View Full Version : DIY: 255mm s4 rear brake swap
03-20-2010, 10:08 PM
ok, so i've been getting all kinds of PM's about my rear brake swap since i did it. i wanted to show how to do this swap, but do it so even a total noob could atempt it. so sorry if it's too step by step. i just wanted to be as detailed as possible for those that haven't worked on their rear brakes before.
i've had these pictures saved for about four months, so forgive me if i don't have everything exactly right.
ok, so first i'll show you the reason for doing this swap.
you'll be going from this:
-C5 A6 2.7T: 245mm diameter, 10mm thick, 45mm offset. Solid disc.
Vented, 255mm diameter, 22mm thick, 25mm offset.
this isn't a massive upgrade, but you do get a few advantages. you get vented rotors, a 10mm larger rotor diameter, and a little lighter caliper. it does give you a chance to upgrade to stainless lines, but you don't have to, your stock lines should work.
03-20-2010, 10:09 PM
now that that's out of the way lets begin.
this is my last setup i had stock sized drilled/slotted rotors from R1 concepts and liked them a lot. the only reason i did the swap was because i already had the calipers, carriers, pads, and lines from a 300mm rear brake swap i had planed but didn't do because i didn't like the fitment. so it only made sense for me to get rotors and use what i already had.
for this swap I used the following, you don't have to use these exact parts if you want to save some cash:
used B5 S4 calipers & carriers
rear brake hardware kit
Hawk HPS pads for a B5 S4/C5 a6 (same pads you already have)
034 motorsport stainless extended brake lines (from 300mm rear BBK)
you'll have to e-mail them for just the lines
Meyle B5 s4 rear rotors
and you'll need some DOT 4 brake fluid to top off your reservoir after you bleed your brakes. i just picked up some cheap stuff from autozone until my super blue came in from jhm, stupid UPS won't let you ship fluids anything but ground [evilmad]
lets start with the e-brake cable. first pop out the retaining clip with a flat screw driver
next wedge the screw driver in the lever and push it toward the rear of the car, and remove the cable. if you can't get it that way there's a 12 or 13mm bolt on the back of the caliper holding on the bracket. take that out and you can remove the cable that way.
once those are off it just needs to be pulled though the bottom. it's a good idea to put the clip back in so you don't loose it
now that that's out of the way you can remove the two 13mm bolts holding on the caliper. you'll need to hold the nut on the carrier or the bolt will just spin. i used a 5/8 wrench because it's the only one i had that would fit between the caliper and the carrier. i think the correct size is a 14mm.
after you remove the two 13mm bolts the caliper will just slide off. pull the pads out of the carrier. they just rest in the slots.
on the back side of the carrier there are two 8mm allen bolts holding it on the hub. remove them and the carrier will come off. after that the rotor just slides off. if it didn't fall off already [>_<]
heres a better picture of the 8mm bolt locations.
03-20-2010, 10:09 PM
before you start assembly take the time to clean and paint all your new parts. you'll thank yourself later. if you want the paint to stay on use some high heat paint or some caliper paint. i just painted everything that needed it and wiped off the excess with a rag and some brake clean. i tried masking the rotor surface first but it was too much of a PITA.
a little comparison of the carriers to show you what the size difference is between the rotors. (don't have a side by side comparison of the rotors themselves)
the hardware kit i got included a set of boots for the carriers. if you want to replace them all you need to do is pull the pins out and pop the boots off and on. either way it's a good idea to clean the old grease off with some brake clean and re-grease them.
your new rotors and carriers mount the same way your old ones did with the same 8mm allen bolts.
load your NEW pads. i know your old pads are the same, but you need new ones if you replace the rotors. (don't try to be a cheap ass)
go ahead and get your calipers ready. if you get the 034 lines install them LOOSLY. even if you use your old lines you need to get new crush washers. if your caliper pistons aren't compressed you'll need to apply pressure to it and spin it clockwise.
now it's time to remove your old calipers and lines (or just the caliper) for this i'm going to skip to the passenger side to show you that you need to remove the fender liner to access the fitting. there's about ten T25 screws scattered around and one 10mm nut holding it in. the drivers side you don't need to remove the liner because it's not blocked.
i didn't take any pictures while i was changing the fittings because i wanted to get the least amount of air in the line as possible. but if you get the 034 lines you'll need to assemble it in this order. leave the stock clip in place, just unscrew the top fitting and the line should drop down from the bottom.
go ahead and mount your up your calipers, and attach you e-brake cable. you should have something like this.
(stupid shadow! [headbang])
and your done! say peace out to your old brakes, and get a friend to help you bleed out your lines.
now the fun part breaking them in. [drive]
01-16-2011, 08:21 PM
link to discusion threaad: http://www.audizine.com/forum/showthread.php/352805-s4-rear-brake-swap-for-noobs