Brake disk bolt

[Silverzedtom]

How likely is it that I’ll have to drill out the bolt holding the disk on when changing disks? I’m thinking I might tackle this next week but want to have everything I need or might need there ready so if they are often a pain I’ll order some.

Anyone know off the top of their head if it’s a 7mm allen needed? I did check once but can’t remember for the life of me

[Nash3vans]

I've come across this problem a few times in the past, what I do is use a centre punch or a pointed chisel on the head of the screw and tap it round with a hammer.

[Steve84N]

Try it today, only need to get the wheel off to see it.

[Gaffa22]

Yes agree with Nash3vans. If it does round off use centre punch or chisel.
You could try it before replacing discs as you don't have to re fit it, the wheel bolts hold the discs on

[kis]

Have a go today? If it feels solid don’t push it. Spray some penetrating fluid and give it a few taps. Then have a crack at it again later

[Silverzedtom]

Cheers guys. I’m not with the car today but will check one evening this week. I can always order a set if I do have to mess around with hammers and punches.

[patriot66]

From my experience if the discs have been on a while then unless the bolt was tightened with a little Coppaslip applied (like I do ) then chances are high they will be corroded tight. Soak it with penetrating fluid, insert an old allen key and hit it hard with a hammer to break the corrosion, then try with an allen bit on a ratchet (allen keys bend too much) and be firm with it. If it won't budge then don't force it as it will round out before it loosens. Go and buy a Silverline Impact Screwdriver on Ebay for about £10. I got one a few years back and it's never failed me yet. Brilliant tool !

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Make sure you use a hardened impact bit. If that doesn't budge it then heat the bolt with a blow torch and then impact it !

[grumps]

Go and buy a Silverline Impact Screwdriver on Ebay for about £10. I got one a few years back and it's never failed me yet. Brilliant tool !

This is my tool of choice as well. There isn't much stays seized with a touch of heat and an impact driver.
I recently treated myself to a Hitachi electric one as well for undoing those slotted screws in old joinery where the slot normally gets chewed up by a flat screwdriver, highly recommended!

[Lance]

OP, tip, use a good quality allen key on the retaining bolt. I didn't and the first disc retaining bolt chewed and was a real effing hassle. The other three were no problem with better quality, better fitting tools.

Caliper carrier bolts are 16mm, the fronts were very tight and needed a bit of extra leverage. For me the 16mm ring spanner was the preferred option.

All four discs had been on for at least 40k miles.

[Greg 01]

Hi guys .
I've had this a few times on my e46
Drill the head off the bolt and the disc will come off the take the bolt out with some mole grips once the disc is off the bolt is not hard to undo as it's not tight anymore .

[Chris1981]

It's a 6mm allen bolt... did all 4 of mine at the weekend without any issue, plenty of penetrating fluid and leave it to soak for as long as possible, preferably an hour or so... hopefully you'll be alright!

But failing that any of the methods above would help remove a stuck bolt, I've drilled them out before but the impact driver would be much quicker and if i had one would be my preferred method if it came to it!

[Silverzedtom]

It's a 6mm allen bolt... did all 4 of mine at the weekend without any issue, plenty of penetrating fluid and leave it to soak for as long as possible, preferably an hour or so... hopefully you'll be alright!

But failing that any of the methods above would help remove a stuck bolt, I've drilled them out before but the impact driver would be much quicker and if i had one would be my preferred method if it came to it!

hopefully I’ll have the same luck as you! I know I’ll be ok on the front nearside as I had a new wheel bearing last year.

Glad to hear it’s a 6mm as I’ve loads of those.

I’ll make sure I let some penetrating oil sit for a while

[TempusFugit]

It's difficult to drill out, I tried and failed. In the end, I used a good quality punch/chisel at the right angle and a good hard hit to free it.


Also if all goes badly, new hub/bearings are not all that much.