Silicone(?) used to repair leaking head bolt

jscap99 · 08-11-2008, 02:01 PM

Looking for an old post, someone had repaired a leaking head bolt with silicone. I need to know the info on this. What kind (product) silicone? Is it the stuff in caulk guns? I have some gasket cement I might use. Any and all info would help. Thanks, John

dobber · 08-11-2008, 02:16 PM

You could try the stuff in a brown bottle that they used on the heads of old Ford motors, I think it was a Shalk type of product. Not sure what it is called.

jscap99 · 08-11-2008, 05:55 PM

Are you talking about gasket cement. I have something like that, it's a small brown bottle, and theres an applicater built into the cap. but it's really strong stuff, and thick. I'm a little afraid to use it. -John

dobber · 08-11-2008, 07:00 PM

Ya, that is the stuff. It smells like bad varnish, and if you do use it, it is some tuogh stuff to remove later. Question from you though, do you have a loss of compression through a head bolt? If that is the case, do you have a bad head gasket or a warped head?

jscap99 · 08-14-2008, 12:54 PM

It's a new head gasket. The engine is running like theres an air leak when it reaches temperature. Theres oil bubbling around a bolt where the head gasket is, on the drive side of engine. I might seal it up with this strong stuff since I have no intensions of rebuilding it. I would seal it just in the area that appears to have the problem. I also need to check the intake gasket. I replaced it on this engine before. any ideas? -John

dobber · 08-14-2008, 11:51 PM

Does it have a cracked block from the valve to a head bolt? or maybe somebody put a to long of a bolt in one of the holes and cracked the block?

Do you have a lack of power? I had one that ran like crap from a bad Intake Gasket.

Also how many pounds of compression?

jesse8931 · 08-17-2008, 12:04 AM

if the bolt is tight is the oil on top of the piston?

**rudedog** · 08-17-2008, 01:23 AM

What are you working on?? Sometimes headbolts have a shoulder on them, and have to installed in a certain hole. Dobber nailed it, some of those old Fords had exactly that type of bolt, but they would leak coolant, because the bolt actually went through the water jacket in the head. Also because of that, the shoulder would corrode due to lack of maintenance and electrolysis, and the "easy fix" was to slather them all up with silicone.

bugman53 · 08-17-2008, 04:07 AM

I would check for a warped head and put another new gasket on it.

But for your question. You can use a liquid high temp thread sealer used in steam pipes made by loctite. I forget the # of the product though. works like a charm. and it will come back out pretty easy.

**Strigoi** · 08-18-2008, 12:56 AM

my buddy and i "fixed" a leaking head gasket (was leaking out of a head bolt) on a 3.5 tec with some silicone. we just siliconed the bolt and put it back in.