Hi-Temp Thread Sealant Question

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Divenut

Divenut

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Hi Folks,

Putting parts back on my 340 and am looking for some input/suggestions on the best type of Hi-Temp Sealant to apply to the front & back header bolts. Want something that will prevent coolant leaks, while still allowing me to easily back the bolts out in the future if needed.

Considering either:

Loctite 592 PST Thread Sealant High Temperature

OR

Permatex 230-59235 High Temp Thread Sealant

Your thoughts???

Thanks as always,
Pat
 
Thanks for the quick replies! You guys all rock:headbang: I'll pick some up at lunch.

Have a great day fellas,
Pat
 
I use the liquid Teflon myself too. Never had a leak. If you need to repair the hole threads in the head, make sure the helicoil is also sealed to the head.
 

I've seen the liquid teflon bubble up and drool out of exhaust stud holes before, that's why I stopped using it.
 
I never had that issue. I just hate cleaning up the RTV when you pull the bolts for something...lol.
 
moper said:
I never had that issue. I just hate cleaning up the RTV when you pull the bolts for something...lol.
Click to expand...

When I worked for GM, that's what they recommended to seal bolts. I used it on head bolts, exhaust bolts, you name it. Just like GM recommended. Then, we noticed on some things coming back. Such as coolant migration through head bolts. Course Chrysler motors don't suffer that malady, but the hot coolant actually melted the teflon sealant and migrated UP into the rocker arm area. There were actual TSBs on it. Damndest thing I ever saw. Coolant defying the law of gravity. Really strange, but it was happening.

Also, as I said earlier, I have seen it used on exhaust bolts....on a Mopar and just like I described, it boiled out and drooled down the side of the head......instant coolant leak.

Now, maybe teflon sealant has evolved, I don't know. But, I've been using sensor safe high temp silicone on head bolts ON THE LINE at dealerships as the head engine man literally 25 years.....with narry a problem. It doesn't affect the torque spec enough to worry about and it seals like a **** and keeps coolant (if the bolt holes are not blind) and oil from migrating into the threads. Also, I've never had a problem with it boiling off the exhaust studs.

But hay, like I've said many times, what doesn't work for me, may well work awesome for somebody else. We all do things different...that's just what's worked for me.
 
StrokerScamp said:
When I worked for GM, that's what they recommended to seal bolts. I used it on head bolts, exhaust bolts, you name it. Just like GM recommended. Then, we noticed on some things coming back. Such as coolant migration through head bolts. Course Chrysler motors don't suffer that malady, but the hot coolant actually melted the teflon sealant and migrated UP into the rocker arm area. There were actual TSBs on it. Damndest thing I ever saw. Coolant defying the law of gravity. Really strange, but it was happening.

Also, as I said earlier, I have seen it used on exhaust bolts....on a Mopar and just like I described, it boiled out and drooled down the side of the head......instant coolant leak.

Now, maybe teflon sealant has evolved, I don't know. But, I've been using sensor safe high temp silicone on head bolts ON THE LINE at dealerships as the head engine man literally 25 years.....with narry a problem. It doesn't affect the torque spec enough to worry about and it seals like a **** and keeps coolant (if the bolt holes are not blind) and oil from migrating into the threads. Also, I've never had a problem with it boiling off the exhaust studs.

But hay, like I've said many times, what doesn't work for me, may well work awesome for somebody else. We all do things different...that's just what's worked for me.
Click to expand...

Where can a person buy the sensor safe high temp silicone?
 
Well any cooling system coolant is under pressure at running temps so it will go anywhere it can. And the modern engines that's 17psi or more of cooling system pressure with poor seating/improper construction head gaskets. I've been told by factory reps it also used to be a "line" procedure to drop in a tablet of Bars Leak in the cooling system in every new car - I was told all Big 3 did that back in the 70s and 80s just to combat the little pesky seaping leaks that eat up warranty money.
 
moper said:
Well any cooling system coolant is under pressure at running temps so it will go anywhere it can. And the modern engines that's 17psi or more of cooling system pressure with poor seating/improper construction head gaskets. I've been told by factory reps it also used to be a "line" procedure to drop in a tablet of Bars Leak in the cooling system in every new car - I was told all Big 3 did that back in the 70s and 80s just to combat the little pesky seaping leaks that eat up warranty money.
Click to expand...

I've always heard the same thing....wondered if it was true. I bet so.
 
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