S4/RS4 brakes on to an A4

[docurley]

Well lots of people ask this question and load ask it after they buy the brakes so as I'm doing the conversion with RS4 brakes (they mount the same as the S4) I thought I would do a what’s needed and what wont work thread.


Q: Will S4 or RS4 Callipers mount on to the A4 Hub's?
A: No

Q: Can you get them to fit?
A: Yes

Now you want to know how and I hope to have the answer with some info of what you need to do.

First of there are no current carriers on the market to allow them to mount on the A4 hubs so you need the S4 hub's to make this work with the drive shafts.

Now if you are FWD will make things very easy for you guys as your flange on your gearbox is a 108mm flange where as on the Quattro gearbox the flanges are only 100mm which means the S4 drive shafts will not fit. Before you think all is lost there is a way round this (pain in the **** but you do have an option). Basically you need to get hold of some FWD flanges which will just pop out with a crow bar (So I'm told).

Then all you need do is swap the flanges over from your Quattro gear box with the FWD flanges then the S4 drive shafts should all line up and bolt together.

I will be confirming all this at the weekend as Siena and me will be doing this at the week end as I have a almost dead CV joint and a couple of RS4 legs sitting around ready for the swap with all the RS4 brakes to match.


I got my FWD flanges from Byzan (thanks myman)for my 1.8TQ and they fit the RS4 drive shafts perfectly, so on Saturday it should only be a case of popping my flanges out and pushing these in.

RS4 ARB

RS4 leg and as you can see it's all Ally

 

[Broken Byzan]

Nice work Dave, where are the calipers? I wondered what the difference was on the fitting tabs etc.
Good job you asked for the flanges when you did, i gave them to one of those pikey scrap collectors today, got rid od 2 boxes,my old engine block, a flywheel etc etc

I watch with interest, as i love these challenges.

 

[docurley]

Not sure anyone’s interested in this but I will post it anyways

Callipers are all in a box and don’t they weigh a ton need my boy to give me a hand they weighed so much.

What you mean by Tabs?

 

[Broken Byzan]

Where they bolt to the uprights,as we know they are different from A4 ones, i wondered how much different they were is all

 

[docurley]

Ahh ok I will line up the stock callipers with the RS4 legs to see what the difference is.

 

[Andy.B]

I watch enviously to see how you two get on good job

I have to ask the question though... surely it would be cheaper to get some brackets made for the application? I know not in your case doc as you had the whole car but for anyone else.... the suspension must cost a fortune from scrappys and stuff or am i wrong lol

 

[aragorn]

i'd imagine that the carriers for the calipers would be quite difficult to create different versions of as they're quite a complex shape?

i dont know if the RS4 calipers are axial mount but the S4 ones arent and have normal sliding carriers, RS4 ones may be 4 pots? and may have axial mountings which would make it reasonably easy to fabricate brackets up as you do with porsche calipers etc but if they are lug mount it gets rather tricky!

If there was a reasonable offset difference you could make an adaptor plate but i doubt this is the case meaning its probably cheaper to get a pair of s4 legs and fit them with the calipers. I'd imagine if you did this job at the same time as fitting new suspension arms or cv's as you have done it will be quite time efficient too!

 

[Siena]

I carried out the RS4 brake conversion today.

RS4 calipers are axial mounted, pretty much like regular A4, only much bigger.

They are twin piston, and the mounting bolts are also larger, and spaced further apart than on regular A4.

RS4 brakes will only fit RS4 / S4 uprights.

 

[Broken Byzan]

Did you do the 'Box too??

 

[docurley]

Nah that's on hold for some time, anyways here's the pic's of the different parts.

Here you can see the two Callipers next to each other and the RS4 units are huge.

 

[Andy.B]

Those RS4 calipers are huge for cast ones, what size are the discs? Ahh thats a ****** that they are lug mounted would have been easy to fabricate supporting brackets. Good job lads looking like good work so far, are there any more pixs?
What has happened to the other pix Doc?

 

[Broken Byzan]

What discs and calipers did yo remove?

Fancy selling them if better than std, as mine are **** at the mo !!

 

[Siena]

Those RS4 calipers are huge for cast ones, what size are the discs? Ahh thats a ****** that they are lug mounted would have been easy to fabricate supporting brackets. Good job lads looking like good work so far, are there any more pixs?
What has happened to the other pix Doc?

