Block coolant drain plugs
Thread Starter
Burning Brakes
Joined: Sep 2017
Posts: 1,073
Likes: 65
From: Belgium
Block coolant drain plugs
Hey everyone
Do you guys know what the torque spec is for the two coolant drain plugs that go in the block?
It seems that they are conical (NPT). Do I have to use teflon onthese bolts or not?
The 77 A.I.M. doesn't say anything about these bolts.
Do you guys know what the torque spec is for the two coolant drain plugs that go in the block?
It seems that they are conical (NPT). Do I have to use teflon onthese bolts or not?
The 77 A.I.M. doesn't say anything about these bolts.
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
That "conical" description is why that thread is more correctly referred to as "Tapered"
Yes, you should use a thread sealer ... Teflon tape or "pipe dope"
I don't know a torque spec for that ... I just tighten a little more than "snug"
Those are usually steel and often seize VERY firmly due to corrosion ... often difficult to remove ...
... to limit corrosion ... many times are replaced with Brass. Often referred to as 1/4"-18 MNPT ...
... in USA, these are often found at local auto parts store, hardware store, plumbing supply
https://www.zoro.com/eaton-aeroquip-...4s/i/G2736614/
-addendum-
by now, you may've acquired a variety of sealers ... just about any will do for the above, so long as it does not truly become hard.
-edit
My mistake, .. thanks poster 75 is correct ... it is 1/4"-18
Yes, you should use a thread sealer ... Teflon tape or "pipe dope"
I don't know a torque spec for that ... I just tighten a little more than "snug"
Those are usually steel and often seize VERY firmly due to corrosion ... often difficult to remove ...
... to limit corrosion ... many times are replaced with Brass. Often referred to as 1/4"-18 MNPT ...
... in USA, these are often found at local auto parts store, hardware store, plumbing supply
https://www.zoro.com/eaton-aeroquip-...4s/i/G2736614/
-addendum-
by now, you may've acquired a variety of sealers ... just about any will do for the above, so long as it does not truly become hard.
-edit
My mistake, .. thanks poster 75 is correct ... it is 1/4"-18
Last edited by jackson; Nov 17, 2019 at 09:11 AM. Reason: wrong measurement
Le Mans Master
Joined: Dec 2007
Posts: 6,422
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From: McHenry Illinois
Thread Starter
Burning Brakes
Joined: Sep 2017
Posts: 1,073
Likes: 65
From: Belgium
I don't know a torque spec for that ... I just tighten a little more than "snug"
Those are usually steel and often seize VERY firmly due to corrosion ... often difficult to remove ...
... to limit corrosion ... many times are replaced with Brass. Often referred to as 1/8"-27 MNPT ...
... in USA, these are often found at local auto parts store, hardware store, plumbing supply
https://www.zoro.com/eaton-aeroquip-...2s/i/G1461266/
I cleaned up the original plugs with a wire brush. Now they are nice and shiny.
I will certainly replace them in the future.
In the book 'Rebuilding the SBC' by L. Atherton & L. Schreib they say 20 ft. lbs.???
Would that be O.K. or is that spec. overkill for these (steel) plugs?
Last edited by Novusuhu; Nov 17, 2019 at 08:53 AM.
Le Mans Master
Joined: Aug 2017
Posts: 8,336
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From: Cool Northern Michigan
Novushu, you must have a gold-plated torque wrench with diamond and ruby inserts that you just can't set down.
The most popular torque spec in the automotive industry is: Snug. Just like others have said. Don't worry about torque wrenches there.
Permatex makes a thread sealer which is safe for Glycol. I believe you already have a tube from an earlier post / project.
The most popular torque spec in the automotive industry is: Snug. Just like others have said. Don't worry about torque wrenches there.
Permatex makes a thread sealer which is safe for Glycol. I believe you already have a tube from an earlier post / project.
Last edited by HeadsU.P.; Nov 17, 2019 at 09:46 AM.
Thread Starter
Burning Brakes
Joined: Sep 2017
Posts: 1,073
Likes: 65
From: Belgium
Novushu, you must have a gold-plated torque wrench with diamond and ruby inserts that you just can't set down.
The most popular torque spec in the automotive industry is: Snug. Just like others have said. Don't worry about torque wrenches there.
Permatex makes a thread sealer which is safe for Glycol. I believe you already have a tube from an earlier post / project.
The most popular torque spec in the automotive industry is: Snug. Just like others have said. Don't worry about torque wrenches there.
Permatex makes a thread sealer which is safe for Glycol. I believe you already have a tube from an earlier post / project.
