ARP bolts leaking on the heads

[MONTE]

I just finished my engine but I noticed a problem.
The bolts on the aluminum heads are leaking. My builder told me that its a common thing and not to be alarmed. He told me to give a few runs and that it should stop. He also told me that if it dont stop he can put some type of sealer in the radiator and that should take care of it. Is this true or is he just blowing smoke? Ive invested lots of money into it so I want it to be right. Its not a lot of water but I can see the drops coming out.

[COBRO]

No he isnt blowing smoke but its a stupid statement comming from a builder - any head bolt regardless of the make that goes into the water jacket should have sealant on it when its installed or its going to leak period! Yes a sealer dumped into the cooling system may stop the leaks but what else is it going to plug up while its doing that??????
Iffn it were me I would pull the bolts and apply a sealer along with new head gaskets.
HTH CB

[shortbed70]

I'm assuming it's the bottom bolt or exposed bolts that are leaking. I have seen a many leak on new heads justpull them one by one and seal them then reinstall and re-torque all bolts.
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[MONTE]

Thanks. I need to look into this and make sure its done right.

[Marv D]

If the lower bolts are leaking,, ummmmm you better pop a valve cover and see if the others are too.

I've put motors together with studs and no matter what type of sealer I used on the studs, they stupid things weeped. A bottle of bars leak 'will' cure it, but it's something you just have to use as a last resort.

For bolts, the block needs to be DRY for any sealer to really work well, but a smear of permetex HiTack on the threads will usually seal the head bolts that go into water and not effect torque.

[Wild83C10]

I've never had or seen head bolts leak. The first time I used studs they weeped. The sealer did work eventually on the studs.
If your bolts are leaking I would be a bit worried that they weren't sealed properly to begin with.

Marv, Have you ever tried the Permatex Indian Shelac on studs? I've heard that is the one thing that actually works on studs.

[68 C-10 KID]

I second the head bolt leakage. A good sealer that the bolt company recommends so it doesn't change the TQ value.
I started to put a sealant in the water systems in all my new motor builds. On the 1st fill up and heat cycle. It help seal op the freeze plugs also.
Also having aluminum heads with a hi compression ratio will make the heads move around a little. So I recommend a re TQ.

[Marv D]

Originally Posted by Wild83C10

Marv, Have you ever tried the Permatex Indian Head Shelac on studs? I've heard that is the one thing that actually works on studs.

Nope, sure havent used the shellac in many many decades. In fact the last motor with studs into water we used permetex green (sleeve retainer) to get the dam things to dry up. Bolts I use a smear of Permetex Hi-Tack and have never had a problem,, with bolts that is. Gotta makeyou love the Dart and Motown blocks with blind tapped holes that don't go through to water!!! :-)


Heard just last night a buddy using the indian shellac. Kind of surprised me as I said,, haven't heard of it in many many moons. But it worked back then for a heck of a lot more than threads. Ought to do the trick!

[GMR-PERFORMANCE]

I have found that even with sealer you can get a leak, blind holes in the blocks solve this issue however make sure there is no coolant that drops int he holes when you take it apart. and blow them out 100% before you put it back together ..ask me how I know .

I like the ceramic sealer works great and there is no issue using it... GM has add stop leak to all of there new vehicles for many years now.

[MONTE]

Thanks for all the info guys. I will work on it.

[gchemist]

I used this stuff on my aluminum intake. It works great!!

[onequickchevy]

I use the shellac. My dad taught me how to build an engine, and thats what he used, so I do to. He raced AA/FA in St. Pete in the early 60's with Buick Nailheads. Good enough for pops, good enough for me. My heads are aluminum and I have had zero leaking around the head bolts.