Broken/Snapped Head Bolts In White Block

Post by **asg1986** » 21 Dec 2012, 09:43

HELP!!!

I broke off 3, yes 3!, headbolts while taking the cylinder head off my '96 960's engine. (I know this is the wrong forum, but basically the same engine). The bolts broke off about 2 inches below the deck, and have between 1 1/2" and 2" of bolt left. They've been soaking in PB Blaster for a week, and I've been looking for ideas online, but I still feel unsure. I was going to try drilling them out with left handed drill bits, but I don't know that I have the variety of sizes and the length needed to do this job. I have never had any luck with easy outs/ bolt extractors. Anyone have any ideas? These broken bolt pieces that did come out had charred ends - almost like a layer of charcoal on them...

Post by **JDS60R** » 21 Dec 2012, 10:43

You can use Chemtool b-12 to melt carbon but it rarely gets in there. Its possible the thread lubricant used was substandard and dried out over the years. I would suggest either TIG welding a bolt or rod back onto the broken bolt so you can try extracting them after a good soak in 50/50 acetone and transmission fluid.

If you have no access to a welder drill the bolts 90 % through and then tap them,left handed and remove.

If you can identify the bolt material I can suggest an acid that will dissolve it.

Post by **cn90** » 21 Dec 2012, 10:49

1+,

Post by **asg1986** » 21 Dec 2012, 13:07

JDS60R wrote:You can use Chemtool b-12 to melt carbon but it rarely gets in there. Its possible the thread lubricant used was substandard and dried out over the years. I would suggest either TIG welding a bolt or rod back onto the broken bolt so you can try extracting them after a good soak in 50/50 acetone and transmission fluid.

If you have no access to a welder drill the bolts 90 % through and then tap them,left handed and remove.

If you can identify the bolt material I can suggest an acid that will dissolve it.

Hmm.... I like the idea of dissolving the bolts

I have no experience with welding (yet, but I am taking an automotive welding class next semester). Is the Chemtool b-12 available at most auto parts stores? Is it safe for the aluminum block (I have the head off, btw). I don't know the metallic make-up, but according to partsgeek.com the OEM supplier for Volvo 960 head bolts is Victor Reinz.

Post by **wheelsup** » 21 Dec 2012, 20:35

I recently had to drill out some screws from a 70+ year old bench vise. I picked up the reverse drill bits @ Harbor Freight. Worked like a charm. If the simple drilling of the bolt doesn't unwind it, you can pound an easy out, either the spline one or flute (flutes are generally longer) and take it out. This guy used an adjustable wrench, probably better to use some sort of sliding t-handle on an 8-point socket to get it out, that way even pressure is applied.

Post by **JDS60R** » 21 Dec 2012, 21:02

I would soak it first in trans fluid and acetone and then see if you can get it started turning with a punch and a hammer.

If not, and its a ferrous metal stuck in an alloy section of the block, you can dissolve it with heated water and potash of ALUM . This is best used for a part you can soak/submerge in a heated container so you may have to use an industrial activated blended version.

You may have to use tap-X. If you don't know how to use acids safely please leave it to an expert. You will need to test the broken bolt before using this in the block. I do not have the metallurgy on the bolt so I am not sure it will work. Make sure to tape off and fully protect the cylinder liners and other ferrous components the bubbling acid may contact. If you are an inch below the surface you should be fine. The clay does not work at all. If you need to build a dam use RTV silicone and let it dry before starting. When done make sure to deactivate your acid and flush with tons of water and blow clean with compressed air. You must start with degreasing the hole.

Please be careful,
John
http://www.westtool.com/default.aspx?pa ... %20Results

Post by **asg1986** » 30 Dec 2012, 14:52

Well Guys: still no luck. So far I have purchased left-hand drill bits from Harbor Freight. I drilled into one of the broken off bolts, and I wasn't quite centered. So I tried to make a guide out of a #16 bolt that I grinded down (so it would fit), and then I drilled through it. I made a few of these guides because I was having trouble getting a perfectly centered hole, so I haven't used it on the block bolts...

Then I tried acetone and transmission fluid. I let it soak in overnight, then tried to get a punch down the hole, but it is too small to really get a good angle to hammer.

I did order some Tap-X, but its taking a while to reach me due to the holiday season. While discussing my predicament with my cousin he asked if the head bolts are threaded into aluminum or if there are steel sleeves cast into the block for the head bolts? I thought this would be a good question to toss out there before I drop acid into the hole

Post by **JDS60R** » 30 Dec 2012, 15:30

Use a magnetic pick up tool down the threads of one that did not break and check for ferrous thread inserts.

Post by **vjaneczko** » 30 Dec 2012, 15:37

I know the panic you feel; I had the same problem. I got a left-hand bit and let a ton of PB Blaster soak in the tube overnight. Came out like butter. Keep your fingers crossed and go for it.

Dempsy · Post by **Dempsy** » 30 Dec 2012, 17:26

I hate to say this but a tow truck and a machine shop may be in your future. I feel for you man...