head bolt torque question

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Cav Trooper
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head bolt torque question

Unread post by Cav Trooper » September 26th, 2018, 4:28 pm

I am getting ready to bolt the head back on my a2. New head gasket with copper spray sealant. Since the bolts don't go into the water jacket, do I lube them like I would on a civiy engine when torquing them? Is one heat cycle enough for retorque?
thank,
CT

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rickf
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Re: head bolt torque question

Unread post by rickf » September 26th, 2018, 4:40 pm

Head bolts are never lubed, that completely throws off the torque reading and you will over torque them every time. Clean and dry. And be sure to run a bottoming tap into every hole all the way to the bottom to make sure they were tapped clean to the bottom. I have found several that were not and the bolts tighten before the head is torqued. One run cycle is good for the retorque.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

Fil Bonica
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Re: head bolt torque question

Unread post by Fil Bonica » September 26th, 2018, 5:05 pm

Before you do Anything, read pg 3-64 in 34-1 ,
Thereare specific instructions of what to do.


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Re: head bolt torque question

Unread post by Cav Trooper » September 26th, 2018, 8:32 pm

It helps if I have the right TM's. I did not have 34-1. Just downloaded it, makes it all perfectly clear. Thanks Rick and Fil.
CT

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Re: head bolt torque question

Unread post by rickf » September 26th, 2018, 9:30 pm

Interesting, I had to go and read it myself. They say sealer, not oil but why? They are blind holes. Sealer will not quite act like oil but will still change torque settings. Considering you are only going to 65 ft/lbs. it is not going to change much and they may have figured it in since the specify the sealer. But on most blind holes you do not lubricate the threads. I long ago gave up trying to figure out why the military does some things that make no sense and go against convention.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

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Cav Trooper
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Re: head bolt torque question

Unread post by Cav Trooper » September 27th, 2018, 11:32 am

Rick, that puzzles me too. If I use sealer, what type? Can't use silicone because of having to retorque, the silicone would be cured and if the bolts moved, the seal is broken. For pliable sealers, I have Indian Head gasket shellac, Permatex No.2, Permatex High Tack, Halomar, wonder which one?? Maybe chewing gum....

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Re: head bolt torque question

Unread post by rickf » September 27th, 2018, 5:04 pm

I use Permatex teflon thread sealant, it is made specifically for bolt threads in water jackets.

https://www.grainger.com/product/2GXY8? ... jgEALw_wcB
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

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