Originally Posted by eric32
Hello guys I have somewhat a minor issue or maybe will turn into something big but either way I have some head studs seeping out some antifreeze on my passenger side of my small block chevy and the driver side seems to be ok as I wiped the stud ends and they were all dry but I have one stud that you can see the antifreeze laying underneath the stud nut itself but does not gush out or anything and maybe a few others that are seeping but don't seem to be as bad.
This engine was taken out of my truck earlier this year and I put a set of aluminum heads on it and I don't know what was used on the studs but my father was the one who put it together as I was recovering still from cancer treatments at the time. The block was completely cleaned and all threads were chased and checked before the studs were put in and I am guessing he used Teflon tape to put on the threads on the studs.
We used Teflon sealer paste before but the studs leaked everywhere and he never liked to use that stuff for head bolts or head studs but that is what I got but it did not seal hardly at all so had to pull the whole motor out take off heads and reclean everything and used Teflon tape as its been used for years with no issue on his many builds he has done and even put indian head on the bolts as well just to keep things sealed and it worked like a charm just fine.
Have since changed heads like I said and from what I have read sometimes its a hit or miss with the arp studs leaking regardless of what way you seal them with Teflon tape Teflon paste or permatex no 2 etc. My Father I know would not have time to pull this thing out and its been apart so many times cause of this issue or that issue cause of dumb luck with stuff I hate to have to pull it out for like the 6th time in 5 years just for like 4 seeping studs.
The other ones are back at the number 8 cylinder and would be very hard to get too. So my question is any suggestions on what I could do? Some of my studs have to be double nutted to get them out as the allen part stripped out. Can I use a bottle of bars leak engline sealant and is it safe to use?
As far as trying to take the one stud out then try to seal it up again that would be a task and a half as I know the threads have to be squeaky clean and with out really tearing the motor down there is really no way to be able to do that from what I can think of.
Studs are more difficult to seal up than bolts. My preference for bolts is Teflon plumber’s pipe sealer but it like any other sealer on bolts really needs to be applied to the female thread in the block as well as the bolt simply because the act of inserting the bolt wants to push the sealer up the threads which exposes the bare end to the coolant. By applying sealant to the female threads all the way to their base in the cooling jacket then as the bolt is inserted it pushes a bead of sealer ahead of its end keeping it from becoming bare of sealer. This greatly helps in keeping the lower threads coolant tight. The two other advantages of Teflon pipe sealer are that the stuff doesn't harden so that whatever amounts fall into the cooling passages are disintegrated into a solution with the coolant by the pump so that there are no hard particles to plug up small passages and the stuff has about the same lubricity as engine oil which the OEMs use a torque guidance so you end up with the same amount of stretch in the fastener for the specified torque. I use this technique for all forms of fastener sealants.
That's bolts, studs are different because you not only want to seal their threads in the block but you don't want them turning with the nut as you pull torque because stud sealers tend to be RTV, Permatex #2, or epoxy. These are things that do not flow to refill gaps that form if the stud turns with the nut. There is no way to absolutely guaranty that the stud won't turn enough to break the thread seal as usually the head is not promptly installed so the sealer will have time to cure before torque is applied so any movement of the stud greater than the elasticity of the sealer to move with will open a route through the sealer for coolant. My method of sealer application for studs is the same as bolts in that it goes on the female threads as well so there remains a reservoir of sealer to fill the threads as the stud is screwed in. If I use epoxy I pull torque as soon as the stud is at the proper installation length by using a silicon grease coated washer on the bottom at the head deck, a length of pipe for the stud body then a top washer and the nut. Then holding the stud from turning with an Allen in its end, I pull it to torque with a crowfoot wrench. This latter technique of using an Allen wrench to keep the stud from turning while torquing is also used when the head is set down even with pliable sealants to keep the stud from turning. You will find it necessary to purchase a set of offset sockets to do this, example <<< S9723, Socket, Spark Plug, Offset, 5/8", 12-point
I would not recommend using studs unless this is a competition engine that needs to accommodate teardowns in the pits, or suffers some other predominate need like for high blower pressures, or aluminum blocks simply because these studs demand better assembly techniques than bolts so if they aren't needed for some extraordinary condition I don't use them. Keep in mind that studs epoxyed into the block not come out with the Allen wrench. These are sacrificial studs as you’ll most likely have to unscrew them with Vise-Grips.