A4 QUATTRO BRAKE UPGRADE TO S4 BRAKES

[Papar000]

Hi all,

i have an opportunity to buy a set of 2010 s4 front and rear rotors with Calipers. Are they a direct fit to my 2010 a4 avant? Are they worth the upgrade

[shreddykrueger]

Hi all,

i have an opportunity to buy a set of 2010 s4 front and rear rotors with Calipers. Are they a direct fit to my 2010 a4 avant? Are they worth the upgrade

yes direct fit, easy swap. you'll gain some additional braking power and larger front calipers/rotors, I think its worth it if the price is right. Im actually in the process of doing s4 brakes on my avant

[Nano909]

Ew I wouldn't install S4 calipers, they're still single piston and definitely not worth the effort. I would however swap the rear brakes to S4.

[Papar000]

so the front are not that different? whats the difference with the rear?

[Shane Horning]

I would definitely recommend swapping over the complete set. I did on my a4 and made a good bit difference

[Nano909]

I would definitely recommend swapping over the complete set. I did on my a4 and made a good bit difference

Rear is bigger at 330mm and the rotor is vented vs our skinny solid ones.

[isesoteric]

The fronts are different, the only different part though is the brake carrier. the stock rotors are 320mm and the S4 are 345mm, even though the calipers are the same the stopping force is greater.

the rear calipers from the S4 are bigger in diameter and thickness because they are vented.

[A4B8 2.0tfsi]

Brakepads will do a hell of a lot more, than disc size/width. I can lock my wheels with standard brakes and Red Stuff pads, without any problems, so...... Bigger brakes, will probably also lock up my wheels without any problems. It's a pretty pointless change, unless you have a lot of cash you need to throw away. Looks better, but is not needed for stopping your car.

[Nano909]

Brakepads will do a hell of a lot more, than disc size/width. I can lock my wheels with standard brakes and Red Stuff pads, without any problems, so...... Bigger brakes, will probably also lock up my wheels without any problems. It's a pretty pointless change, unless you have a lot of cash you need to throw away. Looks better, but is not needed for stopping your car.

Do some canyon runs with those stock brakes and Reds and see how they hold up.

[Spawne32]

Brakepads will do a hell of a lot more, than disc size/width. I can lock my wheels with standard brakes and Red Stuff pads, without any problems, so...... Bigger brakes, will probably also lock up my wheels without any problems. It's a pretty pointless change, unless you have a lot of cash you need to throw away. Looks better, but is not needed for stopping your car.

Actually, the amount of braking power proportional to the weight of the car is particularly undersized, particularly at a high rate of speed. While obviously if you put better brake pads for an intended purpose on any car, you will improve braking performance. But larger brake calipers, pads, rotors and more clamping force will provide better braking with less effort. Unfortunately S4 brakes are largely not that much different in comparison to A4 brakes.

[isaac7486]

yes direct fit, easy swap. you'll gain some additional braking power and larger front calipers/rotors, I think its worth it if the price is right. Im actually in the process of doing s4 brakes on my avant

i have all the right stuff but the 330mm rear rotors won’t allow me to fit both bolts into the carrier without touching the rotor. it’s a little less than half an inch off from the second bolt hole.


Sent from my iPhone

[isaac7486]

i guess if anyone can help, i got the fronts on without even touching the dust shield, rotors appear to be about an inch bigger than stock a4 fronts. but i CANNOT get the rears on without fabbing up something. all the components of the rears match up to an s4 but i had zero luck.


Sent from my iPhone

[Smac770]

Something must not be the right part. The dust shields are the same for A4 quattro (1KW,2EH) 300x12 and A4 quattro (1KP) / S4 (1KE) 330x22. A4 fwd has different rear dust shields. Is there any part number on the caliper carrier bracket to review? The rear S4 carriers are 8K0 615 425 A left and 8K0 615 426 A right. These are the 1KE black painted ones. The 1KP unpainted ones are without the A. The upper and lower carrier to wheel bearing housing bolts are the same for 300x12 and 330x22.

[isaac7486]

Something must not be the right part. The dust shields are the same for A4 quattro (1KW,2EH) 300x12 and A4 quattro (1KP) / S4 (1KE) 330x22. A4 fwd has different rear dust shields. Is there any part number on the caliper carrier bracket to review? The rear S4 carriers are 8K0 615 425 A left and 8K0 615 426 A right. These are the 1KE black painted ones. The 1KP unpainted ones are without the A. The upper and lower carrier to wheel bearing housing bolts are the same for 300x12 and 330x22.

hmmmm, i painted them after i bought them so i will have to dig around and try to figure it out


Sent from my iPhone

[Smac770]

Some visual samples of the carriers in place:
https://youtu.be/Kl5JdnO1sbg?t=256
https://youtu.be/dDy1pqji804?t=210

I presume you mean the carrier is contacting the outer circumference of the rotor when you try to position it such that you can put both bolts in? Not talking about an issue of the friction surfaces contacting the carrier? The latter is just the normal you have to put the lug nuts back on with a spacer (14mm wrench e.g.) to force the rotor to sit on the hub fully while you get the carrier and caliper on.

