Broken Head Bolt Extraction

[PDX2012]

Just wanted to share a possible solution for anyone with a broken head bolt.
My mechanic wanted to pull the engine, (or scrap the car) after breaking one of my head bolts aprox. 2 inches below the head.
I went down to his shop, took measurements & machined a tool for deep extraction.
10 minutes of drilling with a left hand 19/64 cobalt hardened bit and it was out.
I hope this helps anyone out there avoid extra cost or engine replacement.

IMG_4370.JPG (190.73 KiB) Viewed 2373 times

[Ozark Lee]

Welcome to MVS,

That is pure genius. Now, where did I put my metal lathe?

Did the bit just bite on the broken part of the bolt and pull it out or did you still need to use an EZ out?

...Lee

[precopster]

A left hand drill bites in by drilling anti clockwise; perfect for thread removal. Haven't seen too many of these at the harware shop!!

[PDX2012]

Well I drilled into the bolt about 7/16 or so - around 5 tries - and the bit did the work.
To be fair; part of an EZ out was used, but it was turned by hand.
A piece of gum & a stick most likely would have taken the bolt out all the way.
Note: Hole was filled with WD-40 the night before.


John

[rqcook]

Hey,

Looks like you did a great job.

I also am into a new project - one that was left with
me 5 years ago. Looks like I might need to drive
it - as the daughter blew her Santa Fe.

Is the guide you made -
available to loan/rent/ or sell?

Or did you perhaps make 2 ?

Looks like I need something like that -
and don't really have machine shop to use.

If you monitor this thread -
call me -

Rowan 304 581-4051
What ever help you might offer.
thanks.

[rqcook]

I'm taking a moment to share what else might help those people
who have a broken head bolt in the 2.9 Volvo engine.
Or any of the other wet sleeve kind of Volvo engines that might
have this issue.

I saw the post above that started this thread ...
And

I had a single bolt out of all the head bolts break off.
--------------------------------------------------------------------.

This motor block is an alloy block -
Nearly every bolt there -
had galvonic bonding created that had created an electric
weld of ions of the dissimilar metals to one another.

The engine was not assembled - in an over tightened
condition originally.

This came about with time, use and current flow through
the antifreeze, block and hardened steel bolts.
____________________________________________________.

Nearly every bolt coming out gave me a fit.
I nearly broke the 18" ratchet bar - on every bolt.

Only 1 bolt body stayed frozen in the alloy block.




I sized a 1/4 drive hardened torx socket to go down into
the bolt hole.

I had to drill the center of it out to be the size of 3/16"
The 1/4" socket served to help keep the drill bit centered
into the center of the bolt body.

I did not have access to the nice centering guide that was pictured
in the post up above.

I used a chisel close to the size of the bolt body to put
2 hatches across the broken end of the bolt so that there
was a cross on the head of the bolt.

This gave me a center point to begin drilling.

I did use a 3/16" left handed drill bit.
And using a battery pack drill drilled deeply into
the center of the bolt.

Using PB blaster, Patience, and air nozzle to keep the metal
shavings coming on out ... I was able to go nearly 2" down into
the broken bolt body.

All the while ... I took a larger center punch and tapped on to
the head ... when I felt no give as I was drilling.

When I realized that I was quite deep into the broken bolt
I stopped drilling.

I went to my extended length male torx bits and found one the
size closest to 3/16" - and drove it into the hole that I had just made.

A 1/4" ratchet was used for the drive handle - to attempt to tighten and
then loosen.

And - it was still galvonic bonded.


Electric current created the bond.

So - I used electric current to break the bond.

Using a shop battery charger on 10 amp -
I applied current to the torx bit driven into the broken bolt
and
attached the other end to the mounting bracket on the starter support.

Current was not on the unit 30 seconds ...
Turned the charger off.

Applied a little tightening force - and the bolt released.
Move PB blaster,
Rock the bolt back and forth a little,
Then a little more.
Then a lot.

All time involved - almost an hour.
More time getting prepared to do it that getting it done.
___________________________________________________.

Had I treated it some other way ...
Likely I would have had to scrap the block & get a salvage yard engine.

This way,
I can go forward with servicing the head, t/belt, tnsrr & rollers.


And I hope that this might help someone else as well.


The key to it all is - to keep the drill bit you are using centered
in the thread core. The small short 1/4 socket did the trick.

You can do it to.

Rowan Cook
Raleigh County, Beckley, WV

[Faust]

Just wanted to share a possible solution for anyone with a broken head bolt.
My mechanic wanted to pull the engine, (or scrap the car) after breaking one of my head bolts aprox. 2 inches below the head.
I went down to his shop, took measurements & machined a tool for deep extraction.
10 minutes of drilling with a left hand 19/64 cobalt hardened bit and it was out.
I hope this helps anyone out there avoid extra cost or engine replacement.

I knew that if I held on to that knurling tool long enough, I would find a reason to use it.