Rounded allen bolt (disc brake)

[Jimbob]

Started to overhaul the brakes yesterday, unfortunately the c#nt who fitted the discs rounded off the locating allen bolt on one of them!

Going back tomorrow with a dremel with the intention of cutting a few slits in the head of the bolt to unscrew with a screwdriver bit.

Does anyone have any other suggestions of how to get it out?

[Speedtouch]

MIG-weld a bolt to it - the heat will help shift it.

[capri_rob]

The animal method is to smash the disk off with a persuader - it wont take much

You can then grab the stub of the bolt with molegrips/stillsons or get heat on it and get it out.

Quick and easy

Or you can piss about with it for ages trying to remove it with the disk in-situ

[Jimbob]

Thanks for the fast response, forgot to mention though no access to a welder..or at least until next week

Beat the disc off, if all else fails I guess!

[Speedtouch]

You could drill the bolt and use an Easy-out, which can be got quite cheaply from E-bay, etc.

http://www.ebay.co.uk/sch/i.html?_from= ... w=easy+out

[capri_rob]

I had to to this on my previous E30 - the disk was scrap anyway - one smack on the disk with a lumphammer and it broke the head of the bolt off

a Dousing with penetrating oil and some good molegrips and it was out in a few minutes

Just make sure you copper-grease the new ones and just nip them up rather than bollocking them right up as tight as they'll go like most people seem to

[Jimbob]

Thanks for the comments guys, will also buy one of those extractor kits just for the sake of it at those prices!

[Speedtouch]

Beware with the cheaper kits, as the thinner ones are made of chocolate!

[votivequagmire]

In the past whenever I've had this problem, the best method I found for removing brake disc bolts was to soak it in WD40 first and let it penetrate. Then, using the nearest size to the hole torx bit, gently tap into hole. When it's seated right, you can then slide on the bit holder, unless you used that tap on. Ratchet on and in almost every case I've come across, the screw can normally be extracted quickly and cleanly.

[Brianmoooore]

Just take the calliper and bracket off, turn the disc so that the bolt is opposite from where the calliper was, and give the disc a good smack from behind with a lump hammer, but hold a piece of plywood or 2 x 1 between the disc and hammer.
Won't hurt the disc, won't hurt the hub. but will tear the head off of the bolt and remove the disc. The remains of the bolt isn't usually seized, and can normally be screwed out with grips.
The attempted use of stud extractors usually ends in tears.

[macas]

Just smack a slightly oversized flat headed screwdriver into the void and twist the screw out,simples,done this loads of times!

[sag]

The method iv used in the past on other cars , is using a centre punch and a hammer (if you are talking about the little grub screw which holds the disc on to the hub)
But Not sure on a e30 if it has enough meat on the edge of the bolt

[rix313]

Always pisses me off when people murder up disc retaining screws. Like the disc is going to fall off whilst clamped solid between the wheel and the hub

[scjimbo]

The way we extract screws like this at work, and the way I do it on my car is to drill off the head. Take a drill slightly bigger in diameter than the body of the screw. Get out you battery drill. Set it to a nice slow speed. Using what's left of the allen key socket in the screw as a centre start drilling. Your aim is to just break into the body of the screw and remove the head. Once you have taken the head off remove the disk and get some mole grips on the remains of the stud. Normally once the head is gone the stud will release. If this is still rusted into the hub. Drill a small hole right through the screw being careful not to damage the bearing behind the hub. Spray with pocket rocket and get an easy out on the little bugger.

[TDSCHRIS]

Hammer a torx bit into the rounded out Allen key hole

[votivequagmire]

Hammer a torx bit into the rounded out Allen key hole

Glad that someone else uses the same method as myself

[Brianmoooore]

Just smack the disc from behind and have done with it!

[Speedtouch]

Doesn't this method risk buckling the disc or damaging the wheel bearing?

I would only use it as a last resort.

[Brianmoooore]

Doesn't this method risk buckling the disc or damaging the wheel bearing?

I would only use it as a last resort.

Not in the slightest! Take the head of the bolt clean off - it's only a little 6mm bolt.

[mcbonio]

These are all kinda brute methods smashing and hammering things guys....

All you need to do is take a small punch, like what you use to make a pilot hole/dent in materials before you drill.. like this.



Position it on the outside flat part of the screw head and tap the screw out anti-clockwise. Couple of light taps does it. Takes no effort at all.! I've even used a small blunt chisel before today.

[HairyScreech]

Just drill the head off and forget about the rest, does anyone actually use the retaining screws?
I think the last wheel bearing i fitted didn't even have a hole for the retaining screw.

[maxfield]

Just take the calliper and bracket off, turn the disc so that the bolt is opposite from where the calliper was, and give the disc a good smack from behind with a lump hammer, but hold a piece of plywood or 2 x 1 between the disc and hammer.
Won't hurt the disc, won't hurt the hub. but will tear the head off of the bolt and remove the disc. The remains of the bolt isn't usually seized, and can normally be screwed out with grips.
The attempted use of stud extractors usually ends in tears.

By far the best method, takes 2 minutes. Stuff pissing about getting the drill out etc.

[Jimbob]

Just drilled it out in the end, tried to hammer it off but either too weak or couldn't get enough of a good swing into it. Good to see the community spirit though with so many responses

[Silverfang]

Mine sized solid in one of the hubs, evenually used a reverse fluke drill on the head and drilled it off, slight tap and it came free.

It's still stuck in there after I tried to remove it with mole grips, so it'll be swapped off when i replace the front bearings.

[spiny]

Just drill the head off and forget about the rest, does anyone actually use the retaining screws?
I think the last wheel bearing i fitted didn't even have a hole for the retaining screw.

This is what I did, I drilled them out and left the 'stub' in place to hold the new disk while bolting the wheel back on.
I did buy a set of replacement screws, but bought the wrong ones by mistake, and I haven't got round to ordering the right ones.

the wheel does a good job of holding the disk in place anyway

[SGP]

A little dab of copper grease on the new one and just nip it in hand tight