[bhill86]

Can anyone help me out with the size of the square “head” needed to remove the oil plug by the distributor? Ordered a mechanical oil pressure gauge I’d like to plum there. I also picked up a 3/8 male npt to 1/8 female reducer. Does 3/8 sound like the correct size for there?

Thanks

[TxSportCoupe]

I believe you are correct.


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[Dragncar]

Most of hose are 5/16" square head. I have made a tool by grinding down a 1/2" grade 8 bolt to a 5/16" square. Some Craftsman punches are made of 5/16" stock, I have used those too.

[bhill86]

Thanks guys. Grinding down the bolt is a good idea. I think I should be able to come up with something like that

[lust4speed]

That 3/8" square recess pipe plug has had about 50 years to get comfortable with the block. Sometimes they are very hard to get out and sometimes they are really, really, hard to get out. I would suggest purchasing the correct size 4-sided easy-out and grinding the end down to where it fits snug when tapped into the plug recess. Once the plug is rounded off, you are done until rebuild time when you can drill through it and hammer in the easy-out -- so best to take it serious and give yourself the best shot of removing it.

There are vendors selling 5/16" socket adapters on eBay and such, but don't know if they are a good enough quality to survive. Then again, it just might twist right on out, and I've had a few that didn't have to be destroyed to get them out when stripping down blocks. Over the years I've split two Craftsman sockets on the easy-outs where the plugs put up a great fight.

[KEN CROCIE]

Snap ON ppm 410

[25stevem]

As stated these can be a Grisly Bear to get out since they are put in when the block is still hot from being cast.
To get a start on getting it out you need a big Ass punch that is fat enough to fill that 5/16” square hole and then beat on it with a good size ball peen hammer to stretch the the threads out and then spray some PB blaster rust buster on it and then beat on it again.

Then it will come out.

[sdbob]

I tried making the square adapter out of old 3/8 extension. Didnt work for ME! Wanted to round off the sharp corners of plug.even tried breaking sharp corners on extension. Bought the snap on adapter works everytime. Must be me,tolerances etc.

[MarkS57]

Originally Posted by sdbob

I tried making the square adapter out of old 3/8 extension. Didnt work for ME! Wanted to round off the sharp corners of plug.even tried breaking sharp corners on extension. Bought the snap on adapter works everytime. Must be me,tolerances etc.

This is what I did & added the beating Steve promotes; they came out...

[25stevem]

If you do not have a torch I find the Snap on socket to be mandatory!

[bhill86]

Thanks for the tips. I’ll give them a try

[sdbob]

I still have that extension in my tool box( probably tried this when I was 20).Everytime I see it I think I can make that work! Then nah getting too old to try.

[wbnapier]

I had the correct 5/16" square bit, but the plug rounds out. I had to hammer a chisel in, which had a hex shaft. Then I put an open end wrench on the hex shaft. That did the trick.

Good luck!

[hurryinhoosier62]

I bought the Snap On adapter probably 30 years ago. It works like a charm, once the appropriate amount of heat and penetrating oil is applied. I have used Kroil for years; it has never let me down.

[68WarDog]

PB Blaster soak x30 minutes. Then propane torch until red hot, through some more PB while red hot(stand back because the PB sometimes pop). Hit with the Snap on plug removal with a 3/8 impact, and it will zip right out.

[bhill86]

Sounds like a plan. I’m still waiting for the gauge to arrive and I ordered a 5/16 square so in the meantime I shot some PB Blaster on it to leave sit so hopefully that helps a bit. I’m also hoping since the engine has been rebuilt a few times it may come out a little easier. We’ll see. Worst case I guess I can run a T at the filter housing.

[Schurkey]

What good does penetrating oil do, when the whole point of a pipe-thread plug is to make an air-tight, leak-free seal via thread distortion?

The penetrant can't get between the threads to do any good. Makes a nice puddle on the ground, though.

HEAT the plug cherry red. Propane will not be hot enough. God bless Oxy-Acetylene.

The Snap-On pipe plug socket is not a perfect tool. The corners of the square are rounded-off; and the whole square is tapered. But at least the steel is hardened. My 30-year-old Mac version has no taper, and sharper corners, but the steel is so soft that the square twists right off. But the current Mac version is shaped differently from my old ones, (still not tapered, and with sharper corners than Snappy) they've been updated--perhaps the steel is better. No doubt MATCO and Cornwell and the Chinese Copycats have something similar.

https://shop.snapon.com/product/Pipe...Socket/PPM410A

https://www.mactools.com/products/xs104

Best replacement is to install a brass plug instead of steel. Pipe thread sealer very recommended to make a leak-proof seal with less torque than installing dry.

[chuckies76ta]

I wouldn't use any heat on it, but that's just me. You can always use the oil filter housing location and remove it someday when and if you tear it down. Just remember andycrap that falls down the hole from removing the plug, will and could end up in the lifters. The oil line I believe is the feed to the lifters, Cam bearings, Mains and rods. It would only take one little piece of dirt to plug the orifice on a lifter and that spells trouble.

[Sirrotica]

Originally Posted by Schurkey

What good does penetrating oil do, when the whole point of a pipe-thread plug is to make an air-tight, leak-free seal via thread distortion?

The penetrant can't get between the threads to do any good. Makes a nice puddle on the ground, though.

HEAT the plug cherry red. Propane will not be hot enough. God bless Oxy-Acetylene.

The Snap-On pipe plug socket is not a perfect tool. The corners of the square are rounded-off; and the whole square is tapered. But at least the steel is hardened. My 30-year-old Mac version has no taper, and sharper corners, but the steel is so soft that the square twists right off. But the current Mac version is shaped differently from my old ones, (still not tapered, and with sharper corners than Snappy) they've been updated--perhaps the steel is better. No doubt MATCO and Cornwell and the Chinese Copycats have something similar.

https://shop.snapon.com/product/Pipe...Socket/PPM410A

https://www.mactools.com/products/xs104

Best replacement is to install a brass plug instead of steel. Pipe thread sealer very recommended to make a leak-proof seal with less torque than installing dry.

^^^^^^^ This......

[bhill86]

Well, at least PB wont hurt. I don’t have a torch though so I’ll have to take a stab at it without.