Broken head bolt, in the block, with the head on.

[Brad S.]

Ok I tried to reuse my old head bolts and it didn't work out, Ill take my lashes later.
The bottom 1" of head bolt broke off in the block.
I was just starting on the line pattern of the sequence at 100 ft lbs.
Question I had after searching here and elsewhere, has anyone ever use a left hand drill bit with a extension
to get the broken piece out???
And, has or can it been done without taking the head off??? This is the drivers side, BTW.
The threads had been chased with a tap, had put some oil on the bolt threads before installation.
I know that part is torqued in about 99 ft lbs or so.
I think it was bolt #11

 

[franklin2]

If the broken piece is just sitting in there, you could easily get it out with a left hand drill bit. If it broke off because the threads bound up or it bottomed out, and it's stuck in there, then you are not going to be able to get it out easily.

 

[Brad S.]

I don't know if it broke because it bottomed out.
My hope & guess it was over stressed or too old etc. Since I cleaned all the holes, thats why I'm hoping.
Thanks

 

[metalminded]

Good luck man.... this is what we all fear.

 

[idiabuse]

Got a picture of the broke bolt? that would help...


Javier

 

[Brad S.]

Got a picture of the broke bolt? that would help...


Javier

I'm gonna post one tonite, when I get back home.

 

[icanfixall]

Well that sucks but let me ask some questions. you posted the threads were tapped out.. But did you use a bottoming tap or statring tap. It makes a big differance which one was used. As for knowing why it broke is nearly impossible at this time. If it bottomed out then your really in a pickle. If it broke because it was "ready too or damaged" then you are ok. A left hand twiat drill bit will get it to turn out but. The block is counter drilled about 1 inch down meaning there are no threads at the first 1 inch of the bolt bore in the block. Plus you have another nearly 5 inches of head to try to pull out the broken piece. When I broke two studs from DPS I pulled the engine. Removed the head and still had trouble getting the stud out. They were H13 material. Thats 270,000 psi material and very hard to cut into. I ended up using a small Dremel tool and a 1/16th burr to cut a slot for a straight blade screwdriver to back out the broken stud. As I was grinding the slot the broken stud strated to back out because of the grinding vibrations.. I was a lucky dog that day. Then I used a magnet on a flexiable shaft to pull out the broken piece because there are no threads to continue to thread it out. As I posted. This was done with the head off the engine and the engine out of the truck. I'm thinking your trying to do this with the engine in the truck. Have you torqued down one head yet. If one bolt was suspect what are the rest of them looking like. Can you see any corrosion on the broken bolt shaft.

 

[Brad S.]

Well that sucks but let me ask some questions. you posted the threads were tapped out.. But did you use a bottoming tap or statring tap.

Don't know the difference, the tap I use has flat end on the cutting or bottom end.


When I cleaned the holes I ran the tap down, cleaned off the tap after each hole, then I turned a head bolt in just to see how the threads "felt".
I sprayed each hole with some PB blaster before I started the process, if there was too much left in the hole after I ran the bolt in
would excess fluid cause it to "hydrolock"
Running the head bolt in after the tap, would push out alot of the fluid, I figured that would clean out the hole enough.

 

[idiabuse]

Really, how can you bottom out a bolt with the head on? I cant remember if they are all the same length? I think they are.


Javier

 

[Brad S.]

I think if there was enough crud in the bottom of the hole, then maybe.
Not sure just guessing, never had this problem before.

 

[icanfixall]

Your answer about hydrolocking the bolt because of oil or fluid stil in the hole can and will happen. You needed to blow out all the chips and fluid before a bolt was installed. Sorry to tell you this. Now please understand. All the head bolts are the same length too. Also not knowing if you actually used a bottoming tap is not the best of news either. Look at the tap again. It will tel you just by looking at it or by the nominclature printed on the side of it. Normally a bottoming tap wil only have one or two threads cut down on the bottom of it. Every tap comes in three differant names. Plug bottoming and starting.

 

[jaluhn83]

The next thing I'd be worried about is if any of the other bolts have the same problem but didn't *quite* break - that is, they're not completely tightened or stressed or whatever enough to cause potential failure down the road.

My recommendation would be to pull the head(s) back fully off, assess the damage/source of the problem and go from there. Expensive in time and money in the short run, but could save quite a lot of both down the road.

 

[Oog]

Son, I would pull the head(s) and replace, retap the bolt holes again. A bottomming tap looks like a bolt - squared off towards the tip, not pointy like a nail.

As for the one bolt that broke: beg, borrow or steal enough money to buy all new bolts. It's better to buy them now than in a week.

 

[Brad S.]

Well got a pic of the bolt just cant get it to load right now, and I do have a new set of bolts coming.

 

[riotwarrior]

IMHO the best...method

Pull engine,

Pull head

Get MAGNETIC base drill..maybe rent one

get four flute milling bit and LH drill bit

FOUR FLUTE milling bit about same diameter as head bolt shank or just under that...

Slowly run that flute bit down and get it centered and LOCK the mag drill...then mill off the top of broken bolt

Next with a FLAT broken bolt in hole, the KEY is its FLAT you can now take your LH drill bit and run it down the hole and begin to work out that bolt by drilling dead centre.

If you have to you can use an easy out however it could invariably break to.

Good luck...

JM2CW and thought likely the most time consuming and complex is the least likely to cause a problem

Option 2

Take it to a machine shop and have them do it!

Al