Watched more of the ShopDAP vid; must be nice to be able to remove the 330x22 rotor without removing the carriers.

[isaac7486]

it’s really strange. you can see in the photo below that’s the side closer to the camera or more to the right ha hitting the top of the rotor while also hitting the friction side. and never mind. the photo is “too big”. sick.


Sent from my iPhone

[isaac7486]

IMG_0049.jpg


Sent from my iPhone

[bb-tt]

it’s really strange. you can see in the photo below that’s the side closer to the camera or more to the right ha hitting the top of the rotor while also hitting the friction side. and never mind. the photo is “too big”. sick.


Sent from my iPhone

IIRC the s4 bracket gap for rotor is wider than the a4 there is another post that shows the measurements if you search sounds like you have wrong bracket. The s4 set up bolts directly on with no issues.

[isaac7486]

IIRC the s4 bracket gap for rotor is wider than the a4 there is another post that shows the measurements if you search sounds like you have wrong bracket. The s4 set up bolts directly on with no issues.

hmmm. i’m at work for the day now but i will have to look around and see if i can spot a difference from mine. from first glance you can immediately tell the difference between my stick carrier brackets and the ones i bought but maybe they are wrong.


Sent from my iPhone

[isaac7486]

IIRC the s4 bracket gap for rotor is wider than the a4 there is another post that shows the measurements if you search sounds like you have wrong bracket. The s4 set up bolts directly on with no issues.

okay okay. i’m at work for the day now but i will have to look around and see if i can spot a difference from mine. from first glance you can immediately tell the difference between my stick carrier brackets and the ones i bought but maybe they are wrong.


Sent from my iPhone

[Smac770]

I think you're talking about the problem you get when you don't compress the rotor onto the hub as I've already referenced.

temp brake.jpg

I thought you were talking about contact along the green orientation. But along the red orientation, yeah, normal. Make sure the rotor is fully pressed on by using lug bolts and spacers. You can't turn the lug bolts on fully without a spacer to replicate the wheel; 14mm box end wrench works perfect.

[isaac7486]

I think you're talking about the problem you get when you don't compress the rotor onto the hub as I've already referenced.

temp brake.jpg

I thought you were talking about contact along the green orientation. But along the red orientation, yeah, normal. Make sure the rotor is fully pressed on by using lug bolts and spacers. You can't turn the lug bolts on fully without a spacer to replicate the wheel; 14mm box end wrench works perfect.

if you can notice on the other side of where you marked it up of the where the rotor is hitting, it would be hitting on the red line since the opposite (the side you marked up) bolt is already in. the clearance just doesn’t seem to be enough to fit the diameter of the rotor but the caliper and pad fit the rotor, and the rotors are correct


Sent from my iPhone

[adamazing]

if you can notice on the other side of where you marked it up of the where the rotor is hitting, it would be hitting on the red line since the opposite (the side you marked up) bolt is already in. the clearance just doesn’t seem to be enough to fit the diameter of the rotor but the caliper and pad fit the rotor, and the rotors are correct

You're saying the rotor will go from hitting the outboard side, to the inboard side? Is this because you've already fully pressed the rotor onto the hub and that's what happened?

I'm in agreement with Smac, in that it looks like you need to further press the rotor onto the hub so that it moves inboard some more.

[isaac7486]

i’ll give it a go soon, i ordered different brackets as well so ill be extra optimistic


Sent from my iPhone

[isaac7486]

got bored and started messing around, something i didn’t wanna do since brakes are important. turns out the “professional” i brought it to had the the WRONG bracket on each side. i guess he thought they were universal even tho they clearly look different. thanks guys image-2021-07-22-20:12:44-606.jpgfor pushing me to get off my butt and finally figure it out, love y’all

[Smac770]

Heh, at least it was simple. Yeah, the fronts are mostly single carrier bracket for left and right (two 125); the S4 and Q5 345x30 before Jun 20 '11 use separate brackets for left (125) and right (126).

But the rears are always separate brackets for left (425) and right (426), be it 300x12 or 330x22.