Minimum rear brake disc thickness before replacement

[Gary687]

Hey guys

Random question here (and I've searched and can't seem to find the answer unless I've had a 'boy look'!) but does anyone know the minimum thickness of the rear brake disc before it needs to be replaced please??

Cheers

G

 

[Parisien]

Gary...if in doubt, best to change them .....now very much cheaper than before, also is there noticeable lip on the edge?


P

 

[Emtee]

There's a wear indicator notch on the disks. Look around the edge and you'll see it, but whether you're down to the notch or not quite, if you're starting to get brake vibration it's probably wise to change them as you may have un-even wear / disks out of balance. If you have vibration, but with plenty of meat left, you could consider getting them skimmed, but it needs to be done properly to avoid making things worse.

 

[MUC3200GT]

on the 3200 minimum rear disk thickness is 26mm excentriciy 0.05mm (as far as I remember thickness is also graved in the disk itsself, readable only when the outside is not yet corroded).
4200 should be the same.

 

[Gary687]

Awesome guys thanks for the replies.

At present there's no lip to speak of and certainly no degradation in braking - no vibration, no apparent uneven wear etc and the 26mm seems to tie in with the Ferrari recommended measurement so all is currently good.

The reason I asked is that my baby is due it's service in January and apparently, according to the long-term previous owner and the acres of paperwork I have with the car, the pads and discs have never been changed (60,000kms) so I was assuming I'd be needing them. The research done by the fine fellows on here re-the replacement discs and pads means I was going to source them from the UK and get them shipped to Oz and save (literally!) many thousands of $$ and have them ready for the service in January.....but I don't think I need them yet

Cheers once again

Gary

 

[Parisien]

Do check they are working efficiently Gary....or was he very lightfooted?!

Also.....but more applicable over here, no pitting or rust degradation due to long term weathering or them not working as they should?


P

 

[mjheathcote]

From my PPI report:

Front brake discs 31.5mm thick. New 32mm/Minimum 30mm.
Rear brake discs 27.5mm thick. New 28mm/Mimimum 26mm.

So yes minimum 26mm for the rear brake discs.

 

[Gary687]

Thanks for that guys. Turns out the front is 30.5mm and the rear is 26.5mm so getting mightily close to the minimums both front and rear. Looks like I'll be onto the 'brake solution' thread to find out where best to source the discs from soon!!

Anyone bought any recently and if so, from whom?

Cheers

G

 

[Gary687]

As a side thought, I never realised the difference between new/replacement time was so small so as I am 0.5mm away, that would equate to a quarter life left on them - which in my kms terms would be about 15,000kms - or another 18 months of motoring!!

Not sure what to do now especially as the braking is showing no signs of wear etc

G

 

[mjheathcote]

When the report was carried out last year before I bought my car, as an approximation the discs where 25% worn, 0.5mm used from 2mm available.
As she had done 11,000 miles from new at that stage, you could then estimate the disc life to be around 40,000 miles.
So yes, 0.5mm would be around 15,000 kms.
Very approximate though!

 

[Geofflyn]

As a side thought, I never realised the difference between new/replacement time was so small so as I am 0.5mm away, that would equate to a quarter life left on them - which in my kms terms would be about 15,000kms - or another 18 months of motoring!!

Not sure what to do now especially as the braking is showing no signs of wear etc

G

Gary if you have had 60,000 km out of the original pads and rotors then your car must have been driven very sparingly. I think that's a great life and if you get another 15 k you should be a happy camper.

 

[Gary687]

I certainly shall be!! As ever guys, thanks for all the replies/advice/opinions - all are truly insightful and helpful!

Cheers

G