Head Bolt continually weeping

G

guy1unico

Well-known member
Painted the heads, installed stainless bolts, torqued bolts to 60 and a few will not stop weeping. Any suggestions of how I may stop these annoying leaks?
 

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Put some thread sealer, I like Loctite PST, on the fine threads, re-install the head nuts and retorque.
 
Don't seem like much of a leak. If it were mine, I'd leave it alone. I agree with Lawson. It might eventually stop all by itself. Jack E/NJ
 
I had that problem on a rebuild that sat on my run stand. Had coolant in the system that would weep between the stud and the nut. Continued weeping for many months. Got tired of it and blasted it with compressed air and immediately put super glue on it and let it wick into the threads. Never leaked again.
 
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leak is really coming from the threads on the stud, one a new stud installation I use permatex #2 non hardening on the studs. only way to seal the studs is from the water jacket side. on a problem like this I use the old style pellet stop leak from barrs, put it in run the engine until hot and then stop the engine and drain out all the coolant and barrs leak. save it for now, leave over night then fill up with water and run engine. I have had to run the solution thru a couple of times to make them stop. then drain and refill with your antifreeze
 
When applying the silicone on the head bolt do I need to drain all antifreeze...you cant just silicone and put back into the greasy antifreeze filled whole or can you?
 
guy1unico>>>When applying the silicone on the head bolt do I need to drain all antifreeze.>>>


Sorry, you can't apply anything to the head bolts in your situation. Jack E/NJ
 
guy1unico said:
When applying the silicone on the head bolt do I need to drain all antifreeze...you cant just silicone and put back into the greasy antifreeze filled whole or can you?
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Maybe it is just terminology, but you keep saying bolts but the photo you posted shows studs with nuts. The only options you have without pulling the studs is a sealer in the coolant. Increasing the torque on the nuts does nothing at all as far as sealing the leaks goes. It is leaking through the threads on the studs in the block. You can pull the studs and seal them better or use a sealant.
 
JSeery said:
Maybe it is just terminology, but you keep saying bolts but the photo you posted shows studs with nuts. The only options you have without pulling the studs is a sealer in the coolant. Increasing the torque on the nuts does nothing at all as far as sealing the leaks goes. It is leaking through the threads on the studs in the block. You can pull the studs and seal them better or use a sealant.
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MUCH easier said than done, in most cases.
 
It most likely will stop weeping on its own, but you can put a little bars leak powder in the radiator if it bothers you.
 
Seems it may be a fresh engine, shouldn’t be tough to remove the studs. Are those studs SS? The nuts look like they are, but the studs have a dull iron look to them?
 
First there are many on here more "versed" than me BUT the first "Red Flag" I read is the use of Stainless Steel Nuts........At 60ft/Lbs you are about 24Ft/lbs more than the "generally" accepted torque value for Stainless Steel. I have some SS cap nuts and were advised NOT to use those as a quoted "maximum" torque recommendation was 40ft/Lbs.....I myself would not use ANY Stainless Steel fastener for something critical like head studs and nuts!!!!! JMO


Based on what has been posted, did you heat cycle the heads and arrive at 60???? IF you haven't heat cycled and re checked your torque then you could have one that stretched and now is not at 60Ft/Lbs


can of worms now open
 
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rockfla is 100% correct about not using stainless nuts and bolts as they shear too easily using the torque required on head bolts. The threads will stretch, especially after repeated use.
 
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