8E0 Rear Brake Upgrade

[Jamo]

@Paul,

Be strong, it's always hardest to go first with these projects. It doesn't help that you have to work on the drive and no one else is around for inspiration.

Maybe we should gather a team together for a project weekend to work it all through and sort out the cables or look into it next time you over this side of the water. If we had it in the air we could have a clear view of what's best and whipping the exhaust off would be a quick job.

Ben

I would have thought this would be ideal especially if you two could arrange to meet at Lions Garage?

[S2 Ant]

Calipers 8E0 615 423C & 8E0 615 424C
Disc 2 x 8E0 615 601R
Carrier 2 x 8E0 615 425B
Pads 4B3 698 451
Hoses 2 x 8E0 611 775H

By my reckoning, these parts come to £764.25 Retail.
Altho, also by reckoning, knowing the right people could almost half that price.
Obviously this is assuming all are purchased from a main stealer.

[s2avant]

@Paul,

Be strong, it's always hardest to go first with these projects. It doesn't help that you have to work on the drive and no one else is around for inspiration.

Maybe we should gather a team together for a project weekend to work it all through and sort out the cables or look into it next time you over this side of the water. If we had it in the air we could have a clear view of what's best and whipping the exhaust off would be a quick job.

@Twoqu

Electromechanical calipers don't have cables as they have electric handbrake mechanisms (which I'm sure you knew already ). Would be a lot of work to convert to them though as they have a control unit that works out pad wear etc to keep the pistons in the right place. Also have to be put into service position via diagnostics computer ( or VAG-COM) to change pads etc as you cannot manually wind back the pistons.

The release is very slow on them as well. My boss has a new Passat and it can take 5-10 seconds for the handbrake to release after you push the button.


Ben

[S2 Ant]

Dunno how i missed this thread but all looks hugely interesting and one i will keep in mind for the future i think.... along with Ben's RS6 upgrade on the front!

[twoqu]

Paul,
Undoubtedly you could get "correct" cables but you would need a Frankencable to recplicate. I guess someone like Speedy Cables (if they are still going!).
Obviously it would be great to get an oe cable. However if you could get/make a kit up of the relevant parts in the right places, then the cable length/ends would be the least of the problems.
I know it sounds like a lot of work but is it more involved than it would be if you were replacing cables as a maintenance issue?
If you were going to all the trouble and expense of upgrading it would be false economy not to replace the original cables. After all I doubt whether it would need doing again in the cars life!
Out of interest, does anyone know whether these funky electro/mechanical hanbrake calipers have a cable. A switch would be easier than a cable!

[S2central.net]

I'm totally with you on that twoqu - I'm 99% certain the Avant cables will do just this - its just the sheer amount of work getting them onto the Coupe is really offputting. Its far from a bolt-on upgrade when it looks like the following is required -

Remove exhaust system
Remove heatshields in the handbrake lever area
Remove old cables
Enlarge the holes on the brackets under the car to accomodate the Avant cables
Modify each Avant cable by removing a stiffening sleeve (which limits bendiness)
Modify each Avant cable further to provide better physical protection under the Coupe
Then finally fit the Avant cables to get smooth routing to the caliper... without causing interference issues with moving suspension parts and driveshaft.

Sorry to sound like I'm going lame on this one - gawd knows I've thrown a lot of money and effort into this but the handbrake problem is a show stopper on the Coupe.

Only nice way round would be if we could get a custom made handbrake cable that had the correct length, fittings, reinforcement and whatnot to work on the Coupe. You'd still need a lot of disassembly to swap the cables over, but at least you wouldn't have the PITA of modifying brackets and bodging Avant cables along the way.

So - last call - does any of the assembled motor trade or 'proper engineers' on here know of a suppiler that we could entrust the manufacture of a custom handbrake to for this project ?

Paul

[twoqu]

Paul,

Would it not be possible to effectively loop the cables the other side of the suspension and then bring them back under to the calipers so that the radius of the cable isn't so tight. Guess you could also cross them over. Might need to find some longer cables!
I'm guessing the problem lies in the fact that you are trying to connect from the normal side and the angle in the bracket is too tight. Whereas if the approach was made from the other side it would be less acute and more in line with the OE fitment.
Just a thought!

