How to remove a Broken Bolt
 

How to remove a Broken Bolt

There are many different methods.

This is one of the more common methods using an EZ-Out


This method works best on bolts that broke due to being over tighten.
The EZ-out method has little success on cross threaded or rusted bolts.

The tools needed are few.
https://www.miataturbo.net/attachmen...ine=1357313066

Drill
Proper size drill bit
A good sharp center punch
Hammer
Crescent wrench
Proper size EZ-OUT

There is two different styles of EZ-out, A left handed spiral flute and a straight flute.

I will be using a spiral flute in this removal.
The spiral flute will screw down and get a firm “bite” on the inside of the broken bolt.
First with the hammer and center punch, knock a good divit as close as possible to the center of the bolt.
https://www.miataturbo.net/attachmen...ine=1357313066
This is done so the drill bit will not walk around when you start to drill.
https://www.miataturbo.net/attachmen...ine=1357313066
Now with the drill bit in the drill motor.
I am using a 1/8 inch drill bit, the broken bolt is a 8mm (5/16ths)
https://www.miataturbo.net/attachmen...ine=1357313066

Drill appox. 1/8th to 1/4th inch down the center of the bolt.
Drill as straight as possible.
Some times it will be necessary to drill all the way through the bolt.
https://www.miataturbo.net/attachmen...ine=1357313066
Blow all the metal chips out of the bolt hole.
https://www.miataturbo.net/attachmen...ine=1357313066
Now take the EZ-Out and tap in to the hole you just drilled.
https://www.miataturbo.net/attachmen...ine=1357313066
Now using the square on the back end of the EZ-out.
Gently apply pressure to the broken bolt, until you feel movement.
If you apply too much pressure, and snap the EZ-Out off in the hole, you will have more serious issues.
https://www.miataturbo.net/attachmen...ine=1357313066

Do you have a method for rusted bolts? Thats my big issue, thanks New England. I've broken off many an ez out (straight and spiral) trying to extract rusted bolts.

for rusty stuff, i just do the above + fire.

i live in England, so my car is about 94% rust.

This is about the only thing I have ever managed to accomplish with an EZ-OUT.

The EZ method seldom works on a rusted bolt, it works best on a sheared, or streached bolt.

I am working on another method to show you for rusted bolts.

^^ This, alot of fire, make it glow!

Most the time that is becuse the hole is not large enough, I commonly see this with people that have not used ez-outs alot.

I've never had much success with ez-outs either.

I tend to go straight for the red wrench (heat) for any stubborn or rusty bolt or nut...

I have had the EZ method work well in the past but I use PB blaster + time and then if it still does not work then get out the torch.

PB Blaster or Kroil + smokewrench = winning

Don't you homos ever reassemble anything with copper anti-seize? Loctite 37616 stick FTMFW

https://encrypted-tbn2.gstatic.com/i...jLqhwAT6Fw-Wow

I live in the rust belt. Everything gets the standard grey never-seez. I've been using it for decades. I'd sooner give up my ratchets than that stuff.

Tell that to the former owners of my car. I'm just fixing their mistakes. :vash:

I joined the "only thing I've managed to do with an EZ out is break it" club this weekend. First and probably last time using one.

Gotcha, I'm a member as well. I just paid great heap wampum to have 8 broken bolts removed from the heads on my truck. :vash:

How much they charge you per bolt???
The heads off?

Apparently 1/8th of a heap.

My last EZ out attempt actually worked!! Joe, remember that AC bracket bolt that causes an oil weap when it's missing (or, in my case, broken)? I actually removed it easily with an EZ out. I was shocked. Must be living right.

I think the key with an EZ out is that it doesn't hurt to try but don't apply significant torque. It either starts backing out pretty effortlessly or you should be trying another method.

It has been my experience that the spiral one breaks a whole lot easier then the square ones. I have broken a few spiral ones over the years but have never broken a square one, it usally just lets go and starts reaming out the hole. It doesn't screw itself in like a spiral one does and I don't think it is heat treat hardened as much as a spiral one.

edm drill

You have no idea how badly I would love to plop down the couple grand that one of these babys cost. Just a simple tap disintegrator with a magnet base would be all sorts of winning. I never looked heavily but if they made a magnet base model small enough to fit in an engine bay with the engine in it, it would be amazing.

Heads off, and A LOT. I literally could have bought a running NA for what I paid, but it wasn't just the bolts. I managed to break off 4 of the 8 exhaust manifold bolts in each head while trying to R&R the broken iron manifolds. I broke 2 EZ-Outs before throwing my hands up and then ripping off the heads and the 9,000lb iron intake manifold and paying someone to fix it. I took the opportunity to have the heads completely rebuilt and also install some headers. Runs better and get more mileage now that all the valves seal ("more" is a relative term with a Ford FE.) Funny how that works...

I honestly didn't look, the total was hideous. I didn't WANT to know after 16 new valves, seats, seals, machine time and shop hours to get it all put together. The shop does GREAT work, but yee gods, they are expensive. I'd not hesitate to trust them with anything... if money was no object. Needless to say, I will think twice and explore many options before using them again.

Hah. I did exactly the same thing on my Fury (MOPAR RB Block instead of a Ford FE). Heads needed rebuilding anyway. Took the opportunity to get hardened exhaust valve seats put in for unleaded.

