How to remove broken caliper bracket bolt?

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Quick update here, I received my reverse easy outs drillbits etc. and attempted to remove a stuck rotor screw to get the feel of it, and well no dice. The easy off broke within seconds inside of the drilled out rotor screw 😩 that I spent another hour trying to drill that out and finally gave up put everything back in the box cleaned up and called it a day.
B8CDDB70-12EE-455C-839D-434B3304E086.jpeg

Drill carefully, hammer in extractor, turn with a tap socket.
 
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The car at this current point is completely drivable and everything is tight, including the rear caliper bracket bolt that’s broken, I just can’t remove it myself.
Just because there is a piece of that fastener still threaded in doesn't make it "tight". These fasteners clamp the parts together and without the head on that fastener, nothing is getting clamped.

Caliper bracket fasteners are pretty "big", at least when it comes to those used on a car, and have a pretty high torque setting (much more so on the fronts than the rears, admittedly) because there's quite a bit of torque/twisting force on them when the brakes are applied. I'd be very, very cautious driving this to your shop. I hope it's close and even then, drive slow and cautiously. Smarter move would be to tow it there actually...
 

JHZR2

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Know what you mean, but honestly, it really depends on the use-case.... In my previous life as a mechanical designer, yeah, I would put threaded holes in a part and spec it as "M8-1.25" and the BOM would say "M8-1.25 x 50". The CAD software would insert the fastener to the correct scale/size and I didn't need to know the head size (beyond making sure it fit).

When you're doing a brake job, you use a 17mm socket or wrench to remove the bracket fasteners and like above, you don't care that the fastener is M10-1.5.

I get it that the things that one really needs to know is the socket or wrench size needed to remove a fastener. It the details do matter…
 
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An "easy out" is a misnamed tool. And it's made of hardened steel.

The good thing about your situation is it was installing the bolt, not removing a rusted-in bolt.
 
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A year or so ago I did have one caliper bracket bolt come loose (unless I hadn't tightened it properly, which is possible but unlikely). Can't remember for sure, but it's likely I used anti-seize.

Based on this discussion, I plan to use blue Locktite from now on. (Dry is not a good choice here due to rust.)

Thanks to those here who suggested it.
 

D60

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An "easy out" is a misnamed tool. And it's made of hardened steel.

The good thing about your situation is it was installing the bolt, not removing a rusted-in bolt.
And it demonstrates perfectly the typically inverse relationship of hardness and toughness. Carbide tooling manufacturers basically do nothing but spend all day every day trying to find a balance of the two, or searching for magical ways to somehow increase both simultaneously.

Think porcelain tile: it's very hard but brittle. Like a Difficult-Out (so named because they always make your life more difficult)
 

djb

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So to clear up my response,
I did not even attempt messing with the rear caliper bracket bolt, because I failed so quickly at the front brake rotor screws… the basic philips type screws that hold the front rotor to the hub… both of them broke 2 on each front rotor when trying them to remove the rotor.. The fronts were black philips rotor screws (maybe black oxide) not the stainless steel OEM ones. The rears were OEM stainless and came right out.

so I thought my easy out would shine here.. and well it didn’t 😂 and I am thoroughly discouraged from ever using another one again….
I skipped even trying to rear caliper bracket bolt because I don’t want to make it harder for the tech to remove if I can’t get it. At this point it’s not worth the risk and I’ll let the “pro” handle it.

EDIT:
The car at this current point is completely drivable and everything is tight, including the rear caliper bracket bolt that’s broken, I just can’t remove it myself.

So I’m gonna drive it right to the shop 😂 have the brake and clutch fluid flushed and that bolt extracted and replaced…

In my experience, rotor hold-down screws have a black oxide finish. They are also hard to the point of being brittle, making them extremely difficult to drill out. Pros usually just take a sledge to the brake rotor, breaking off the head, then leave the screw stub in place. People like me are bothered by that. We drill until we run out of bits or break off a bit in the middle of the screw.

Using a hand impact driver, the type used with a hammer, works best for me. Most of the time you won't need it, but use it before you round out the head. The impact vibrates the jammed fastener head and loosens the rust pressure. Immediately replace the fastener because it will be worse the next time.

I thought that metric took care of the fastener designation. A "10mm bolt" has a 10mm hex head. If you mean a 10mm nominal diameter, you say "M10" -- which is less useful in a repair context since you don't know if the head is 14mm, 16mm, 17mm, E12, E14, etc.
 
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In my experience, rotor hold-down screws have a black oxide finish. They are also hard to the point of being brittle, making them extremely difficult to drill out. Pros usually just take a sledge to the brake rotor, breaking off the head, then leave the screw stub in place. People like me are bothered by that. We drill until we run out of bits or break off a bit in the middle of the screw.

Using a hand impact driver, the type used with a hammer, works best for me. Most of the time you won't need it, but use it before you round out the head. The impact vibrates the jammed fastener head and loosens the rust pressure. Immediately replace the fastener because it will be worse the next time.

I thought that metric took care of the fastener designation. A "10mm bolt" has a 10mm hex head. If you mean a 10mm nominal diameter, you say "M10" -- which is less useful in a repair context since you don't know if the head is 14mm, 16mm, 17mm, E12, E14, etc.
Maybe people should remove and toss the rotor hold down screws. What good to they do?