Discs are 32 x 360mm.

 

[Siena]

What discs and calipers did yo remove?

Fancy selling them if better than std, as mine are **** at the mo !!

Calipers are single piston, same as on my V6, not sure what yours would be, if they're the stock 1.8 SE.

Discs are 280mm.

 

[Broken Byzan]

yeah i have stock 280, i could do with at least 288 and proper caipers. And now one of my rears has decieded to ****** seize so i have little handbrake and a scarily poor peddle feel. And to make matters worse its MOT time grrrrr. Ah well gearbox out wednesday ,so maybe i will attack that cailper, i hope working it out,cleaning and rewinding a few times will help.

Anyway wicked news, i bet his car handles and stops better with less unsprung weight etc

 

[Siena]

yeah i have stock 280, i could do with at least 288 and proper caipers. And now one of my rears has decieded to ****** seize so i have little handbrake and a scarily poor peddle feel. And to make matters worse its MOT time grrrrr. Ah well gearbox out wednesday ,so maybe i will attack that cailper, i hope working it out,cleaning and rewinding a few times will help.

Anyway wicked news, i bet his car handles and stops better with less unsprung weight etc

I doubt the unsprung weight will be less.

While the strut itself is aluminium, and may be lighter, I handled the discs and calipers, off the RS4.

They are really beefy, no lightweight there!

 

[jcb]

are RS4 drive shafts the same length as the 1.8t? I thought the RS4 had a wider track
do you need RS4 shafts to use S4/RS4 hub carriers or do 1.8t shafts fit into S4 hub carriers at all?
any chance you could post up some pics of the differences in the RS4 drive shaft vs the 1.8t one?

cheers

very topical as i just bought anothe hub carrier and my 8 pot brembos arrive on Wednesday!!
just sold my RS4 calipers to a chap in Spain so I am pretty sure he'd be interested too!

 

[Siena]

RS4 driveshafts are the same length as the 1.8T ones.

RS4 driveshafts run 108mm inner CV joints, as opposed to 100 on a 1.8T quattro. If your 1.8T is FWD, then your inner CV joints will also be 108mm.

The RS4's wider track comes from the ET20 wheels.

The RS4 calipers will NOT bolt up to any uprights, other than S4 / RS4 items.

You MAY be able to run your stock driveshafts with S4 uprights, but your bearings MAY be the 75mm ones. RS4 / S4 run 82mm bearings.

V6 models initially ran 85mm wheel bearings, but only very early cars. Later V6 models ran 82mm ones. My car is a '96 2.6 V6 QS, and has 82mm bearings.

 

[jcb]

RS4 driveshafts are the same length as the 1.8T ones.



You MAY be able to run your stock driveshafts with S4 uprights, but your bearings MAY be the 75mm ones. RS4 / S4 run 82mm bearings.

its this bit I need to check and wasn;t sure about
cheers

 

[B5.5 passat James]

Sorry to bring up a old post, I've got a 2002 b5.5 passat (same underneath as a a4) and have recantly done a brake change to hp-2, to do thus I had tk change the old steal hubs to aluminium ones, in the resurch I have done for it I found that the a6 hubs are the same as the s4 ones, it was a strat bolt of fit including driveshaft the only thing I had to change was the front lower arms as the ball joint was a diffrent taper, one thug to look out for is the Alumanum hubs have inserts between the ball joint and the hub so you have to make sure you have them as vw don't list them as separat parts, I had to get a compleat second hand arm to get it, hope this helps, the main difrance between the hubs other than one is hollow is the bolt spacing for the carage, the steal hubs have a smaller spacing than the aluminium hubs and they bolt through into the carage as opost to into the hub, and the bering are bolt on rarther and push fit, I know hp-2 are diffrent to rs brakes but the bolt spacing is the same as far as I'm aware

 

[RaulQTS]

Anyone fit rs4 b5 back brakes on a 1.8t Quattro
What’s required ?

I have the brakes lines , handbrake cables, discs & pads. What else will I need ?

 

[Broonie]

Calipers, you’ll need them!

All b5 quattro’s has the same rear uprights/subframe/lower wishbones so calipers/carriers bolt straight up only the upper wishbones differ on the RS4 being steel rather than cast on the a/S4