Technical Caliper bolt

[GJay]

Hey guys,
I have a 2007 Panda 100hp. I started the job of replacing my rear brakes as my pads were almost down to the backing plate and the discs weren't in great shape either. Anyway, everything was going to plan until I came to the 8mm Hex bolts holding on the caliper bracket. Cleaned out the gunk and the Allen key just spun and the bolt went nowhere, same thing happened with both passenger side bolts (Never even attempted drivers side).
I'm not very experienced in this type of work but I'm willing to try maintenance/ repairs I'm confident enough about after watching several YouTube tutorials.
My question is, is there a tool anyone could provide a link to, that would go about extracting these if they have been rounded? Also if someone could provide a link to the bolts I would need to replace these once removed.
As I needed the car I just went with installing the new pads for the meantime. I'm sure I could go to a mechanic to get them removed but I would rather take care of it myself to save money and there's also the small matter of pride lol. Also I don't have a drill so please keep that in mind.
I also have discs and pads to do the front soon and I'm guessing the front bracket uses the same bolts?

Many thanks!!

 

[vexorg]

I'd be tempted to remove the hub or strut from the car for better access.

I'm not sure the irwin style easyouts will work, worth a try but may just chew through the bolt heads.
Failsafe option is to weld a nut to them and fill the centre.

 

[koalar]

First of treat it as a learning opportunity

You now know how much force is too much

From this end it's hard to know for the best, as we don't have as much information as actually being there

Was the head already damaged by a previous repair

Or was it so tight it eventually rounded

I suspect the problem was cause by both the Allen key, they are normally not well size, fairly soft and are difficult to keep square

And they are normally fitted with nut lock

Too late now but a few wacks with a hammer first plus a lot of heat(plumbers blow torch) and a Hex socket would normally prevent this in the first place,

It is what it is we have all been there,

 

[koalar]

There are quite a few different options

The easiest is weld a nut on the top, both gives it a thermal shock and easy leverage

An extractor is the last resort if it breaks you can't drill and rethread

If it's not supper tight after heating then you can put the Hex in the head and use vise gripes

Hammer an chisel/punch and knock it round

Cut the heads off, heat and use vice grips

Penetrating oil will not help from the front as there is no way in until is loosened a bit, some at the back.will help

File flats and use vice grips

Cut a slot and use an impact driver

Which might be my first try just because they are on the top of my tool box

Or maybe cut a slot and chisel it round

There are are specialised tool but have never tried them

https://www.google.com/search?q=damaged+hex+bolt+extractor&client=ms-android-huawei-rev1&sca_esv=586305682&tbm=isch&sxsrf=AM9HkKnsgEt1AhaBYCgL-N-dZLPPt4jJqA:1701270901838&source=lnms&sa=X&ved=0ahUKEwic9ZT-v-mCAxVmRkEAHX2VA-gQ0pQJCCA&biw=360&bih=637&dpr=2

But it's rare I go beyond heat plus a hammer and chisel and rarely reach for the welder as its a pain for me to get to

 

[jrkitching]

There are quite a few different options

One of which is to carefully drill off the head of the sliding pin; this will allow you to remove the caliper, leaving the pin attached to the reaction frame.

Once you have the frame on the bench, there are lots of good ways to unscrew the remains of the pin from the body of the frame.

 

[koalar]

The original bolts came with thread lock, heat is your friend if it does not loosen easily

I bought a set of these, one of the worse purchases I have made. They do work and grip well. But the tighter you screw them in the more they expand the metal outwards, so if the head rounded because it was tight, these make it tighter still

These work well, at least they do for spark plugs, I have never tried in bolts

I have tapped in a normal torx bit before now and works quite well,

This are specially made for the job. Never tried them, They basically cut a new head, some like the grip edge brand are very expensive

However you still need to break the bond between the two parts either mechanically, heat or both first to stand the best chance

 

[jrkitching]

I bought a set of these, one of the worse purchases I have made.

I've got a set of these as well.

I've tried using them on numerous occasions and, with one exception, they've proven to be completely useless. I never seem to manage to drill the hole to the correct size, so the easyout is either one size too large, or one size too small. Then I drill the hole a bit wider, and the one that was too tight is now too loose.

But I did once manage to extract a sheared spark plug using the big one; it sheared in such a way that the hole was already there and it fitted perfectly!
I put a greased cloth threaded on a string down the hole first, and since I'd accounted for all the parts, took a chance on not removing the head - the engine ran for another 80k before I sold the car.

So I guess that paid for the set.

 

[vexorg]

I was thinking more these:

 

[jrkitching]

Those are sometimes useful when you have clear access to the bolt head, but I'm not sure they'd work in this application, as IIRC the head of the pin is recessed into the caliper body - which is probably why an allen fitting is used, rather than a bolt.

 

[koalar]

Your not alone

This guy had a fight with the rears on a 100HP

He talks through the solution he used but no video

Unfortunately removing the whole assembly does have its own risks as the brake lines can also be a fight

 

[GJay]

Hey guys, really sorry I've not been on sooner to check out my replies but I am staggered by how many replies and helpful people there are in this forum. A massive thank you to you all.
There is a lot of information to read through and absorb which is amazing.
I will try to digest it all and get back to yas with some follow up questions.
Again, anazing!!