What I do like and Subaru has them are two threaded holes in rotor to install & tighten evenly two bolts (not from a HF bolt assortment, as they suck) that will pop the rotor off the hub undamaged.
 

D60

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Maybe people should remove and toss the rotor hold down screws. What good to they do?

What I do like and Subaru has them are two threaded holes in rotor to install & tighten evenly two bolts (not from a HF bolt assortment, as they suck) that will pop the rotor off the hub undamaged.
Jack screw provisions are genius, this should almost be federal law (not quite as I'm not in favor of over-regulation). Toyota does it on drums, too. Smartest thing EVAR
 
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Right. There are other bolts or nuts where no lubricant or anti-seize is suggested like lugnuts or lug bolts.
When I do brakes I use all new bolts, the bolts here are usually buggered with rust. The new bolts have a material applied to them at the factory.
Napa and Rock carries them for almost everything if you want to avoid the dealer.
 
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When I do brakes I use all new bolts, the bolts here are usually buggered with rust. The new bolts have a material applied to them at the factory.
Napa and Rock carries them for almost everything if you want to avoid the dealer.
Do all/most car manufacturers recommend new bolts when reinstalling the caliper bracket?

I agree, good idea. Plan ahead.
 
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Do all/most car manufacturers recommend new bolts when reinstalling the caliper bracket?
Some do. I seem to recall reading somewhere (or maybe someone said it*) that even Ford says to replace the caliper bracket fasteners if they're removed. I only thought that torque-to-yield fasteners couldn't (shouldn't) be re-used.

* This came from a former Ford tech with a popular YT channel - FordTechMakulko (or something like that)
 
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Do all/most car manufacturers recommend new bolts when reinstalling the caliper bracket?

I agree, good idea. Plan ahead.
Many do, not just because they are not TTY bolts they are generally higher torque and can become strained with multiple use. I just had to use a Rocket socket on 2 the heads were so rusted so those 100% have to be changed. In the salt belt old nuts and bolts suck, just replace them on every job, brake, suspension, engine work the lot.

I buy 10.9 fastener assortments here, I don't bother with low grade stuff high grade can take more torque to remove. Special bolts come from the dealer.

 

1 SX

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In my experience, rotor hold-down screws have a black oxide finish. They are also hard to the point of being brittle, making them extremely difficult to drill out. Pros usually just take a sledge to the brake rotor, breaking off the head, then leave the screw stub in place. People like me are bothered by that. We drill until we run out of bits or break off a bit in the middle of the screw.

Using a hand impact driver, the type used with a hammer, works best for me. Most of the time you won't need it, but use it before you round out the head. The impact vibrates the jammed fastener head and loosens the rust pressure. Immediately replace the fastener because it will be worse the next time.

I thought that metric took care of the fastener designation. A "10mm bolt" has a 10mm hex head. If you mean a 10mm nominal diameter, you say "M10" -- which is less useful in a repair context since you don't know if the head is 14mm, 16mm, 17mm, E12, E14, etc.
You just described what transpired with the front rotors lol. Yeah all 4 front rotor hold down screws broke… using the impact hammer device to unscrew them …. it bothered me a lot, probably more then it should of so I attempted to drill them out, broke the easy off inside of the drilled out hold down screw, spent another hour or so trying to drill that out, got frustrated and fed up then called it a day… 😡 if dealer and mechanics used anti-seize I believe i would not be having this issue…

I just call bolts by their head size even though it’s probably wrong, as in the bolt that broke for the caliper bracket was a 14 mm head hex size.
I think Kia labels it as a M10-1.5 x 34mm?
 

1 SX

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Maybe people should remove and toss the rotor hold down screws. What good to they do?

What I do like and Subaru has them are two threaded holes in rotor to install & tighten evenly two bolts (not from a HF bolt assortment, as they suck) that will pop the rotor off the hub undamaged.
There has to be a reason for them though no?

I read it’s just for ease of assembly at the factory so when they put the sub frame into the car or whatever everything is tight and the rotors won’t fall off etc.?

Is that really the truth? To be honest i cannot see them preventing “warped rotors” or anything like that but if they’re there from the factory I like to keep it oem and use them…..

Put my mind at ease 😂 I’m ready to have the shop drill out the front 4 hold down rotor screws that broke while replacing the rotors…… would that be a waste of time, money and energy though if honestly the screws do nothing?
 
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There has to be a reason for them though no?

I read it’s just for ease of assembly at the factory so when they put the sub frame into the car or whatever everything is tight and the rotors won’t fall off etc.?

Is that really the truth? To be honest i cannot see them preventing “warped rotors” or anything like that but if they’re there from the factory I like to keep it oem and use them…..

Put my mind at ease 😂 I’m ready to have the shop drill out the front 4 hold down rotor screws that broke while replacing the rotors…… would that be a waste of time, money and energy though if honestly the screws do nothing?
On Euro cars that use lug bolts they definitely have a purpose, without them the rotor can get out of alignment with the lug holes. On Japanese stuff that use lug studs it is for assembly line ease only. There is a negative to them though it prevents rotating the rotors on the studs to correct run out, if it has studs I toss them.
 
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