8E0 Rear Brake Upgrade

[Skull]

i checked this thread all over again, and so for the avant/limo it is the 300x22, from the a4 b6. any chances of putting something like 280 on the rear?

[NEO]

Hey folks! A new year and a new brake setup! Time to lift this classic thread.

I have finally finished the caliper brackets for my front RS6 brakes (any one interested in buying adapters/brackets for the RS6/RS4-b7 8pot calipers?). So with the front setup almost finished I started to look on my rear set up. A year ago or something I stumbled across the RS4-b7 calipers, brackets and discs. Couldn't resist buying them. I knew that the handbrake would be a problem but thought that it was fixable.

And today I started to test with that setup but pretty soon I ran into problems. The carrier for the RS4-b7 brakes are fitted with M12x1.5mm bolts. And as you know the original brackets are seated with M10x1.25. Soooo... I can't really bolt the carriers on as it look now.

I can see a couple of approaches here.

1. Drill the 10mm holes in the wheel hub to 12mm.
Pro: No modifications needed to the carriers.
Con: Can't fit original brakes again. All my mods are performed so that it can be rebuilt to original. This operation would go against that philosophy.

2. Use some sort of helicoil on the RS4 carriers to make the M12x1.5 into M10x1.25. This might work but it's not 100% certain that it will. Worst case scenario is that I make the carriers useless.
Pro: No mods to the wheel hubs.
Con: Might kill the carriers

3. Look for some other carriers that works with the 324x22 RS4-b7 discs. The S4-b7 swallows 300x22 discs. So 324 would be way to big for those. The RS6 carriers swallows 335x22 discs so they would most probably be to big. Can't find any others that could fit. Anyone know of some carriers that might work for me?
Pro: Bolt on solution.
Con: Hard, if not impossible, to find a carrier like this.

4. Sell this stuffs of and find RS6 stuffs. 335x22 disks and calipers. Those carriers are fitted with M10x1.25. But dunno about the cc on those carriers and the offset on the discs might differ? I know a guy that have had RS6 stuffs at the rear on an S4-b7. Will ask him for some more details about it.
Pro: Might fit better then RS4-b7 and they are BIGGER!
Con: Not easy to find. Not sure if it works.

5. Go with the s4 carriers and machine the discs down to 300mm.
Pro: None except that it will fit.
Con: Smaller brakes.

What I find odd is that Audi didn't use the RS6 rear set up on the RS4-b7. I mean... Those parts were ready for manufacturing and not that much bigger, 11mm in diameter. But they probably had some really good reason for it even if I don't understand it.

I'm not that worried about the handbrake issue. Does not look all to hard to modify it. Would need a wire that is about 10cm longer or so. And maybe re mount it so it comes out in front of the rear sub frame mounts. Then manufacture a mount for it so it approaches the caliper from below.

Anyone with any thoughts about this?

[s2avant]

Having ditched the 8E0 setup in favour of the 4F0 setup (330x22mm) I would suggest you try option 2, the helicoil route. That is what was done on mine and it is fine.

As for the handbrake it is relatively easy to mod the stock cables to fit the bigger setup. 330mm is about as big as you stretch them so your 324mm will be fine.

Ben

[Acidburn]

@ben - presume this is just for avants or could a different cable be used etc to fit it to a coupe?

Also how does it balance out with the front brakes.

[NEO]

Hey man!

Ooooh! So you did go for the 330mm! Haven't seen any pics of that? Have I missed that thread? What parts did you go for? If you fitted helicoil I'm taking it that you didn't go for Rs6 since those are M10x1.25...? or?

So you did drill up the M12's in the carriers and fitted helicoils in them so you converted them to M10x1.25? Do you have any pictures of this? Or links to the specific tools/helicoils you used? That would be much appreciated!

Acidburn: I'm going for RS4-b7 at front and rear. So they should be fairly well balanced I guess. =)

Having ditched the 8E0 setup in favour of the 4F0 setup (330x22mm) I would suggest you try option 2, the helicoil route. That is what was done on mine and it is fine.

As for the handbrake it is relatively easy to mod the stock cables to fit the bigger setup. 330mm is about as big as you stretch them so your 324mm will be fine.

Ben

[s2avant]

Neo,

I hadn't got round to doing a thread but I have just posted one up for you

I haven't got details of the helicoils etc but I'm sure Jason (UR-S4) will come along and fill in the blanks.

Ben

[goodall]

8D0615301A, is a front disc for a audi a4 b5, its 280mm and solid, would mean could use standard caliper not sure what carrier would need to be used

or theres 8E0615301B, its a vented 280mm front disc for a b5 a4, would mean no machining, assuming offset isnt all wrong

[John B]

8E0 Coupe Setup

Ok...

Been studying all the stuff on the site: what great thread. Paul and Ben have persevered for us all to benefit. The holy grail for us Coupe owners is to use the 8E0 set up @ 300mm and resolve the handbrake cable issue once and for all. It would be great to take the neuS4 (B7) standard set up and bolt it on.

What I'm proposing, is to use the Avant cables as they are longer than the Coupe ones in order to allow for the turn from the cable's side approach from the transmission tunnel to the caliper in order to actuate the handbrake in an up/down axis. How this angles without fouling the running gear / exhaust etc and avoiding being exposed to road debris appears to be the crux of the problem.

