E92 BMW Brake Disc Retaining Bolt Rounded

E92 BMW Brake Disc Retaining Bolt Rounded

Author
Discussion

HughiusMaximus

Original Poster:

694 posts

125 months

Sunday 21st June 2015
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Afternoon all,

As the title suggests... was trying to change the front discs and pads on my 335 BMW yesterday and everything was going well until it came to loosening the retaining bolt on the disc.

Its a 6mm hex bolt, and rounded as I was trying to remove it.

Any advice on how to get it out or will I justadmit defeat and take it to a garage?....

Any advice welcome!

HughiusMaximus

Original Poster:

694 posts

125 months

Sunday 21st June 2015
quotequote all
Just saw a similar thread below so feel free to ignore!!

Sorry.

imagineifyeswill

1,225 posts

165 months

Sunday 21st June 2015
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I think you,ll find the similar thread is about countersunk disc retaining screws, slightly different from yours. Ive found with these allen headed screws what often works is to hammer in a very slightly bigger torx driver.

HughiusMaximus

Original Poster:

694 posts

125 months

Monday 22nd June 2015
quotequote all
Thanks.

I beat a hasty retreat on Saturday and said I'd look for a solution and try again this weekend.

I'll give it a good blast of heat first to hopefully break the seal and then try hammering in the Torx.

Worst case I'll resort to the angle grinder as per below.

PositronicRay

26,959 posts

182 months

Monday 22nd June 2015
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I've one of these rounded hex bolts as well. I haven't tackled it yet, what's to stop me just drilling it?

andyiley

9,106 posts

151 months

Tuesday 23rd June 2015
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Ive always found the best way with things like this is to go nuclear straight away.

Drill the head off, remove the disc, if then the stub comes out great, if not grind it flat, then drill & tap a fresh hole.

AW10

4,422 posts

248 months

Sunday 5th July 2015
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Or use the corner of a chisel on alternate points around the outer face to try to "turn" the bolt. Often times the repeated taps are enough to break the bolt loose. They're usually under minimal tension which helps.

BigTom85

1,927 posts

170 months

Friday 10th July 2015
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Definitely use some impact and or heat to help break the corrosion and friction between the casting and the fixing.

Hammering in a torx could well do it, if not I find a spring loaded centre punch to mark the centre followed by a 4mm left handed drill bit works a treat. Normal the drill will bite quite quickly and withdraw the fixing.

col68

247 posts

205 months

Saturday 11th July 2015
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Bmw/mini disc retaining fixings ,always tend to heat first and then use an impact driver, once rounded by not following this procedure then it's a drill out/re tap case..

PositronicRay

26,959 posts

182 months

Saturday 18th July 2015
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BigTom85 said:
Definitely use some impact and or heat to help break the corrosion and friction between the casting and the fixing.

Hammering in a torx could well do it.
Just tackled this liquid wrench and a torx hammered in did the trick. many thanks. bow

HughiusMaximus

Original Poster:

694 posts

125 months

Sunday 19th July 2015
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I tried all the suggestions and then ended up going nuclear and using the angle grinder....

Partial stub left but no way in getting that out easily.