Question about rear brake upgrade to 300mm.

[Blur2u]

I have a late model 2001 audi a4 1.8TQ and been wanting to upgrade to 300mm rotors for the rears.

I know i have to purchase a bracket to extend the calipers in order to support the larger diameter.

My question is do i need to buy B5 s4 carriers and calipers or can i use my existing carrier and caliper? I heard for early model B5 a4 you need to upgrade the caliper/carrier, but for late model B5 a4's you can reuse them for this upgrade. I've search and there seems to be no definitive answer if late model A4's can have the calipers/carriers reused.

Has anyone here with a late model b5 A4 who's done the upgrade care to chime in?

Thanks in Advance.

[redline380]

You cannot reuse the calipers on any A4 in any year, and I'll tell you why.

Audi has yet to equip an A4 model (at least with the base engine option) with vented discs. The discs are much wider on s cars, and so is the caliper. The a4/s4 calipers are incredibly identical, identical enough to use the same pads even. However, the s4 calipers are wider to accommodate the wider vented rotor.

Thus, you need to have b5 s4 calipers in order to fit the wider rotor if you want to upgrade to the 300mm rotor, or any rotor that is vented. You would never fit an a4 caliper over a vented disc, at least with pads installed.

[a4kamila6]

I was wondering this myself. Good info ^

[nynoah]

If you want S4 rear calipers go to Autozone and get rebuilds. Then throw your old A4 ones in the box as your core.

[GrapeBandit]

If you want S4 rear calipers go to Autozone and get rebuilds. Then throw your old A4 ones in the box as your core.

no.
you can score both rear calipers from rockauto for $80 lol
http://www.rockauto.com/en/catalog/a...b,caliper,1704

[Blur2u]

Thanks for the replies! Great info Redline, at least now we'll know in case someone else is wondering.

I'll go ahead and order some S4 calipers and carriers to go along with a bracket and 300mm rotors.

[Davdraco1]

no.
you can score both rear calipers from rockauto for $80 lol
http://www.rockauto.com/en/catalog/a...b,caliper,1704

They want 80$ a pieces. It just says thy are sold in pcos of two, then says lricing is per unit. Kinda stupid.

[nynoah]

They want 80$ a pieces. It just says thy are sold in pcos of two, then says lricing is per unit. Kinda stupid.

same price as autozone... lol

[GrapeBandit]

they are 40 after you return the cores

[redline380]

Come on guys, returning a4 cores for s4 cores? Let's not be like that.

If you want to do it right, find a cheap pair from a part out or car-part.com and rebuild them yourself.

[czum09]

So this upgrade is for all a4's? Or do you need different knuckles?

[redline380]

So this upgrade is for all a4's? Or do you need different knuckles?

All b5 a4's have the same brakes (let's not bring FWD into this). S4 rears will bolt right up, front brakes need s4 uprights. Same for every quattro B5.

[OverSpun]

All b5 a4's have the same brakes (let's not bring FWD into this). S4 rears will bolt right up, front brakes need s4 uprights. Same for every quattro B5.

And needs e.g. 034's carrier for this rear S4 caliper upgrade, right?

[ricekikr]

And needs e.g. 034's carrier for this rear S4 caliper upgrade, right?

Yup.

[OverSpun]

Yup.

Ya, to remind the OP.

[redline380]

Ya, to remind the OP.

Only for the 300mm upgrade. If you want to use stock 256mm rotors, only the caliper and carrier are needed.

[OverSpun]

Only for the 300mm upgrade. If you want to use stock 256mm rotors, only the caliper and carrier are needed.

Ya, seems like he's interested in a 300mm.

[walky_talky20]

If you're buying S4 rears, just get C5 A6 4.2 rears. Same caliper, but you get the taller bracket for 269mm rotors. I guess the only downside is the dust shields don't fit. I just took them off. Nobody died.

[Bordom]

If you're buying S4 rears, just get C5 A6 4.2 rears. Same caliper, but you get the taller bracket for 280mm rotors. I guess the only downside is the dust shields don't fit. I just took them off. Nobody died.

C5 4.2 rotors to work with those?

Everything graciously mispelled by Android

[walky_talky20]

Nope. C5's (and especially the 4.2's) have funky offsets. You want D2 A8 4.2 (269mm) rear rotors. The offset is almost exactly correct. You need a single 2mm washer in between the bracket and the upright for the A4 application.

Also, there may be a slight gotcha on the brake line hookup. I believe it uses a banjo bolt instead of the flare fitting on the B5 S4. I upgraded to stainless lines at the same time, so I got C5 4.2 rear lines instead of B5 rear lines. All good.

*And just realized I brain farted. The rotor size is 269mm, not 280mm. I believe 280mm is the S6 size or something. Corrected above post, too.

[redline380]

Nope. C5's (and especially the 4.2's) have funky offsets. You want D2 A8 4.2 (269mm) rear rotors. The offset is almost exactly correct. You need a single 2mm washer in between the bracket and the upright for the A4 application.

Just wanted to make clear that not all d2 a8 rear rotors are the same. My 97 had solid discs.

[Blur2u]

Thanks OverSpun, going to get either the Apikol or 034 brackets for the 300mm rears. I currently run the Apikol brackets for the 17z's up front and it's a great piece.

Ya, to remind the OP.

[redline380]

I bought the 034 brackets. Can't remember why, but there is a reason. Probably because of price.

[OverSpun]

Thanks OverSpun, going to get either the Apikol or 034 brackets for the 300mm rears. I currently run the Apikol brackets for the 17z's up front and it's a great piece.

Who else makes brackets for the 17z's?

I bought the 034 brackets. Can't remember why, but there is a reason. Probably because of price.

Yea, seems like the price after looking.

[Blur2u]

I only know of Apikol who makes brackets for 17z's on our B5 platforms for the A4's, unless you can get it custom made at a machine shop. I have to say though that Apikol's bracket is very solid and hefty.
I also remember there was a little bit of modification that needs to be done, you need to grind some of either the caliper or the bracket bolt to get it to fit (I dont' remember exactly since it's been so long but i can find out if you need the info), very minor modification. Also you will need a shim that apikol sells that will center the caliper to the rotor, i think the shim is 2mm thick.

Who else makes brackets for the 17z's?



Yea, seems like the price after looking.