B9 S4/5 brakes on my B8.5

[Stickystuff]

Hi all, I’ve recently acquired a 2012 A4 moving on from my 2005 A6.

But I’ll be changing a few things on this. My question is, does anyone know of the B9 S4 Rear brake calipers and carriers will fit on the B8.5?

I know the mod needed to get the front to work but as mine isn’t a Quattro I want to balance the brakes out. I’ve found a set on eBay that are all 4 calipers but I didn’t want to buy them if the rears won’t fit. I’m not sure if it’s a conversion anyone has done and couldn’t find much info on it.

Otherwise I’ll look for just front B9 calipers and then a set of B8 rears

Any help will be appreciated.

 

[Simon]

The B8 S4 rear brakes are the same as the RS4 and a direct fit, I've not seen anyone fit B9 rears.

 

[Darren92]

Calipers alone will not suffice, you need carriers too.

 

[Stickystuff]

I know that about the carriers I just refer to them as a whole because most of them are sold on eBay with carriers. I’m trying to figure out if I can fit the B9 calipers and carriers to my B8. There is a set on eBay with both front and rear, the brake discs are the same dimensions but it doesn’t mean they bolt on the same. I suspect they do considering the front calipers fit but you need spacers to work on the discs where as the rears might be the same but you can’t fit spacers on them.

 

[Simon]

I have B9 S4 calipers on my B8 - when I was researching that upgrade at no point did I find ay suggestion that the carriers were a direct fit.

 

[Stickystuff]

But you have an S4 so already have the 330mm rear brakes.
I think I’ll just find a pair of B9 fronts and then a B8 set of rears and then at least I know there should be no fitment issues. I appreciate everyone’s help.

It will need to be next month I’ve just ordered a tow bar and wiring kit which is more essential than nice looking brakes.

 

[Simon]

It might be that for your rears you just need the S4/RS4 carriers and existing calipers to fit the bigger rear disks. The B9 S4 front upgrade does three things, 1. Allows you to fit bigger discs, 2. Weighs less than the standard calipers* 3. Looks cool.

* this is true for the B8 S4 calipers vs the B9 S4 calipers it may not be true for A4 calipers

 

[Stickystuff]

I’ve got solid rear discs so need both calipers and carriers. If I can find a good deal I may take a punt on the B9 calipers all round and see where it takes me. I’ve looked and the rear discs are the same dimensions as the B8/8.5 so the offset etc is the same. It’s just the bold pattern might not be. Watch this space next month I’ll see what I find

 

[Stickystuff]

So I've just found a Thread on Audizone and the B9 carrier has a different bolt spacing to the B8/8.5 so It looks like I will be getting some B8 rear calipers. They did however mention that the servomotor is different on the 8 and 8.5 so need to make sure I get 8.5 calipers. Worst case I would swap the servo over.