Drain Plug Removal question
Thread Starter
Drifting
Joined: Apr 2004
Posts: 1,716
Likes: 3,668
From: North Central Wisconsin & Shitcago
Drain Plug Removal question
On my 67 L79 I plan on removing the drain plugs to change anti-freeze. I rebuilt the engine fifteen years ago. Following the rebuild, the motor was painted. My drain plugs are the standard type and are painted over and have never been removed by me.
Any tips on the best way to remove these without destroying them? I do not plan on putting them back. In researching the forum, conventional wisdom seems to be to use teflon tape and replace them with petcocks commonly available from NAPA. I just seek guidance on removing the old plugs without doing damage. I also plan on using a philips screwdriver in the hole to clean out gunk and allow the old coolant to flow out.
TIA, Joe
Any tips on the best way to remove these without destroying them? I do not plan on putting them back. In researching the forum, conventional wisdom seems to be to use teflon tape and replace them with petcocks commonly available from NAPA. I just seek guidance on removing the old plugs without doing damage. I also plan on using a philips screwdriver in the hole to clean out gunk and allow the old coolant to flow out.
TIA, Joe
Race Director
Joined: Jan 2002
Posts: 15,354
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From: Close to DC
C2 of the Year Finalist - Modified 2020
I replaced mine about 30-35 yrs ago. Used a crescent wrench with good grip. Replaced with brass drain ***** with a small strip of teflon tape. 
Dennis
Dennis
Drifting
Joined: Jul 2005
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From: Putnam Valley, New York. Amateur Radio Operator K2NS
Drain Plugs
Use a ratchet with an extension and a 6 point socket---Less chance of slipping and rounding off the plugs. Soak them with some penetrating oil for a few hours before you begin.
RON
RON
Le Mans Master
Joined: Feb 2008
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From: NJ Hockey beer league
All of the above is good advise, chances are you won't gain anything removing those plugs since your block was as you say rebuilt 15 years ago I don't see that much build up. Petcocks are asking for trouble needlessly, the genius who posted that ............well never mind, it was part of his weekly tear down.
Race Director
Joined: May 2000
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Steel plugs are okay, brass is probably better. As stated use a 6-pt socket, and a bunch of extensions with and adapter to a 1/2" breaker bar and "shock" them open. Use pipefitter's "dope" on the threads, not Teflon tape, and don't crank them down hard. There is no spec for NPT thread torque other than tight enough to not have any leaks; 10-12 lb-ft is plenty with pipe dope.
The reason they seize is too tight installation without pipe dope.
Duke
The reason they seize is too tight installation without pipe dope.
Duke
