8BA studs weeping-iron heads

markdtn

markdtn

Senior Member
I have a freshly rebuilt 8BA (in a 9N tractor). Bone stock with iron heads. I used new studs instead of head bolts because I may want aluminum heads someday. I have heated it fully and let it cool twice now. I have retorqued twice. First time 3 moved. Second time none moved. Yesterday I went to set the timing. After running a few minutes I noticed 5 studs weeping coolant from thread by the nut. I changed the oil, there is no water in it. So I read up on this. It seems that the most common advice is MOROSO ceramic seal, Bars Leak, or Permatex aviation sealer. I detest the idea of using stop leak in a brand new engine that I spent so much effort getting all the gunk out of so to me that is not an option that I want to start with. I used ARP thread sealer on the block side when I assembled it. I do not remember if I used it on the head side (don't think so). So, what should I do next? Pull those 5 and use aviation sealer on the block side? Put ARP sealer on the threads on the head side? Run it and see if it gets better?
 
I'd suggest heading to the local old timey hardware store that carries graphite impregnated cotton string used for packing the upper nut of old faucet stems. Spin a LOT if it around the stud and give it a go.

Lonnie
 
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I didn't see that you said you used thread sealer on the studs when you installed them. I use the Permatex sealer when I insert the bolts and have never had a problem. By the way, I think studs are unnecessary and cause more problems that they solve. I only work on 8BA type engines, so I have no experience with the earlier engines.
 
Aluma seal. Some of the big engine rebuilders put stop leak tablets in the water passages
when the engine is rebuilt to ward off some of these problems.
Bars leak makes the stop leak, it comes about 20 tablets to the card.
The ceramic sealer is killer for a cracked block but over kill for your head studs.
The Aluma seal is about $3.00 for a tube.
 
tubman said:
I didn't see that you said you used thread sealer on the studs when you installed them. I use the Permatex sealer when I insert the bolts and have never had a problem. By the way, I think studs are unnecessary and cause more problems that they solve. I only work on 8BA type engines, so I have no experience with the earlier engines.
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I did use ARP sealer on the block side of the stud. This is an 8BA. Should I take these 5 studs out and reseal them or should I just seal the head side of the stud? You like the Permatex Aviation sealer?
 
markdtn said:
I did use ARP sealer on the block side of the stud. This is an 8BA. Should I take these 5 studs out and reseal them or should I just seal the head side of the stud? You like the Permatex Aviation sealer?
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Hi Mark, pull them out one at a time and seal them up with the Permatex #1 (photo below), we do all our builds using this sealer on all studded builds and have not had a single call/complaint on any water leaks.

A tip, drain all the water out, if you have anti-freeze installed already leave it in a pail and fill the system with fresh water after resealing the studs and run it for as long as possible w/o the anti-freeze. If you have no leaks after some time put it back in. Keep your eye on the weather though??

On occasion we also use the G.M. head bolt sealer (photo below also) when we run out of the Permatex, both have been very successful.

Thanks, Gary in N.Y.

P.S. I would also recommend adding those G.M. "tablets" mentioned in the above post just as a precaution, they go in every new auto delivered from G.M. at the plants. Here's a shot of the sealers we use.
 

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Don't leave antifreeze in an open container for even a minute as pets will drink it and die a painful death.
 
GOSFAST said:
...A tip, drain all the water out, if you have anti-freeze installed already leave it in a pail and fill the system with fresh water after resealing the studs and run it for as long as possible w/o the anti-freeze. If you have no leaks after some time put it back in. Keep your on the weather though??....
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We are at freeze danger nightly. I do have 50-50 antifreeze and distilled water in it now. It is in the garage, but it needs to go to a storage shed-I need the garage back. I can afford a week to wait so I guess I can drain it and do the work, then fill with water for a few days and try to run it nightly until I have to have the garage back.
 
markdtn said:
We are at freeze danger nightly. I do have 50-50 antifreeze and distilled water in it now. It is in the garage, but it needs to go to a storage shed-I need the garage back. I can afford a week to wait so I guess I can drain it and do the work, then fill with water for a few days and try to run it nightly until I have to have the garage back.
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The leaks will definitely stop much faster w/o the anti-freeze in the mix.

Like I stated above, keep a watch on the weather, it's that time of year.

Thanks, Gary in N.Y.

P.S. We recommend using fresh water on all new builds, after things are deemed OK, add the anti-freeze, simple. The oil-based anti-freeze tends to keep the leaks from stopping on their own. With the pending weather you just don't need a cracked block after all the work.
 
I worked for a fleet for a few years and we added bars leak to every new build. Not only for leaks but it also prevents rust and block corrision and lubed the water pumps. Solved a lot of problems........like the others said it is used in one form or the other in most oem applications..
 
Most of these products are advertized that they won't clog up an otherwise clean radiator but they can have a detramental effect on one that has crusties getting built up in there. The stuff can also block the small holes in the head gaskets that control the coolant flow. There is always a risk with a system that has been in service a long time. A system that has had a recent engine overhaul and the radiator was either recored or rodded out should not have a problem.
 
After reading all the replies I am going to try the tablets first. Clean block, new radiator, new pumps, etc. Thanks!
 
Maybe to late but bolts are a better idea with aluminum heads.
If you have to pull the heads in the future, you'll be much happier with bolts.
Martin.
 
If you can easily pull the studs (as it is a new engine), it sure wouldn't hurt to put some more sealer on the bottoms of the leaking studs. I used a white liquid teflon sealer on all my studs that go into water jackets.

I also put a liberal amount of anti-seize on the sides of them (to reduce rust potential and help the heads come off later) - and then a good graphite type moly lube on the fine threads to help the torque accuracy. I use ARP products for the teflon and fine-threaded ends and any good quality anti-seize for the middles.
 
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