[S2central.net]

RS2 discs are sized for 5x130 PCD. The hub centre is wrong size and offsets are all different. That and the RS2 handbrake is notoriously bad - its a funky drum configuration that accompanies the caliper setup.

Paul

[Chris5044]

has anyone not tried the rs2 rear brake setup? .. since it uses front and rear porsche brakes?...

any reason why this shouldnt work? interested to know

[90quattrocoupe]

Hi Paul,
I was thinking along the same lines as you. Turning down the NuS4 rotor to match up with my 280mm rear set up. Went to the stealer and measured the offset on the rotor. It is about the same as the S3/New Beetle rotor, so you will still need to use the spacers behind the carrier. Sorry, but at least it is only turning down the rotor instead of bored and slotted.

By the way, Mark H. is using the light weight A8 calipers, slightly larger piston. I am using the UrS4/S6 caliper. By the way, the sedan ones fit just fine, doesn't need the avant calipers.

Greg W.

[S2central.net]

For the record here is the 8E0 part numbers I have been toying with on the Coupe. It all works a treat except that the Coupe handbrake cannot connect. Lots of disassembly is required to change the handbrake. Based on what I know (the Coupe and Avant use same rear discs and carriers), this conversion would work perfectly on the S2 Avant, but a dry fit is needed to be sure that there are no clearance issues.

Calipers 8E0 615 423C & 8E0 615 424C
Disc 2 x 8E0 615 601R
Carrier 2 x 8E0 615 425B
Pads 4B3 698 451
Hoses 2 x 8E0 611 775H

Note the calipers are trailing edge on the 8E application and the S2 Avant, whereas they are leading edge on the S2 Coupe.

New carrier to hub bolts are required (4 x N019 912 3 for the Coupe) but its 2 pairs of differnt bolts on the Avant as the rear knuckle is an odd shape.

Note also that when changing the brake lines that its a good idea to renew the union clip clamps (2 x 4D0 611 715B).

Note also the handbrake may require a fresh new lock clip (2 x N900 527 02).

These fit under 16" Avus rims (though I never tested that with the handbrake connected).

Paul

[S2central.net]

Had another hour or so tinkering in the garage with an assortment of 8E0 rear brakes and the S2 Avant handrake cables. These hook up to each other perfectly. Photos to come... There is just no way to run with the Coupe handbrake cable and the effort required to change the Coupe cable to Avant is just too much in the mindset of a simple bolt-on upgrade for me.

So here's the next bit of thinking - a hybrid rear setup as follows -

8E0 300x22mm rear discs (machined down to 280mm) - bolt straight on
S8 rear carriers for 280x22mm discs (a la MarkH) - bolt straight on I reckon
UrS4/S6 Avant rear calipers - bolts straight on and have correct h'brake for Coupe

Alternate calipers are the sexy light alloy ones from S8 or S6+ as dimensions and topology are otherwise the same.

Note if referring to MarkH's mighty work on this subject before that he needed spacers and longer carrier bolts because he was using 280x22mm discs from the front of an A3 (machined for correct bolt spacing and centre hole) which had a 3mm difference in height from the S2 disc. I'm fairly confident spacers and such won't be needed with the S8 brackets on the machined down 8E0 discs.

I'm going to sleep on this one cos it means spending more damn money - but it means there will be a set of 8E0 calipers, carriers and pads for anyone mad enough to prove my theory that this will bolt straight onto an S2 Avant. Ben would be the man of course except he is waiting for 2007 rear calipers to come available. Any takers ?

Paul

[Ross]

Paul, you're a star doing all this work... seems like this one isn't as simple as hoped, but still very much interested here!

[S2central.net]

i hope so

Here's a picture of stock calipers from the rear of an S2 Avant that I was working on ages ago. They are pretty much identical format to the 8E0 caliper with regards handbrake. Only issue is if they have clearance issues with rear suspension leg on the Avant.

Compare the pic with those I published on my mac.com pages way back near the start of this thread. Rear avant calipers are trailing - same as these 8E0 jobs... Unlike the Coupe which has a leading caliper position.

Paul

[Jon441cc]

Rest assured I will be trying this on my Avant soon.

Ben

i hope so