
4. Should I use sealer? If so what kind?
5. Will any auto parts store have this part or will I have to order it somewhere?

Thank you, Tom
 
Unless it's a special block it should just take the standard old core plug for a 318. Go to Napa or AutoZone or O'Reilly's and tell him you need to get a freeze plug for the side of your 318 block. Pop the old son of a gun out and drive the new one in. I like to paint mine with a couple coats of engine paint before I drive them in and let the paint act as a sealer.
You might notice a bunch of rust and crud behind the freeze plug once you pop it out. You need to flush that out that's one of the reasons your plug failed on you.
 
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It sounds tough if you never did one. Use a socket about the same size and either paint or rtv. If one is leaking then the rest are close Togo. I like to pop them all out. Flush the block with a hose and relieve the 40+ years of debris out. Let it dry and lightly sand the flat surface so the new plugs don’t fetch up on any thing.

Also spend the extra and go brass. You will end up with more plugs left over if you buy a kit but typically a kit is cheaper than the individual block plugs.
Good luck!
Syleng1
 
Lasalle said:
The core plug on the right/passenger side rear next to the oil filter is leaking. Questions:
1. Can this be replaced with the engine in the car?
2. Should I get a steel or brass replacement?
3. What size is correct?
4. Should I use sealer? If so what kind?
5. Will any auto parts store have this part or will I have to order it somewhere?

Thank you, Tom
Click to expand...
1. Yes
2. Brass
3. Get a kit
4. Yes. I like CopperCoat, but, Permatex, rubber cement, or even paint will probably work ok if the hole is clean and smooth.
5. They should all have them individually, but, a kit might have to be ordered.
6. If all your freeze plugs are steel, do yourself a favor and change them all. It's a big, messy job on a small block since you have to pull the transmission to get the rear ones, but, in the long run it will save time, money and agravation.......not to mention possibly saving an engine from overheating. Flushing out the block of rust and debris is probably the messiest job you will ever do.
 
Thank you for your responses.

A. With the engine in place, Is there enough room at the back right side to swing a hammer to remove the old one and install a new one?
That is my biggest concern.

B. What is the mopar part number for the replacement core plug? I gave some thought to getting an NOS one but that may be more trouble finding than it's worth for something hardly seen.
 
They make an installation tool for freeze plugs. Might not be cost effective for just an occasional need though. Extensions of various lengths and types along with a socket just a bit smaller than the I.D. of the freeze plug will usually get the job done. The factory plug is a steel one....forget that. Get brass.
 
Here's a thread from long ago,with some good info, and a pix of the extension I use for replacing plugs.
Good luck .

www.forabodiesonly.com

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Well the big came to start the engine...when we added the water, it started to pour out over the floor. With a quick inspection, we seem to have lost 2 frost plugs when it was stored outside last winter. We checked with the company that did a mechanical break in and they don't all water. Very...
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If you're doing this in your garage or driveway with car up on stands, be prepared for some nasty, rusty coolant raining down when you pop out that plug. You can try to drain the system all you want and even pull out the block plug, but, once you knock that plug loose, prepare for a shower. I use a BIG screw driver that I hammer into the bad plug to pop it loose. Then pry it out, flush the block, and hit the hole with some sand paper or crocus cloth. Let it dry, then coat the hole and new plug with a thin layer of sealer. Drive the new plug back in to where the outer lip is at least flush with the block.....or even better, ever so slightly further in. Refill with coolant, check for leaks, and then go take a shower! :lol:
 
In the 1 5/8" 1.625" size there are shallow ones and deep ones. Which one is the right one?
 
I also use a big screwdriver and a pair of channel lock pliers.
I drive the screwdriver into the plug. **** it sideways. Then grab it with the channel locks and pop it out.
If I don't put a couple of coats of paint on the new plug, I use Indian Head gasket shellac.
Don't overthink this. You don't need OEM plugs. That's what failed. Get brass replacements.
Do not get the flat freeze plugs. Get the cup shaped plugs.
As said flush out the crud. Emery cloth or crocus cloth the hole in the block. Then I usually spray paint the opening.
Time to drive in the new plug. I use a big socket and hammer. If you get started a little cockeyed don't panic. Just tap on the other side of the socket to straighten it up.
 
There were shallow cupped plugs and deep cupped plugs in the 1 5/8" size. I ordered one of each in brass.

The OEM original steel ones lasted 50 years. I'm going to attempt to replace just the leaking one for now with the engine in place. I was really caught by surprise that I might have to pull the engine to replace deteriorating core plugs when this leak popped up. I guess I have to plan on that in the future when the other ones start leaking. My last two leaks on this car are a core plug and a rear main seal. I already fixed a leaking water pump, leaking power steering box, and leaking transmission.
 
Lasalle said:
Thank you for your responses.

A. With the engine in place, Is there enough room at the back right side to swing a hammer to remove the old one and install a new one?
That is my biggest concern.

B. What is the mopar part number for the replacement core plug? I gave some thought to getting an NOS one but that may be more trouble finding than it's worth for something hardly see
Click to expand...
4556022 mopar part
 
Success! I changed the leaking core plug today. It turned out easier than I thought it would be. I thought I would have to beat on them to remove and install but they only required medium taps. I am changing the rear main seal also so I had to remove a bunch of parts to get the pan off. That made access to the core plugs easier.
Thanks for your help !!!!
 
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