Heh - thanks for the writeup/comments. I get to start my very first ez-out adventure with this guy. Bolt that holds down the battery bracket in the trunk snapped clean off at the threads.

https://www.miataturbo.net/attachmen...ine=1357448975

True, always feel for slight movement, and try not to superman the broken bolt out on the first try.

Also how the hole is drilled can make or brake an ez out removal.

Oh a FE Ford!! How I love/hate those heads!

I am going to guess about a grand for what you had done. I have done bunches of those heads, they are never cheap to fix right.

What casting number are they?


From the looks of that break, an EZ out should work.
Once the hole is drilled, about 1/3 the bolt dia.
Then taper the hole some at the top so the ez out will get a better bite.
Some penatraint oil once the hole is drilled all the way through the bolt will help

I've removed more than my fair share of broken bolts in my life (2A7X1). A few things that make easy outs easier to use and more likely to work:

Get a small ball burr https://www.miataturbo.net/attachmen...ine=1357504047
And round the top of the bolt. This makes it much easier to drill the bolt on center and reduces the chances of breaking a drill bit if the top of the bolt broke off in a jagged manner.

Use a tap handle instead of an adjustable wrench to turn the easy out.
https://www.miataturbo.net/attachmen...ine=1357504047
This allows for a more even pressure so the easy out is less likely to cock( :p ) over to one side and spin.

If the broken bolt is large enough that you can get a decent size easy out in it, while you are turning the easy out tap the end of it with the hammer. This helps seat it and makes it less likely to spin in the bolt. WARNING: this is generally the step at which I have broken most easy outs.

If the bolt really isn't coming out at this point, before you break an easy out in the hole, look to see how close to centered(and straight) you were when you drilled the bolt. If you did a good job, you might consider using one size smaller than the tap drill bit for the bolt and drilling the whole thing out. Once you do that the proper size tap should be relatively easy to run down the hole.

If you do break an easy out in the hole, take a center punch and a hammer and beat the ever living shit out of the easy out. They are very hard and thus also rather brittle and if you get lucky, the easy out may break enough that you can get the pieces out with a scribe. If it doesn't shatter, well you were fucked anyways right? Get out the carbide burr in the dental file and prepare to be at it a while. Or take it to a professional who will charge you a "grip" of money extra for making his job harder by filling your stuck bolt with a really hard steel core.

Exactly the same thing on my car.

I can"t believe how that battery bolt snapped off!

D2TE. I briefly considered putting Cobra Jet sized valves in it, but then I realized "this is a rusty ass truck, stop spending money" and went with stock size replacements. It never ceases to amaze me how ENORMOUS the ports are on these heads. EBay supplied me with an ugly and well loved Performer RPM intake and I found an Autolite 4100 at a swap meet for $20. I ditched the "emissions compliant" points distributor for a recurved Duraspark and an MSD box. It now pulls like a goddamn freight train and probably gets 9-10mpg... up from 5-6mpg.

For those of you unfamiliar with 60s tech big cube domestics, here is an intake valve:
https://www.miataturbo.net/attachmen...1&d=1357522551
Puny George Washington is no match for my stock intake valve! It's literally slightly larger than the top of a RedBull can

You people keep driving your hybrids DDs, I'm gonna need the fuel.

$.02 on stuck bolts:

1. Kroil kicks ass on BP Blaster - not even close. Soak, reapply and be patient.
2. If possible, use a box wrench and tap it with a rubber BFH. Constant torque yields that horrible waxy feeling of a bolt twisting in half. Taps with the hammer (after Kroil soak) yields that beautiful 'POP' of a fastener breaking loose.
3. When 1 and 2 fail, you sometimes get lucky with a reverse thread drillbit. You need to drill a hole anyway and the reverse is at least pushing the metal in the direction you wish it would go. I've had a few come out this way but as BogusSVO said, they don't really work on rust.

Kroil is magic. I have a set of dikes that fell out of my workbelt several years ago doing a project on the side of the house. They got buried in the grass and when I found them ~3 years later, they were a ball of rust. I couldn't pull them open with all of my strength. I soaked with Kroil and an hour later I was able to pull them open - barely. More kroil. The next day I could open and close them fairly rapidly but with resistance. I hit the exterior with a wire brush and added more kroil. A week later I could open them with two fingers. More kroil. A week after that, they would fall open under their own weight. Still in the tool box today - still my favorite set of dikes. True story... :party:

Kroil also smells better than PB and gets bonus points because it works on firearms as well.

I use Kroil a LOT at work with airplanes. it is a life saver. Also when kroil evaporates it leaves a little lube rather than drying up like WD-40 does.

Too many people assume because it gets rid of squeaks that WD-40 is a lubricant. That couldn't be further from the truth.

For all things rusty:

If you have air, I find air hammer works like a charm almost all the time. Just hit the nut/bolt a few times with some penetrant and you're good to go.

Another trick I've been taught if you have a good impact is to shoot it CW first a bit then back out.

For any bolts/nuts I'm concerned with shearing off or don't look so great to start with, I'll usually try to fit a wrench vs a socket and then just use a hammer against the wrench to break it loose initially.