I'm intending to get:-

Part Number Qty
Disc 8E0 615 601R 2
Neu S4 caliper carrier (black) 8E0 615 425E 2
Neu S4 caliper (black) 8E0 615 423F 1
Neu S4 caliper (black) 8E0 615 424F 1
Pads 4B3 698 451 2
Hydraulic Hose 8E0 611 775H 2
Carrier to Hub Bolts N019 912 3 4
Union Clip Clamps 4D0 611 715B 2
Handbrake Lock Clip N900 527 02 2
Avant Cables 8A0 609 721AD 2

Plus lots of perseverance / swearing etc!!!

Thoughts / tips on routing would be appreciated before I go headlong into the abyss!

Cheers,

John

[Sonic]

Not sure if this helps, i took quite a few photos when i installed the 300x22mm setup cut down to 280mm.

[S2central.net]

Good luck matey... I opted out of doing the handbrake cable extension on the Coupe as I was working on a driveway at the time (rented house for a bit) and there is much potential for that turning into a right bitch of a job... the cables run up close to exhaust and propshaft and there are some heatshields up there which aren't going to help either. The routing of the cable is more complex than you might think.

If you are prepared to potentially take lots of stuff off to achieve this then OK, but I took the easy option of getting the 300mm disc reduced to 280 at very little cost in a local machine shop.

Bolt on. Drive off !

My advice to you is spend an hour under the car studying your options - maybe buy the Avant cables first to see what distances you have to play with. There are some big rubber boots and insulators on the avant cables which make it more difficult to re-use the Coupe hbrake mountings and routing holes... Its just not as simple as a longer cable - the whole rear end of B4 avant/limo is very diffrent to B3 Coupe. I'd strongly advise you do NOT buy all the 8E0 calipers and stuff for your Coupe until you are confident about the handbrake solution.

I'm sure that I bought Avant cables when I researhed this ages ago - I have a recollection of bodging the mounts/rubbers off on one of them to explore something. I'll look in the garage for the other cable - you are welcome to it if it helps you explore without spending lots of money.


Paul

[John B]

Handbrake cable madness

It just seems a damn shame that we can't use the S4 setup just because of some cable routing.

Paul's thread mentions some of the issues regarding routing but he has probably got totally p***ed off with the whole thing not all was documented on the forum especially when the chink of light came with the RR caliper / 280mm disc setup.

Paul, if you have any pictures / bits that you can let me have that would be great. I'll pay postage of course.

Andy, thanks for the pic: looks good

Cheers,

John

[Ross]

I can't find it anywhere and reading all these old brake threads is distracting me from some urgent work I need to get done - but, I'm sure somewhere Paul was discussing a possible 'poor mans' rear brake conversion for the Avant, using the same discs turned down to 280mm and a different carrier/caliper set-up? Did anything come of this, or is a guinea-pig required :mischeif:

[John B]

Ross, the Coupe 8E0 conversion was done by Paul but used a turned down disc (300 to 280) and RR calipers. What I'm attempting to do is carry on Paul's work with trying to use the full 8E0 setup from the S4 and resolve the handbrake cable routing problem as the S2 Coupe uses side pull whereas S4 uses down-pull with the caliper leading orientation that the S2 coupe has. Cheers anyway.

[auditude]

280mm conversion

I'll be doing the 280mm conversion pretty soon on my CQ. I just installed KW coilovers on it late last night and then went for a test drive. Much better than stock I must say, which was Bilstein's on original springs.

I'm going to mock up some of the reportedly bolt-on parts and make sure I have everything (need to buy lines still) to do the 928gts (big blacks) up front on A8L 322mm(?) rotors with RS2 brackets, and in the rear I have the V8S4 rotors already turned down to 280mm, and S8 brackets waiting. The problem is my 200q20v rear calipers are seized, so I'm told I can soak them in a bucket of diesel fuel for a week or so to free them. Once I know the parts I've collected are complete and work, I'll be swapping in the S2 hubs and putting the brakes on. I have to do it at the same time because I don't have 5 bolt standard brakes to use in between.

[Greg_S]

Ok...

Been studying all the stuff on the site: what great thread. Paul and Ben have persevered for us all to benefit. The holy grail for us Coupe owners is to use the 8E0 set up @ 300mm and resolve the handbrake cable issue once and for all. It would be great to take the neuS4 (B7) standard set up and bolt it on.

What I'm proposing, is to use the Avant cables as they are longer than the Coupe ones in order to allow for the turn from the cable's side approach from the transmission tunnel to the caliper in order to actuate the handbrake in an up/down axis. How this angles without fouling the running gear / exhaust etc and avoiding being exposed to road debris appears to be the crux of the problem.

I'm intending to get:-

Part Number Qty
Disc 8E0 615 601R 2
Neu S4 caliper carrier (black) 8E0 615 425E 2
Neu S4 caliper (black) 8E0 615 423F 1
Neu S4 caliper (black) 8E0 615 424F 1
Pads 4B3 698 451 2
Hydraulic Hose 8E0 611 775H 2
Carrier to Hub Bolts N019 912 3 4
Union Clip Clamps 4D0 611 715B 2
Handbrake Lock Clip N900 527 02 2
Avant Cables 8A0 609 721AD 2

Plus lots of perseverance / swearing etc!!!

Thoughts / tips on routing would be appreciated before I go headlong into the abyss!

Cheers,

John

Did you try using the avant handbrake cable in the end or opt for the 280mm option?