Show me your nuts

[CatalystV12V]

So, I’ve looked at 3 V12V’s this weekend and on two of them the brake disc fastening nuts where badly corroded.

While cosmetically not pleasing, I’m more concerned about potential safety aspects. As some may have read on one of my other recent posts, when this happened on my previous V12V AM replaced all the discs and pads under warranty. So I’m left wondering whether this is a real issue or not.. The discs themselves looked ok.

So how common is this, and is it something to be concerned about.

Edited by CatalystV12V on Tuesday 10th October 02:48

[Ghini]

Did you ask the sellers about them? Why did they not replace them, under warranty or on their own?
If the rest of the car is good enough for you, you could take the car to a dealer together, discuss it and sort it out, make it part of the deal?

[CatalystV12V]

I did ask and no response was given other than we'll look at the cost to replace [at an independent garage]. Which wasn't the answer I was looking for. I want to know whether its an issue for longevity or safety - these brakes are roughly 5k a corner so it's not something I want to get wrong.

I'm going to ring Works Service today and ask them.. I'm still interested to know how wide spread this is.. So please let me know if your car has this 'problem'.

Thanks!

[kevin_cambs_uk]

I am pretty sure mine look similar, service at Works in April, never mentioned it but they did notice 8 of my wheel bolts were cracked, so I had all of them replaced.

Kev

[CatalystV12V]

Thanks Kev!!

[LTP]

kevin_cambs_uk said:

I am pretty sure mine look similar, service at Works in April, never mentioned it but they did notice 8 of my wheel bolts were cracked, so I had all of them replaced.

Kev

CatalystV12V said:

Thanks Kev!!

Sorry to butt in here, but just to be clear Kev is referring to the road wheel bolts, not the nuts attaching the CCM rotors to the hubs, as Kev's V8V has steel rotors. I know this as I shared a coffee with Kev at the recent AMHT event at Gaydon.

If this was already clear then....



edited to add

Hi and sorry for sticking my nose in, Kev!

Edited by LTP on Tuesday 10th October 12:02

[CatalystV12V]

Thanks LPT!!


I spoke to Works Service this morning and they said this was expected and nothing of major concern...

[cayman-black]

If mine looked like that I would be changing them! The wheel and calliper looks unloved to me also.

[SHIFTY]

The problem is with the rear of the ceramic disc do not want to put you off but have a look at the pictures on the attached (ignore most of the comments):-

https://www.pistonheads.com/gassing/topic.asp?h=0&...

[CatalystV12V]

Hi Shifty

Thanks for that link… this ties in with my experience of AML replacing discs with rusted nuts and seems to explain why.
The corrosion in the above picture is on a low mileage car, 13k, so I think this point to an issue that means I need to walk away.

[vulcan26]

My DBS discs look like this. It’s a cosmetic thing, unless the bolt heads at the inside of the disc have corroded so badly they have come off. Apparently one or two are OK but more than that becomes an issue.
I looked into if the bolts can be replaced, and found a source in the USA, but I’ve struggled to remove the bolts, they seem stuck into the sleeve that goes through the carbon disc. I’ve love to hear of anyone who has had a similar experience and who has managed to remove the seized bolts……

[CatalystV12V]

Hi Vulcan. Thanks for the post.
I find this subject quite concerning especially as I’m looking at V12Vs as we speak. Most have this issue to varying degrees.
As you say I think the real problem lies on the backside of the disk which is difficult to view even on a ramp.

Some pictures and comments I’ve seem to indicate that once corrosion sets in, the formation of rust can cause disks to crack. Also IIRC this issue mainly effects 2009/2010 cars. Which model year is your DBS?

[vulcan26]

its a 2009. it is just about possible with the wheel off to see (or better feel) the bolt heads at the rear of the disc. I take some comfort in the fact that with the bolts effectively seized into the bobbin sleeve, so it isnt going anywhere, but you are right, this can lead to cracking of the disc itself.

There are other threads about other marques of this era having the same issue (Lambos and Ferraris I think?) and its clearly something to be aware of. I know at some point I'll need to replace the discs in any case, so I'm just keeping an eye on them at the moment.